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第十七届全国核物理大会

Asia/Shanghai
华中师范大学

华中师范大学

武汉
Description
第十七届全国核物理大会暨第十三届会员代表大会将于2019年10月8-12日在湖北武汉举行。受中国核物理学会委托,华中师范大学物理科学与技术学院与夸克与轻子物理教育部重点实验室暨粒子物理研究所将承办本次会议。会议诚挚邀请科研院所、高等院校和其它相关单位的核科技工作者与会交流和探讨核物理研究的最新成果及进展。会议将邀请知名学者专家做大会报告。 会议议题: 1.核结构和高自旋态物理 2.放射性核束和核天体物理 3.低中能核-核碰撞 4.聚变和裂变动力学 5.超重核合成与反应机制 6.不稳定核反应和核结构 7.强子物理 8.核物质状态方程与对称能 9.中高能核物理 10.强作用相变 11.最子色动力学 12.加速器和核探测仪器及制靶技术 13.核技术应用和核反应堆物理与材料 14.其它核物理相关领域 重要日期节点: 一轮通知:2019年4月5日 二轮通知:2019年6月10日 截稿日期:2019年8月20日 会议注册截止:2019年9月15日 三轮通知:2019年9月30日 会议日程:2019年10月8-12日 会议注册需要先注册一个高能所indico系统的账号,如果您没注册过,请先点击该链接先注册:http://indico.ihep.ac.cn/user/register 然后您再通过会议 Indico 主页的左侧“注册会议”链接进行注册(目前注册页面仍在建设中,请关注新的通知) 注册过程您有问题可通过大会主页 http://cnpc2019.ccnu.edu.cn 中的“联系我们”进行沟通。谢谢! 主办方:中国核物理学会 承办方:华中师范大学,华南师范大学 赞助单位:教育部、中国科学与技术部、国家自然科学基金委、中国高等科学技术中心,湖北省核学会等
Participants
  • Aman Rohilla
  • Baochi Fu
  • Ben-Wei Zhang
  • Bin QI
  • Bingsong ZOU Bingsong
  • bosong huang
  • Chen Liu
  • Chunlin Bai
  • cuimei hou
  • Dan PENG
  • Defu Hou
  • Fangfang Duan
  • Feng-Kun Guo
  • Feng-Shou ZHANG
  • Fengqiong Liu
  • Fupeng Zhong
  • Fuyan Liu
  • Gaolong Zhang
  • Guang-You Qin
  • guangyao sun
  • guo yang
  • guo-yun Shao
  • Guozhu Shi
  • Hao Lu
  • Hong-Zhong Wu
  • Hongbin Zhang
  • Honglin Ge
  • Horst Stoeker
  • Hu Shipeng
  • Huan Chen
  • Huan Zhong Huang
  • Hui Hua
  • hui jia
  • Huiming Jia
  • Jia Wang
  • jiangshan lan
  • Jianguo Li
  • Jianling Lou
  • jiansong wang
  • Jifeng Han
  • Jinchuan Wang
  • Jing Wu
  • Jing Zhang
  • Jingjun ZHU
  • Jun Xu
  • Jun-Hao Cheng
  • Junbing MA
  • Junchen Pei
  • kai Li
  • Kai Zhang
  • Kailing Zu
  • Kang Wang
  • Lei Yang
  • Liang Chen
  • Lianrong Dai
  • Lin Gan
  • Lu-Meng Liu
  • Mei HUANG Mei
  • Mingli Wan
  • Moran Jia
  • Mukhi Kumar Raju
  • Nicolas Michel
  • Nihar Sahoo
  • Niu Wan
  • Peng Ma
  • Qian Yang
  • Qian Zhan
  • Qiang ZHAO
  • Qijun Zhi
  • Qinghua He
  • Qiye Shou
  • Quan Liu
  • Rui Wang
  • Sheng-Qin Feng
  • Shi Pu
  • Shouyu Wang
  • SHUO WANG
  • Shuo Yang
  • Somnath Kar
  • Suqing Hou
  • Tihui Wang
  • WEI CHENG
  • Wei Ji
  • Weicheng Li
  • Weiwei QU
  • Wen Hui LONG
  • Wenda Guo
  • Wujie Li
  • Xian-Hui Zhong
  • Xiaobao Wang
  • Xiaoliang Zou
  • XIAOMING ZHANG
  • Xiaowei Luo
  • Xingchi Han
  • xinye peng
  • Xiujun Li
  • xiuling zhang
  • Xiuxiu Jiang
  • Xuhao Wu
  • Yafei Wang
  • yahong xie
  • Yang ZOU
  • Yanlin Ye
  • Yaping Wang
  • Yaxian Mao
  • Yayun He
  • Yi Yin
  • Yifei Zhang
  • yingjie zhou
  • Yipu LIU
  • Yong-Zhong Xing
  • Yongqin Ju
  • Yongsheng Wang
  • Yu Fu
  • Yu Zhang
  • Yu-Gang Ma
  • Yuan Qiu
  • Yuan Tian
  • Yuan Yao
  • Yushan Zhou
  • Zebo Tang
  • Zeyu Zhai
  • Zhang Biao
  • Zhao Zhang
  • Zhen LIU
  • Zheng LIU
  • Zhenyu Chen
  • Zhi-Hui Guo
  • Zhilei SHE
  • Zhishuai Ge
  • Zhongbao Yin
  • Zhumin ZHAO
  • Zhumin ZHAO
  • Ziwei Lu
  • ZIXU XU
  • Ziyang Li
  • 一斐 牛
  • 世绍 鲍
  • 世陶 王
  • 丙岩 刘
  • 业英 孙
  • 东 刘
  • 东玺 王
  • 东风 陈
  • 中洲 任
  • 丰群 周
  • 丹阳 庞
  • 乃波 张
  • 义俊 庞
  • 书卿 袁
  • 二涛 李
  • 亦轩 赵
  • 亨通 丁
  • 人洲 郑
  • 仁刚 张
  • 仁杰 王
  • 代翠 周
  • 伏龙 刘
  • 伟 朱
  • 伟力 孙
  • 佳杰 沈
  • 佳欢 朱
  • 俊 苏
  • 俊岭 陈
  • 俊杰 何
  • 俊杰 张
  • 俊生 李
  • 保华 孙
  • 健宏 黎
  • 兆庆 冯
  • 先概 邓
  • 克岩 马
  • 兴忠 曹
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  • 再国 甘
  • 军 苏
  • 冰倩 周
  • 冶秋 贺
  • 凡 司
  • 凤仙 刘
  • 凯旋 程
  • 刚 陈
  • 创业 贺
  • 剑 李
  • 剑锟 赵
  • 卫平 柳
  • 厚军 何
  • 吉峰 黄
  • 向伦 魏
  • 向前 冯
  • 国亮 马
  • 国峰 曲
  • 国青 肖
  • 大庆 袁
  • 太平 彭
  • 奇 曾
  • 奇玮 张
  • 娜 费
  • 婉莎 杨
  • 存 王
  • 学胜 焦
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  • 小红 周
  • 小艳 韵
  • 小飞 吴
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  • 岫鸟 赵
  • 峰 潘
  • 巍 叶
  • 广生 李
  • 广顺 李
  • 庆华 徐
  • 庆峰 李
  • 庆章 赵
  • 建东 张
  • 张莉 郭
  • 强 赵
  • 强华 吴
  • 彦云 杨
  • 彩万 沈
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  • 德鑫 王
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  • 志强 陈
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  • 怀民 陈
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  • 恩科 王
  • 慧 孙
  • 成 李
  • 成名 杜
  • 成波 李
  • 承键 林
  • 振东 安
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  • 振鹏 陈
  • 敬雅 范
  • 文学 黄
  • 文庆 沈
  • 文政 许
  • 文杰 谢
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  • 斌 洪
  • 新年 王
  • 新星 徐
  • 早春 高
  • 旭 许
  • 旭光 黄
  • 昊楠 潘
  • 昌 许
  • 明 何
  • 明明 张
  • 昕玥 刁
  • 星泉 刘
  • 春旺 马
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  • 晓 陆
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  • 杨 雷
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  • 柏松 谢
  • 树亚 金
  • 根 张
  • 梳苏 施
  • 正国 胡
  • 武律 钟
  • 毅 张
  • 永得 方
  • 江华 贾
  • 治纬 杜
  • 泺欢 王
  • 洁琼 蒋
  • 洪涛 沈
  • 浩强 师
  • 浩浩 彭
  • 海波 桑
  • 海瑞 郭
  • 海福 赵
  • 海锐 段
  • 涛 叶
  • 潇祎 李
  • 炜 张
  • 炜平 林
  • 焕乔 张
  • 燕 李
  • 燕春 丁
  • 爽 张
  • 猛 王
  • 玉林 田
  • 玉鑫 刘
  • 王妹 查
  • 玮雯 邓
  • 琛琛 郭
  • 琳 程
  • 琳 穆
  • 瑚珊 徐
  • 瑞 韩
  • 瑞利 王
  • 璐瑶 童
  • 甫荣 许
  • 甫鹏 李
  • 相满 刘
  • 睿巨 郭
  • 祎萍 许
  • 福虎 刘
  • 秉然 何
  • 立勇 张
  • 立升 耿
  • 笛 吴
  • 素华 郑
  • 继召 刘
  • 继红 魏
  • 维娟 赵
  • 群 王
  • 翊 谢
  • 翔舟 蔡
  • 联毅 何
  • 胜奇 冯
  • 航 张
  • 良娣 霍
  • 良志 曹
  • 艳丽 杨
  • 艳召 王
  • 艺伟 郝
  • 苏雅拉吐 张
  • 茂武 聂
  • 荣 王
  • 荣 王
  • 荣华 李
  • 莉莉 赵
  • 莹 崔
  • 菁华 付
  • 菲 牛
  • 蓉 李
  • 衡讷 李
  • 豪 王
  • 贺润 杨
  • 赟华 强
  • 辉淦 程
  • 迎迎 史
  • 远卓 马
  • 邦角 叶
  • 金成 王
  • 金根 陈
  • 鑫 张
  • 钧 胡
  • 铁山 王
  • 锦霞 程
  • 长波 符
  • 阳帆 何
  • 静雅 吴
  • 韩奎 王
  • 颖 袁
  • 飞 李
  • 驰 杨
  • 骁 肖
  • 骅 裴
  • 高产 雍
  • 鹏 刘
  • 鹏程 李
  • 鹏飞 王
  • 龙 祝
    • 10:00 AM 8:00 PM
      Registration 桂苑宾馆

      桂苑宾馆

      华中师范大学

      武汉
    • 8:00 AM 8:30 AM
      Registration 科学会堂

      科学会堂

      华中师范大学

      武汉
    • 8:30 AM 9:24 AM
      开幕式,理事长工作报告,胡济民奖 科学会堂101

      科学会堂101

      华中师范大学

      武汉
      Convener: Prof. 代翠 周 (Central China Normal University)
      slides
    • 9:24 AM 10:20 AM
      胡济民奖获奖工作展示 科学会堂101

      科学会堂101

      华中师范大学

      武汉
      Convener: Prof. Yanlin Ye (Peking University)
      • 9:24 AM
        Report 1 7m
        Speaker: Dr Feng-Kun Guo (ITP, CAS)
        Slides
      • 9:31 AM
        Report 2 7m
        Speaker: Xu-Guang Huang (Fudan University)
        Slides
      • 9:38 AM
        Report 3 7m
        Speaker: Dr 建玲 楼 (北京大学)
        Slides
      • 9:45 AM
        Report 4 7m
        Speaker: Prof. Baohua Sun (Beihang University)
        Slides
      • 9:52 AM
        Report 5 7m
        Speaker: Dr Cenxi YUAN (Sun Yat-sen University)
        Slides
      • 9:59 AM
        Report 6 7m
        Speaker: 志远 张 (Institute of Modern Physics, CAS)
        Slides
      • 10:06 AM
        Report 7 7m
        Speaker: 武律 钟 (SWIP)
        Slides
      • 10:13 AM
        Report 8 7m
        Speaker: jiangshan lan (Institute of Modern Physics)
        Slides
    • 10:20 AM 11:00 AM
      理事选举,照相,茶歇
      Convener: 东风 陈
      GroupPhoto
    • 11:00 AM 12:00 PM
      大会邀请报告 科学会堂101

      科学会堂101

      华中师范大学

      武汉
      Convener: Yu-Gang Ma (Shanghai Institute of Applied Physics, CAS)
      • 11:00 AM
        Experimental studies on the isospin transport and the asymmetric nuclear equation of state in heavy ion collisions 30m
        Speaker: Prof. 志刚 肖 (Tsinghua University)
        Slides
      • 11:30 AM
        阈值效应与强子奇特态寻找 30m
        Speaker: Prof. Qiang ZHAO (Institute of High Energy Physics, Chinese Academy of Sciences)
        Slides
    • 12:00 PM 2:00 PM
      午餐 2h 桂苑宾馆

      桂苑宾馆

      华中师范大学

      武汉
    • 2:00 PM 4:00 PM
      大会邀请报告
      Conveners: Prof. Mei HUANG (IHEP, CAS) , 恩科 王 (CCNU)
      • 2:00 PM
        MAGIC-Matter in Astrophysics, Gravitationalwaves, and Ion Collisions 30m 科学会堂101

        科学会堂101

        华中师范大学

        武汉
        Speaker: Dr Horst Stoecker (GSI)
      • 2:30 PM
        原子能院核物理应用研究进展 30m 科学会堂101

        科学会堂101

        华中师范大学

        武汉
        Speaker: Prof. 东风 陈 (中国原子能科学研究院)
        Slides
      • 3:00 PM
        基于精密激光谱学的不稳定核结构研究 30m 科学会堂101

        科学会堂101

        华中师范大学

        武汉
        Speaker: 晓菲 杨 (北京大学)
        Slides
      • 3:30 PM
        CSR短寿命原子核质量的高精度测量 30m 科学会堂101

        科学会堂101

        华中师范大学

        武汉
        Speaker: 猛 王 (impcas)
        Slides
    • 4:00 PM 4:30 PM
      茶歇 30m 科学会堂

      科学会堂

      华中师范大学

      武汉
    • 4:30 PM 6:00 PM
      大会邀请报告 科学会堂101

      科学会堂101

      华中师范大学

      武汉
      Conveners: Prof. Ben-Wei Zhang (Central China Normal University) , Mr Guoqing Xiao (Institute of Modern Physics,Chinese Academy of Sciences)
      • 4:30 PM
        我国核数据研究现状与未来展望 30m
        Speaker: Prof. 智刚 葛 (中国原子能科学研究院)
        Slides
      • 5:00 PM
        Quark-Gluon Plasma and Relativistic Heavy-Ion Collisions 30m
        Speaker: Guang-You Qin (Central China Normal University)
        Slides
      • 5:30 PM
        Symmetries and their breaking of strong interaction system 30m
        Speaker: Yuxin Liu (PKU)
        Slides
    • 6:00 PM 7:00 PM
      S5: Poster分会场: 张贴墙报为第二天展示做准备 科学会堂

      科学会堂

      华中师范大学

      武汉
      • 6:00 PM
        A microscopic description for polarization in particle scatterings 1h
        We propose a microscopic description for the polarization from the first principle through the spin-orbit coupling in particle collisions. The model is different from previous ones based on local equilibrium assumptions for the spin degree of freedom. It is based on scatterings of particles as wave packets, an effective method to deal with particle scatterings at specified impact parameters. The polarization is then the consequence of particle collisions in a non-equilibrium state of spins. The spin-vorticity coupling naturally emerges from the spin-orbit one encoded in polarized scattering amplitudes of collisional integrals when one assumes local equilibrium in momentum but not in spin.
        Speaker: Mr Junjie Zhang (university of science and technology of China)
      • 6:00 PM
        Anomalous magnetohydrodynamics with longitudinal boost invariance and chiral magnetic effect 1h
        We study relativistic magnetohydrodynamics with longitudinal boost invariance in the presence of chiral magnetic effects and finite electric conductivity. With initial magnetic fields parallel or anti-paralleltoelectricfields, wederivetheanalyticsolutionsofelectromagneticfieldsandthechiral number and energy density in an expansion of several parameters determined by initial conditions. The numerical solutions show that such analytic solutions work well in weak fields or large chiral fluctuations. We also discuss the properties of electromagnetic fields in the laboratory frame.
        Speaker: 仁杰 王 (University of Science and Technology of China)
      • 6:00 PM
        Bayesian Inference of High-density Nuclear Symmetry Energy from Radii of Canonical Neutron Stars 1h
        Using the representative $R_{1.4}$ data in the literature, we infer the high-density nuclear symmetry energy $E_{\rm{sym}}(\rho)$ and the associated nucleon specific energy $E_0(\rho)$ in symmetric nuclear matter (SNM) within a Bayesian statistical approach using an explicitly isospin-dependent parametric Equation of State (EOS) for nucleonic matter under several general conditions required for all NS models. The most important new physics we learned from this study are: (1) The available astrophysical data can already improve significantly our knowledge about the $E_0(\rho)$ and $E_{\rm{sym}}(\rho)$ in the density range of $\rho_0-2.5\rho_0$ compared to what we currently know about them based mostly on terrestrial nuclear experiments and predictions of nuclear many-body theories. In particular, the symmetry energy at twice the saturation density of nuclear matter is determined to be $E_{\mathrm{sym}}(2\rho_0)$ =39.2$_{-8.2}^{+12.1}$ MeV at 68\% confidence level approximately independent of the EOS parameterizations used. However, at higher densities, the 68\% confidence boundaries for both the $E_0(\rho)$ and $E_{\rm{sym}}(\rho)$ diverge depending strongly on the EOS parameterizations used and several other uncertainties.(2) The radius data and other general conditions, such as the observed NS maximum mass and causality condition introduce strong correlations for the high-order parameters used in parameterizing the $E_0(\rho)$ and $E_{\rm{sym}}(\rho)$.(3) The value of the observed maximum NS mass and whether it is used as a sharp cut-off for the minimum maximum mass or through a Gaussian distribution in the Bayesian analyses affect significantly the lower boundaries of $E_0(\rho)$ and $E_{\rm{sym}}(\rho)$ only at densities higher than about $2.5\rho_0$.
        Speaker: Dr Wen-Jie Xie (Yuncheng University)
      • 6:00 PM
        Beyond mean-field description of key nuclear physics inputs for r-process study 1h
        Nuclear β-decay half-lives set the time scale of the rapid neutron capture process (r-process), and hence are important for understanding the origin of heavy elements in the universe. In β-decay process, the dominant transition is the Gamow-Teller (GT) transition. As a widely used microscopic model for GT and β-decay study, quasiparticle random-phase approximation (QRPA) has its limitations in reproducing the resonance width, and often overestimates β-decay half-lives. To overcome these problems, beyond mean-field effect, i.e., the quasiparticle-vibration coupling (QPVC), are included on top of QRPA model in a self-consistent way. With this model, we successfully reproduce the experimental GT resonance width and beta-decay half-lives at the same time in both magic nuclei and superfluid nuclei. The interplay of QPVC and isoscalar pairing are studied in detail.
        Speaker: Yifei Niu (L)
      • 6:00 PM
        Effect of the chiral phase transition on axion mass and self-coupling 1h
        We compute the effect of the chiral phase transition of QCD on the axion mass and self-coupling; the coupling of the axion to the quarks at finite temperature is described within the Nambu–Jona-Lasinio model. We find that the axion mass decreases with temperature, following the response of the topological susceptibility, in agreement with previous results obtained within chiral perturbation theory at low and intermediate temperatures. As expected, the comparison with lattice data shows that chiral perturbation theory fails to reproduce the topological susceptibility around the chiral critical temperature, while the Nambu–Jona-Lasinio model offers a better qualitative agreement with these data, hence a more reliable estimate of the temperature dependence of the axion mass in the presence of a hot quark medium. We complete our study by computing the temperature dependence of the self-coupling of the axion, finding that this coupling decreases at and above the phase transition. The model used in our work as well as the results presented here pave the way to the computation of the in-medium effects of hot and/or dense quark-gluon plasma on the axion properties.
        Speaker: Dr 振烟 陆 (ITP, CAS)
      • 6:00 PM
        Evaluation of the chiral condensate in cold quark matter and the pion-nucleon sigma term 1h
        We calculate the chiral condensate in cold quark matter in Dyson-Schwinger equation approach of QCD. Different ansatz for the quark-gluon vertex and the effective interactions are investigated. Then, using a model-independent formula from the Feynmann-Hellmann theorem, we evaluate the pion-nucleon sigma term. We obtain the value of sigma term about 60 MeV, which weakly depends on our different model ansatz and is consistant with recent experimental results.
        Speaker: Dr Huan Chen (China University of Geosciences (Wuhan))
        Poster
      • 6:00 PM
        Extracting high-density symmetry energy from the observations of neutron stars and gravitational waves 1h
        By numerically inverting the Tolman-Oppenheimer-Volkov (TOV) equation using an explicitly isospin-dependent parametric Equation of State (EOS) of dense neutron-rich nucleonic matter, a restricted EOS parameter space is established using observational constraints on the radius, maximum mass, tidal deformability and causality condition of neutron stars (NSs). Rather robust upper and lower boundaries on nuclear symmetry energies are extracted from the observational constraints up to about twice the saturation density $\rho_0$ of nuclear matter. Moreover, the absolutely maximum mass of neutron stars is found to be 2.40 Msun. In addition, we study the implications of the very recently reported mass M = 2.17 Msun of PSR J0740+6620 on the equation of state (EOS) of super-dense neutron-rich nuclear matter with respect to existing constraints on the EOS based on the mass M = 2.01 Msun of PSR J0348+0432 and found some of the most widely used and previously well tested model EOSs are hard to simultaneously predict a maximum mass higher than 2.17 Msun and a pressure consistent with that extracted from GW170817.
        Speaker: Mr naibo zhang (shandong university, weihai)
      • 6:00 PM
        Finite particle number description of nuclear matter using the unitary correlation operator and high-momentum pair methods 1h
        By using the unitary correlation operator and high-momentum pair methods, the nuclear equations of state for pure neutron and symmetric nuclear matter are calculated with bare Argonne V4’ (AV4’) nucleon-nucleon (NN) interactions. The nuclear matter is described in a finite size of cubic box with finite magic mass numbers under periodic boundary condition. The unitary correlation operator method (UCOM) for central correlation is employed to treat the short-range repulsion in the NN interaction, and the two-particle two-hole (2p2h) excitations of nucleon pair with a large relative momentum, which is called high-momentum pair (HM), are further included. With the 2p2h configurations increasing, the total energy per particle of nuclear matter is well converged under this UCOM+HM framework. Moreover, the contributions of each Hamiltonian components to the total energy per particle are obtained as well. By comparing the results calculated with the present UCOM+HM and those with other microscopic many-body theories, the fairly consistent is found between these calculations.
        Speaker: Dr Niu Wan (Nanjing University)
      • 6:00 PM
        Improvement of Peak Hold Method for High Speed Nuclear Pulse Signal 1h
        - **Background:** In nuclear detection, researchers can extract nuclear information by analyzing the narrow pulse signal of the output of the nuclear detector. A scintillator detector which consisting of a scintillator and a photomultiplier tube is one of the most widely used ionizing radiation detectors. When the scintillator absorbs the gamma rays emitted by the radioactive elements, the detector outputs narrow pulse signals of different amplitudes, and the amplitude values of the narrow pulse signals correspond to the energy intensity of the gamma rays. - **Purpose:** The output of scintillator detector is usually the narrow pulse signal of ns-level.It is difficult for the general electronic system to directly and accurately acquire the amplitude information of the narrow pulse signal.The conventional voltage type peak hold circuit is prone to large overshoot and has a narrow bandwidth.Although the ordinary transconductance type peak hold circuit can effectively reduce the overshoot, it is difficult to simultaneously achieve rapid pulse shaping and long-term stable peak hold. Therefore, it is necessary to design a circuit that simultaneously achieves rapid pulse shaping and stable peak hold. - **Methods:** An improved peak hold circuit based on the output signal of the scintillator nuclear detector is designed to achieve peak hold of the ns-level high-speed nuclear pulse signal by double-stage peak hold circuit. Each stage of the peak hold circuit uses a transconductance op amp, which can effectively reduce the impact of overshoot on maintaining accuracy. The first stage peak hold circuit achieves a fast response to narrow pulse signals, and the second stage peak maintains the function of achieving a stable amplitude for a long time. - **Results:** The designed of double-stage transconductance peak hold circuit is suitable for processing high-speed narrow pulse signals output by nuclear detectors. The response time of this circuit is less than 20 ns, the amplitude error of peak hold is less than 2%, and the peak droop rate is less than 5 mV/us. The double-stage transconductance peak hold circuit has the advantages of fast response, high precision, good stability and wide bandwidth,which is suitable for processing ns-level high-speed narrow pulse signals of nuclear detector output.
        Speaker: Ms YUNFENG XIAO (Central China Normal University)
      • 6:00 PM
        J/$\psi$ production measurements in p+p and p+A collisions at $\sqrt{s_{NN}}$ = 200 GeV through the di-muon channel at STAR 1h
        Quarkonium production is an important tool to study the properties of the Quark-Gluon Plasma (QGP) formed in relativistic heavy-ion collisions. In particular, suppression of the J/$\psi$ meson production due to the color-screening effect was proposed as a direct evidence of the QGP formation. However, interpretation of the J/$\psi$ suppression in heavy-ion collisions requires knowledge of cold nuclear matter effects and will benefit from a better understanding of the J/$\psi$ production mechanism. By comparing J/$\psi$ production cross-section and polarization in p+p and p+Au collisions, the cold nuclear matter effects can be studied in detail. Moreover, J/$\psi$ polarization is sensitive to the J/$\psi$ production mechanism, and its measurement can help distinguish among different models. The STAR experiment at RHIC recorded large samples of p+p and p+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV for charmonium studies utilizing the trigger provided by the Muon Telescope Detector. In this talk, we will present the recent measurements of the J/$\psi$ production in p+p collisions. The results will be compared to model calculations. Furthermore, we will present measurements of the nuclear modification factor for J/$\psi$ over a broad kinematic range in p+Au collisions, to quantify the cold nuclear matter effects.
        Speaker: Zhen LIU (University of Science and Technology of China)
        Slides
      • 6:00 PM
        Local spin polarization in high energy heavy ion collisions 1h
        We revisit the azimuthal angle dependence of the local spin polarization of hyperons in heavy-ion collisions at 200 GeV in the framework of the (3+1)D viscous hydrodynamic model CLVisc. Two different initial conditions are considered in our simulation: the optical Glauber initial condition without initial orbital angular momentum and the AMPT initial condition with an initial orbital angular momentum. We find that the azimuthal angle dependence of the hyperon polarization strongly depends on the choice of the so-called spin chemical potential Ωµν. With Ωµν chosen to be proportional to the temperature vorticity, our simulation shows qualitatively coincidental results with the recent measurements at RHIC for both the longitudinal and transverse polarization. We argue that such a coincidence may be related to the fact that the temperature vorticity is approximately conserved in the hot quark-gluon matter.
        Speaker: Mr Hong-Zhong Wu (USTC)
      • 6:00 PM
        Measurement of the mass difference and the binding energy of the hypertriton and antihypertriton with the Heavy Flavor Tracker at RHIC-STAR 1h
        The Hyperon-Nucleon (YN) interactions play an important role in understanding the strong interaction. It is suggested that alternative YN couplings can be a possible solution to the recent observations of neutron star exceeding two solar masses, the so-called ``hyperon puzzle". A precise measurement of binding energies of hypertriton and antihypertriton can enrich our knowledge on YN interactions. On the other hand, the precise measurement of mass difference between hypertriton and antihypertriton can provide validation of CPT symmetry in hypernuclei sector and constraint on the parameters of SME (Standard Model Extension). In this talk, we will present the first precise measurement of mass difference between hypertriton and antihypertriton in heavy-ion collisions at STAR with the Heavy Flavor Tracker (HFT). Hypertritons and antihypertritons are reconstructed through both two-body ($^{3}He$ + $\pi^{-}$) and three-body ($p+d+\pi^{-}$) decay channels using the high-statistics data collected in 2014 and 2016 Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The measured masses will be used to extract the binding energies for hypertriton and antihypertriton. Physics implications on the understanding of YN interactions will be discussed.
        Speaker: Peng Liu (S)
      • 6:00 PM
        Measurements of open bottom production through multiple decay channels in Au+Au collisions at $\sqrt{s_{\rm NN}}=200$~GeV with STAR experiment 1h
        Yingjie Zhou for the STAR Collaboration Institute of Particle Physics, Central China Normal University, China Heavy quarks are predominantly produced at early stages of relativistic heavy-ion collisions before the creation of the deconfined QCD medium, known as the Quark-Gluon Plasma (QGP). Heavy quarks subsequently interact with the QGP throughout its whole evolution, and thus are suggested as an excellent probe to study the properties of the QGP. Observed suppression of high-${p}_\mathrm{T}$ electrons from decays of heavy-flavor hadrons in Au+Au collision with respect to p+p collisions has been interpreted as being due to energy loss of the heavy flavor quarks in the QGP. The energy loss is expected to be different for bottom and charm quarks because of their different masses. In this talk, we will present measurements of electrons, $D^0$ and $J/\Psi$ from open bottom hadron decays in Au+Au collisions at $\sqrt{s_{\rm NN}}=200$~GeV by the STAR experiment. These decay products are topologically identified using information from the Heavy Flavor Tracker, a silicon vertex detector installed at STAR during the period of 2014 - 2016. These results will be compared to those of open charm hadrons to study a mass dependence of the parton energy loss in the QGP at RHIC.
        Speaker: yingjie (for STAR collaboration) zhou (Central China Normal University)
      • 6:00 PM
        Meson spectrum in an unquenched quark model 1h
        The unquenched quark model for meson is explored in the present work. The quark-pair creation operator, which mix the two-quark and four-quark components, from 3P0 model is modified by considering effects of the created quark pair's energy and the separation between the created quark pair and the valence quark pair. All the wave functions needed are obtained by solving the corresponding Schrodinger equation with the help of the Gaussian expansion method. The results show that the unquenched quark model is convergent and some exotic states, for example X(3872) can be described well in the unquenched quark model.
        Speaker: Prof. Jialun Ping (Nanjing Normal University)
      • 6:00 PM
        Microscopic optical potentials for Li isotopes 1h
        The microscopic optical potentials for Li isotopes(A=6,7,8) without free parameter are obtained by folding the microscopic optical potentials of their internal nucleons with density distributions generated from corresponding internal wave functions. An isospin-dependent nucleon microscopic optical potential based on the Skyrme nucleon-nucleon effective interaction is used as the nucleon optical potential. Shell model and cluster model are employed respectively to construct the internal wave functions of Li isotopes(A=6,7,8) and derive their density distributions of internal nucleons. The Li microscopic optical potentials are used to calculate the elastic-scattering angular distributions and reaction cross sections. The results reproduce experimental data well and are comparable to those calculated by phenomenological optical model potentials in many cases.
        Speaker: Dr wendi Chen (Graduate School of China Academy of Engineering Physics)
      • 6:00 PM
        n+d反应截面的Faddeev-AGS方程计算 1h
        n+d 的反应截面(弹性散射和破裂反应)是重要的核反应数据。Faddeev-AGS方程是描述 n+d 反应的最好的理论工具。我们介绍利用 Faddeev-AGS 方程对 n+d 反应的计算及其结果。
        Speaker: Dr Danyang Pang (Beihang University)
      • 6:00 PM
        n+d反应截面的Faddeev-AGS方程计算 1h
        n+d 的反应截面(弹性散射和破裂反应)是重要的核反应数据。Faddeev-AGS方程是描述 n+d 反应的最好的理论工具。我们介绍利用 Faddeev-AGS 方程对 n+d 反应的计算及其结果。
        Speaker: Dr 丹阳 庞 (北京航空航天大学)
      • 6:00 PM
        Nuclear giant dipole resonance width as a potential probe of the in-medium nucleon-nucleon cross sections 1h
        The spreading width of nuclear giant dipole resonance in Pb208 is studied in the Boltzmann-Uehling-Uhlenbeck transport theory with a lattice Hamiltonian method. The obtained spreading width shows a strong dependence on the in-medium nucleon-nucleon elastic scattering cross sections, which suggests the spreading width of nuclear giant dipole resonance as a novel probe of the medium correction of the nucleon-nucleon elastic scattering cross sections. We then find that the experimental value of giant dipole resonance width of Pb208 measured at RCNP prefers a strong medium effects.
        Speaker: Rui Wang (Shanghai Institute of applied physics)
      • 6:00 PM
        Production of neutron-rich Rf isotopes by multinucleon transfer reactions based on 238U beam 1h
        The production of neutron-rich Rf isotopes in multinucleon transfer reactions is investigated using the dinuclear system model with GEMINI++ code. The reaction 238U + 252Cf is more advantageous to generate neutron-rich Rf isotopes than 238U + 249Bk and 238U + 248Cf, because 252Cf has a larger N/Z ratio and neutron number. The influence of incident angular momentum on the production cross sections in the 238U + 252Cf reaction is investigated. The cross sections of primary products become larger with increasing incident energy, while the final yields of the unknown isotopes at 1.1Vc are slightly larger than at 1.05Vc and 1.2Vc. Hence, 1.10Vc is a suitable incident energy in the 238U + 252Cf reaction to produce Rf isotopes. Four unknown Rf isotopes, 264Rf, 266Rf, 268Rf, and 269Rf, are synthesized in the 238U + 252Cf reaction with cross sections 97.2, 31.1, 0.61, and 0.04 nb, respectively. Considering the beam intensity and thickness of the target, the counts per day of those four unknown isotopes are 2724, 872, 17, and 1, respectively.
        Speaker: Dr Gen Zhang (Beijing Normal University)
      • 6:00 PM
        Quarkonia production in small systems with ALICE 1h
        In pp collisions at LHC energies, the production of heavy quarks proceeds dominantly from the hard scattering of two gluons. These quarks then hadronise in either open heavy-flavour hadrons or quarkonia (e.g. J/$\psi$, $\Upsilon$). The study of quarkonium production as a function of the charged-particle multiplicity, therefore, naturally links soft and hard processes that occur in the collision and allows one to study their interplay. While a linear increase of quarkonium production as a function of the charged-particle multiplicity can be reasonably well understood in the context of multi-parton interactions, the observation of deviations with respect to a linear increase requires a more detailed description of the collision and the inclusion of additional mechanisms such as collective effects, color reconnection or percolation. The ALICE detector at the LHC measures quarkonium production down to zero transverse momentum in two rapidity ranges: at mid-rapidity in the di-electron decay channel using the central barrel and at forward rapidity in the di-muon decay channel using the muon spectrometer. In this contribution, we will present the production of quarkonia (J/$\psi$, $\Upsilon$) as a function of the charged-particle multiplicity measured by ALICE in pp and p-Pb collisions. These results will be compared to the corresponding measurements performed for open heavy flavours, as well as to model calculations.
        Speaker: Ms Yanchun Ding (CCNU)
      • 6:00 PM
        Recent jet results in Heavy-Ion collisions at RHIC 1h
        Jet in heavy-ion collisions is considered as a self-generated tomographic probe to study the Quark-Gluon Plasma (QGP) created at the Relativistic Heavy Ion Collider, in BNL. Jet is quenched in the QGP relative to that in a vacuum, and this produces very striking evidence of the QGP. Recently, different new jet measurements have been performed both in the STAR and PHENIX experiments. This includes semi-inclusive jet measurement on direct-photon and hadron trigger recoil jet at top RHIC energy in Au+Au collisions, the di-jet imbalance between hardcore jets, and jet shape analysis. A perspective for the forward jet measurement in a heavy-ion context for the STAR forward upgrade will also be discussed.
        Speaker: Nihar Sahoo (Shandong University)
      • 6:00 PM
        Rescattering effect on the measurement of K* spin alignment in heavy-ion collisions with UrQMD 1h
        In non-central relativistic heavy ion collisions, the created matter possesses a large initial orbital angular momentum. Particles produced in the collisions could be polarized globally in the direction of the orbital angular momentum due to spin-orbit coupling. The measurement of vector mesons K* and $\phi$ can provide information of the large vorticity of the hot, dense medium created in non-central heavy-ion collisions. Due to short lifetime of K* which is comparable to the time between chemical freeze-out and kinetic freeze-out, the reconstructed K* suffers from the rescattering effect (A K* can not be reconstructed experimentally via the invariant mass method if the K* decays in the medium and one or more daughters is scattered in the medium). Because of the anisotropy of the medium in coordination space, the rescattering effect on K* could depend on $cos\theta^*$ thus result in non-uniform $cos\theta^*$ distribution for reconstructed K*. It could be a very important background for the study of global polarization via the K* spin alignment measurements in non-central heavy-ion collisions. In this talk, we will present the study of measurement of K* spin alignment in heavy-ion collisions using the UrQMD model. We use the history file to identify K* decays and select the reconstructable K*. The cos$cos\theta^*$ distribution is studied and the spin alignment parameter rho_00 is exacted and plot against transverse moment and centrality.
        Speaker: Ziyang Li (University of Science and Technology of China)
        Poster
      • 6:00 PM
        Search for the candidate chiral nuclei in the A~80 mass region 1h
        Spontaneous symmetry breaking is a fundamental concept in nature. As a many-body quantum system, the atomic nucleus carries a wealth of information on fundamental symmetries and symmetry breaking. As one example, chiral symmetry breaking in atomic nuclei has attracted considerable attention and intensive discussion since it was first predicted by Frauendorf and Meng [1]. They pointed out that, in the intrinsic frame of the rotating triaxial nucleus, the total angular momentum vector may lie outside the three principal planes, referred to as chiral geometry. The spontaneous chiral symmetry breaking in the laboratory framemay give rise to pairs of nearly degenerate ΔI = 1 bands with the same parity, i.e., chiral doublet bands. The present work performed a series of theoretical studies on nuclear chiral symmetry breaking in the A~80 mass region. Following the reports of candidate chiral doublet bands observed in 78,80,82Br[2-4], chirality in the Rb, Kr, Br, and As isotopes is investigated for the first time by using adiabatic and configuration-fixed constrained triaxial relativistic mean field (RMF) theory[5-7]. The existence of the chiral doublet bands, as well as multiple chiral doublet bands in the A~80 mass region is demonstrated. Refrences: 1. S. Frauendorf and J. Meng, Nucl. Phys. A617, 131 (1997)。 2. S. Y. Wang et al., Phys. Lett. B 703, 40 (2011). 3. C. Liu et al., Phys. Rev. Lett. 116, 112501 (2016). 4. C. Liu et al., under review. 5. J. Meng, J. Peng, S. Q. Zhang, and S.-G. Zhou, Phys. Rev. C 73, 037303 (2006). 6. J. Peng, H. Sagawa, S. Q. Zhang, J. M. Yao, Y. Zhang, and J. Meng, Phys. Rev. C 77, 024309 (2008). 7. J. Li, S. Q. Zhang, and J. Meng, Phys. Rev. C 83, 037301 (2011).
        Speaker: Dr Chen Liu (Shandong University)
      • 6:00 PM
        Study of nuclear modification factors of (anti-)hadrons and light (anti-)nuclei in Pb-Pb collisions at √sNN = 2.76 TeV 1h
        The nuclear modification factors ($R_{AA}$) of $\pi^{\pm}, p(\bar p)$, and $d(\bar d)$ with $|y|<0.5, p<6.0$ GeV/c in peripheral (40-60%) and central (0-10%) lead-lead collisions at $\sqrt {s_{NN}}$ =2.76 TeV have been studied using the parton and hadron cascade ( PACIAE) model plus the dynamically constrained phase-space coalescence ( DCPC ) model. It is found that the distribution of $R_{AA}$ of light (anti-)nuclei $d$ is similar to that of hadrons ($\pi, p$), and the distribution of anti-particles is the same as that of particles. The suppression of high transverse momentum particles strongly depends on event centrality and mass of the particles, $i.e$, the central collision is more suppressed than the peripheral collision. Besides, the yield ratios, double ratios $R^D_{AA}$ of ($\bar d$ to $\bar p$, $\bar p$ to $\pi^-$, $d$ to $p$, $p$ to $\pi^+$), and the coalescence parameter $B_2$ for ($d, \bar d$) in pp, central and peripheral $Pb-Pb$ collisions are discussed, respectively. It is observed that the yield ratios and $R^D_{AA}$ of $\bar d$ to $\bar p$ and $\bar p$ to $\pi^-$ are also the same with the corresponding values of $d$ to $p$ and $p$ to $\pi^+$ in three different collision systems, respectively, suggesting that the suppressions of matter ($\pi^{+}, p, d$) and the corresponding antimatter ($\pi^{-},\bar{p},\bar{d}$) has the same character and performance. Our results are comparable to those of experimental data at $p_{T}<3.0$ GeV/c.
        Speaker: Mr Zhilei She (China University of Geosciences(Wuhan))
        Poster
      • 6:00 PM
        Study of reaction mechanisms induced by exotic nuclei and weakly bound nuclei at energies around Coulomb barrier as well as related nuclear structure 1h
        G. X. Zhang1, S. P. Hu2, G. L. Zhang1, H. Q. Zhang3, C. J. Lin3, J. Lubian4, W. W. Qu5, Z. Huang1, M. L. Wang1, Y. J. Yao1, X. D. Su1, X. G. Wu3, C. B. Li3, L. Yang3, N. R. Ma3, D. Testov6, D. Mengoni6, J. J. Valiente-Dobon7, A. Goasduff6, D. Bazzazzo6, H. B. Sun2, Y. Zheng3 1 School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China 2 School of Physics and Energy, Shenzhen University, Shenzhen 518060, China 3 China Institute of Atomic Energy, Beijing 102413, China 4 Instituto de Física, Universidade Federal Fluminense, Avenida Litorânea s/n, Gragoatá, Niterói, Rio de Janeiro 24210-340, Brazil 5 State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, China 6 Dipartimento di Fisica and INFN, Sezione di Padova, I-35131 Padova, Italy 7 INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy In the reactions induced by exotic and weakly bound nuclei at energies around coulomb barrier, breakup is an important reaction channel. It can provide rich information for nuclear reaction mechanisms and nuclear structure at energies around coulomb barrier. For breakup researches, the elastic scattering and fusion were used. The elastic scattering angular distributions were measured for 50 and 59 MeV 17F radioactive ion beam on a 89Y target. The experimental data were analyzed by means of the optical model with the double-folding Sao Paulo potential for both real and imaginary parts. The theoretical calculations reproduced the experimental data reasonably well. It is shown that the method of the data analysis is correct. Continuum-Discretized Coupled-Channels (CDCC) calculations were performed to consider the breakup coupling effect. It is found that the experimental data show the Coulomb rainbow peak and that the effect of the coupling to the continuum states is not very significant, producing only a small hindrance of the Coulomb rainbow peak and a very small enhancement of the elastic scattering angular distribution at backward angles, suggesting that the multipole response of the neutron halo projectiles is stronger than that of the proton halo systems. The beam intensities of stable weakly bound nuclei such as 6,7Li and 9Be, which have significant breakup probability, are orders of magnitude higher. Precise fusion measurements induced by these nuclei have already been performed. However, the conclusion of reaction dynamics was not clear and has the contradiction. In order to have a proper understanding of the influence of breakup and transfer of weakly bound projectiles on the fusion process, the 6Li+89Y and 6Li+209Bi experiments were performed on Galileo array in combination with Si-ball EUCLIDES at Legnaro National Laboratory (LNL) in Italy. Using the coincidence by the charged particles and γ-rays, the different reaction channels can be clearly identified. Also the new energy levels of some nuclei were founded, and then the nuclear structure is explored.
        Speaker: Dr Gaolong Zhang (BUAA)
      • 6:00 PM
        Temperature Fluctuation and the Specific Heat in Au+Au Collisions at $\sqrt{s_{NN}}$ = 7.7 $-$ 200 GeV 1h
        Specific heat is a thermodynamic quantity that characterizes the equation of state of the system. For a system undergoing phase transition, the specific heat, $C_{V}$, is expected to diverge at the critical point. Temperature fluctuation of the system provides an estimation of $C_{V}$. The specific heat can be extracted from event-by-event temperature fluctuation. Thus the variation of thermal fluctuations with temperature can be effectively used to probe the QCD phase transition and QCD critical point. In this talk, we will present the energy dependence of specific heat and temperature fluctuations of the QCD matter created in Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7, 11.5, 19.6, 39, 62.4 and 200 GeV from STAR and compared with model calculations.
        Speaker: Ms Xiujun Li (USTC)
        Poster
      • 6:00 PM
        The effect of the positive Q-value neutron transfers on near-barrier heavy-ion fusion 1h
        In near-barrier fusion reactions with heavy-ions, the coupling effect of the positive Q-value neutron transfers (PQNT) is still a complex and unsolved problem. For studying this effect, the fusion excitation functions of the typical systems, such as 32S+90,94,96Zr, were measured by using an electrostatic deflector setup at CIAE. In this talk, the recent experimental results measured at CIAE will be reviewed, with special emphasis on the effect of the positive Q-value neutron stripping channels of 18O+50Cr,58Ni,74Ge. Additionally, considering the current inconsistent experimental data and theoretical analysis, the concept of residual enhancement (RE) that mainly aims for reducing the additional uncertainties was proposed to extract a reliable quantitative PQNT effect. More recent experimental studies for reaction mechanism will be also presented in this talk.
        Speaker: Dr Huiming JIA (China Institute of Atomic Energy)
      • 6:00 PM
        The evolution of Information entropy in Relativistic Heavy-Ion Collisions 1h
        Shannon information entropy provides an effective tool to study the evolution process in relativistic heavy-ion collisions. Three types of entropy production were studied in relativistic nuclear collisions by using a multiphase transport mode. The linear growth stage of Thermodynamic entropy seems to indicate the transition of the collision system from quark-gluon plasma to hadronic gas. The inflection point of Multiplicity entropy is probably the appearance of phase transition point. A conclusion can be drawn by the way of adding up various information entropies that a more complete description of information entropy can obtain a smoother evolution curve of information entropy produced in relativistic nuclear collisions.
        Speakers: Prof. Gang Chen (Physical Department, China University of Geosciences) , Mr 飞 李 (Physical Department, China University of Geosicences (WuHan))
      • 6:00 PM
        The fragment effects on shear viscosity and liquid-gas phase transition in nuclear plasma 1h
        We simulated nuclear matter in a periodic box with an improved quantum molecular dynamic (ImQMD) model and extracted shear viscosity using the Gaussian thermostated SLLOD algorithm. As the mean filed is switched on, fragments forming at low density and low temperature, shear viscosity is declined. And also a slope of the shear viscosity, the ratio of the number of free nucleons to that of the intermediate mass fragments and the mean mass of the largest fragments as functions of temperature are discussed. We found, in all cases, turning points lying in a critical temperature regions around T∼8 MeV, which can be signals of the liquid-gas phase transition.
        Speaker: Dr Xian-Gai Deng (Fudan University)
        Poster
      • 6:00 PM
        The properties of ZnS thin films prepared by low-temperature sulfidation 1h
        Zinc sulfide (ZnS) is one of the first semiconductors discovered. It has the greatest band gap among the II-VI compound semiconducting materials. With the good optoelectronic properties, ZnS has been widely used in many optoelectronic devices. The preparation and physics of good quality ZnS thin films has always been one of the focuses of the research on the wide band gap material. In the article, ZnS thin films were prepared on the glass substrates by annealing Zn thin films in sulfur vapor and Ar gas, which were deposited by magnetron sputtering from a zinc target. The microstructure defects, crystallizations, surface morphology and optical properties of the samples were analyzed by PAT(positron annihilation technique), XRD(X-ray diffraction), SEM(scanning electron microscopy) and UV-VIS spectrophotometer. The resultant ZnS thin films exhibits a good optical transmittance and the better S/Zn atomic ratio compared with those samples prepared by sulfidation in the vacuum-sealed quartz-glass ampoules.
        Speakers: rengang zhang (Wuhan University of science and technology) , xingzhong cao (Institute of High Energy Physics, CAS))
      • 6:00 PM
        The ratio of the neutron yield to the proton yield in 12C(d; n)13N and 12C(d; p)13C from 0.6 MeV to 3 MeV 1h
        The neutron yield and the proton one in $^{12}$C(d,n)$^{13}$N and $^{12}C(d,p)^{13}$C have been measured respectively from 0.6 MeV to 3 MeV using a 4-MeV electro static accelerator to generate deuteron beam to bombard the thick carbon target. The neutrons are detected at 0 degree, 24 degree, 48 degree and the protons at 135 degree in the lab frame. The ratios of the neutron yield to the proton one have been calculated and can be used as an effective probe to pin down the resonances. The resonances are found at 1.4 MeV, 1.7 MeV, 2.5 MeV in $^{12}C(d,p)^{13}$C and at 1.6 MeV, 2.7 MeV in $^{12}$C(d,n)$^{13}$N. This method provides a way to reduce the systematic uncertainty and helps to confirm more resonances in compound nuclei.
        Speakers: Mr Wujie Li (Shanghai Institute of Applied Physics, Chinese Academy of Sciences) , Prof. Yugang Ma (Shanghai Institute of Applied Physics, Chinese Academy of Sciences)
      • 6:00 PM
        The study of screened electrostatic effect in nuclear decay 1h
        1、The theoretical models of proton emission and α decay 2、The Gamow-like model and screened electrostatic effect 3、Our works 4、Summary
        Speaker: 小华 李 (å)
      • 6:00 PM
        The use of a new method - ToF-SIMS in the characterization of fusion materials and HLW glasses 1h
        Abstract: Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a very important tool in the characterization of various materials, but the use of ToF-SIMS in nuclear field is still not fully developed. In this work, we introduce several studies focusing on the spectra, depth profiles and elemental images of the nuclear fusion materials using ToF-SIMS. In the first part, Hydrogen (H) depth profiles in tungsten (W), which is an important plasma facing material (PFM) in fusion reactors, were ideally provided by ToF-SIMS. The result indicates an obvious increase of H with an implantation fluence of 1×1020 H+/cm2. Moreover, H shows a totally different behavior in the He+ and Au+-damaged samples. The distribution is greatly dependent on the implanting range of the damaged ions. In the second part, deuterium (D), W and titanium (Ti) depth profiles were mainly concerned in zirconium deuteride (ZrDx) layers. However, due to the extremely low concentration, W was not detected by ToF-SIMS. On the other hand, nuclear reaction analysis (NRA) and elastic recoil detection analysis (ERDA) could detect obvious W signals on the surface. These two methods were also used for the quantitative analysis. The third part is the study of light elements in the radioactive wastes. Elemental imaging was provided on irradiated glass-ceramics. The result indicates an obvious migration of important ions such as boron (B), sodium (Na), aluminum (Al) and titanium (Ti) with good spatial resolutions. Above studies are very fundamental trials but show great potentials of ToF-SIMS in the study of nuclear field. ToF-SIMS has its disadvantages but can be well used as a main or supplemental tool with other techniques. Additionally, we have observed an strange change of the sputtering rates during the analysis on a carbon (C) ion-implanted SiC sample. The reasons were also discussed here.
        Speaker: 建东 张 (Nanjing University of Aeronautics and Astronautics)
      • 6:00 PM
        Thermal propertities of light-flavor scalar resonances at finite temperatures 1h
        In this talk, I will present our recent study on the thermal properties of the lowest multiplet of the QCD light-flavor scalar resonances, including the f0(500)/σ, K∗0(700)/κ, f0(980) and a0(980), in the framework of unitarized U(3) chiral perturbation theory.
        Speaker: Prof. Zhi-Hui Guo (Hebei Normal University)
      • 6:00 PM
        伽玛射线康普顿散射谱影响因素的研究 1h
        伽玛射线康普顿散射谱与其入射能量、注量率、散射体的物质成分以及几何布置等因素相关,研究伽玛射线在物质中的散射效应,对伽玛射线屏蔽及其安全防护等具有重要的意义。为研究伽玛射线散射谱的影响因素,使用Cs-137放射源及闪烁体探测器,在工作状态一定的情况下,分析反散射峰的计数率与反散射物质的原子序数、厚度及距离的相关性。
        Speaker: Mr 厚军 何 (东华理工大学)
      • 6:00 PM
        先进外中子源驱动核能系统CLEAR-A中子学初步设计分析 1h
        核能作为一种清洁能源,在全球能源结构中需要发挥越来越重要的作用。然而,核能的大规模发展也面临一些问题,如核安全问题、核废料处置、核燃料短缺等变得日益突出。因此,中国科学院核能安全技术研究所提出了一种基于铅合金冷却反应堆的新型外中子源驱动核能系统(CLEAR-A,Advanced External Neutron Source Driven Nuclear Energy System ),通过外源高能中子与低品质核燃料发生反应,实现安全、高效能量输出和核废料嬗变处理。 本文针对CLEAR-A系统开展了堆芯中子学初步设计与分析,利用中子输运设计与安全评价软件系统“超级蒙卡”(SuperMC)和混合评价核数据库(HENDL)为研究手段,开展燃料类型,燃料富集度,冷却剂类型和反射层材料类型等堆芯关键参数对堆芯性能影响分析,筛选出具有最优性能的次临界反应堆堆芯方案。在此基础上,开展外中子源初始位置和移动速度等关键外中子源参数对次临界反应堆堆芯增殖燃烧波的影响规律研究,寻求与其匹配的最佳外中子源初始位置与移动速率方案。
        Speaker: Dr Xiaoliang Zou (Institute of Nuclear Energy Safety Technology, CAS)
      • 6:00 PM
        全吸收型BaF2探测装置中子屏蔽准直体与中子吸收体的研究 1h
        中子俘获反应截面数据在核天体物理研究、核反应堆设计与核能开发利用中具有非常重要的意义。中国原子能科学研究院已经建造完成了我国第一套的全吸收型BaF2探测装置(Gamma Total Absorption Facility, GTAF),采用瞬发γ测量法,精确测量中子俘获反应截面。中子源是利用HI-13串列加速器产生的脉冲化质子束,通过7Li(p, n)7Be反应建立的。为了有效降低周围环境材料和探测器上产生的散射中子本底,约束中子束流的形状,设计了中子屏蔽准直体。使用MCNP 模拟程序模拟计算了中子和γ射线在几种主要的屏蔽材料中的输运过程,并通过模拟计算确定了屏蔽准直体的加工材料和几何尺寸。为了吸收待测样品产生的散射中子,需要在探测器球壳内部放置中子吸收体,同时吸收体材料还要尽可能的减少对γ能谱的影响。通过MCNP的模拟结果得到了比较理想的设计方案,满足在线开展中子俘获反应截面测量的实验要求。
        Speaker: Dr Qiwei Zhang (China Institute of Atomic Energy)
      • 6:00 PM
        利用TALYS和GEANT4研究中高能中子与铁作用的次级中子双微分截面 1h
        在ADS系统的优化设计中,计算程序结合可靠的核反应理论模型对中高能中子诱发核反应进行计算具有重要的意义。同时,铁作为一种重要的结构材料,在核反应堆、加速器等核设施中被大量使用。本工作利用TALYS程序和GEANT4程序结合不同的核反应理论模型计算了中高能中子轰击薄铁靶在不同出射角度的次级中子双微分截面,并与现有实验数据进行了对比。总体来看,TALYS程序和GEANT4程序结合可靠的核反应理论模型的计算结果可以较好地再现实验数据。
        Speaker: Mr 丙岩 刘 (中国科学院近代物理研究所)
      • 6:00 PM
        双幻核132Sn附近丰中子同位素核结构性质的壳模型分析 1h
        双幻核132Sn附近丰中子同位素的研究是核物理与核天体物理共同关注的热点,对其核结构性质的分析为研究极端丰中子核结构,寻找滴线区的新物理奠定了良好的基础。目前已经可以通过几种不同的方法来确立132Sn 的双幻属性,例如借助直接测量质量的彭宁阱[1], 或者通过观测132Sn 邻近奇质量同位素核的单粒子态[2], 也可以利用Pd(钯)丰中子同位素低激发态的集体演化[3]。在核素128Pd 、130Cd(镉)中发现的辛弱结构的同核异能态也是N=82 壳闭合的重要依据[4-6]。 随着实验观测的不断深入,对理论分析的需求也在不断增加,然而132Sn 附近丰中子同位素的研究目前还面临着许多困难与挑战。为率先从理论上突破132Sn附近丰中子同位素实验观测与理论研究互相制约发展的瓶颈,并适应核物理实验装置快速发展的形势,本课题将利用EPQQM (the extended pairing plus quadrupole-quadrupole forces accompa-nied by the monopole corrections) 模型[7-8],对132Sn附近的丰中子同位素展开理论研究。EPQQM模型不仅具有建模优势,还附加单极修正的功能,可以很好地研究单极相互作用对核结构性质的影响。 [1] A. Kankainen, J. Hakala, T. Eronen et al., Phys. Rev. C87, 024307(2013) [2] K. L. Jones, A. S. Adekola, D. W. Bardayan et al., Nature(London)465, 454-457(2010). [3] H. Wang, N. Aoi, S. Takeuchi et al., Phys. Rev. C88, 054318(2013). [4] A. Jungclaus, L. Cáceres, M. Gόrska et al., Phys. Rev. Lett. 99, 132501(2007). [5] H. Watanabe, G. Lorusso, S. Nishimura et al., Phys. Rev. Lett. 111, 152501(2013). [6] H. K. Wang, K. Kaneko, and Y. Sun, Phys. Rev. C89, 064311 (2014). [7] M. Hasegawa, K. Kaneko, and S. Tazaki, Nucl. Phys. A688, 765(2001). [8] K. Kaneko, Y. Sun, T. Mizusaki, and M. Hasegawa, Phys. Rev. C83, 014320(2011)
        Speaker: 韩奎 王 (N)
      • 6:00 PM
        同位旋非对称核物质的$\Delta$截面的研究 1h
        近十年来,对于FOPI 的发表的束流能量为0.4-1.2 GeV的Au+Au碰撞产生的pion产额以及$\pi^-/\pi^+$ 之比的实验数据的理论分析表明:目前利用$\pi^-/\pi^+$的数据结合输运模型比较给出的对称能约束存在很大的分歧和争议。这促使人们从实验和理论两个方面再次进行深入的研究和探索。理论方面,则需要进一步的理解同位旋相关的输运模型中$\pi$产生的各个环节,如介质中 $\Delta$、 $\pi$的产生和传播等问题,以为将来可靠确定对称能奠定基础。在这项工作中,我们在单玻色子交换模型中引入了$\Delta$自由度,并且考虑了同位旋矢量介子,如$\rho$、$\delta$和$\pi$的贡献,以其更合理的描写同位旋非对称核物质。基于此模型,我们研究了同位旋非对称核物质中$\Delta$产生截面,比如同位旋依赖的$\Delta$产生的能量阈值对于非对称核物质的介质中$NN\rightarrow N\Delta$的散射截面的影响。结果表明,截面介质修正因子 $R=\sigma_{NN\rightarrow N\Delta}^* / \sigma_{NN\rightarrow N\Delta}^{\text{free}}$,在考虑了同位旋依赖的$\Delta$产生的能量阈值后,介质修正因子的同位旋效应变弱。但是,R在阈值附近还可以观察到同位旋区分的效应。但是随着束流能量的增加,这种劈裂的幅度会变小。同时,我们分析了非对称核物质介质中$NN\rightarrow N\Delta$的散射截面和微分散射截面与状态方程软硬的关系。对于散射截面的介质修正因子R 而言,我们的结果显示有效质量越大(对称能的斜率越大),介质的修正效应越小。 The symmetry energy at suprasaturation density is very important for understanding the nuclear astrophysics. In last couple decades, there are widely differences of the constraint of symmetry energy at suprasaturation density by comparing the $\pi^-/\pi^+$ ratio data from the FOPI Collaboration with calculations from transport models. It has stimulated both experimental and theoretical works to deeply understand the divergence. On the side of theory, one also need to deeply understand mechanism of the pion production and propagation, i.e., the in-medium $\Delta$ production, pion propagation, which are the key in transport models for describing the pion production in the simulation of heavy ion collisions. In this work, we study the $\Delta$ related inelastic scattering in isospin asymmetric nuclear matter in frame work of the one-boson exchange model. $\Delta$ and isovector mesons, i.e., $\rho$、$\delta$ and $\pi$, are included in order to reasonable describing the isospin asymmetric nuclear matter. Based on this model, we do the calculation of in-medium $\Delta$ production scattering in isospin asymmetric nuclear matter. Our results further confirm the dependence of medium correction factor, $R=\sigma_{ NN\rightarrow N\Delta}^*/\sigma_{NN\rightarrow N\Delta}^{\text{free}}$, on the charge state of $NN\rightarrow N\Delta$ especially around the threshold energy, but the isospin splitting of medium correction factor $R$ becomes weak at high beam energies. Secondly, we study the correlation between the in-medium $NN\rightarrow N\Delta$ cross section and the density dependence of the symmetry energy. By analyzing the selected effective Lagrangian parameters, our results show that the larger effective mass is, the weaker medium correction is. Thirdly, we analyze the dependence of M-matrix for $N\Delta\rightarrow NN$ on $\Delta$ mass, and give the precise calculation of $N\Delta\rightarrow NN$ cross section.
        Speaker: 莹 崔 (China Institute of Atomic Energy)
      • 6:00 PM
        基于CSRe开展低动量转移反应研究 1h
        轻离子诱发的低动量转移反应在核结构和核天体物理研究中起着重要的作用。基于兰州重离子冷却储存环,利用气体内靶,可以解决放射性束线上开展相关反应时低动量粒子的探测问题,使得轻离子诱发的低动量转移反应研究成为可能。近年来,为了研发谱仪,依托兰州重离子冷却储存环,研发了超高真空适用耐高温烘烤的硅条探测系统,开展了CSRe上首次质子弹性散射诱发的58Ni稳定核素的低动量转移反应实验。利用实验数据,开展了光学势的相关研究,提取了核物质密度分布,展示了兰州重离子冷却储存环加速器开展轻离子诱发的低动量转移反应的能力。
        Speaker: Dr 小林 涂 (中科院近代物理研究所)
      • 6:00 PM
        基于强度关联测量重子共振态时空性质 1h
        基于全同粒子间强度关联(HBT效应)测量QCD非微扰能区超短寿命重子共振态时空性质依然是一个挑战,这是因为目前还没有适用于低能区低末态粒子数粒子关联效应的有效观测方法。本工作尝试用HBT关联测量重子共振态$\Delta$(1232)的尺寸,实验数据来自于日本东北大学电子光理学研究中心开展的FOREST实验中的光生反应$\gamma p \to p \pi^0 \pi^0$实验结果(入射光子能量约为$1-1.15$ GeV)。为此开发了一种适用于低能区低末态粒子数HBT观测用的事件混合方法,通过引入额外的限制条件来抑制非强度关联效应及能量动量守恒带来的干扰。同时也建立了从$\gamma p \to \Delta \pi^0 \to p \pi^0 \pi^0$反应中末态粒子$\pi^0 \pi^0$关联效应中提取$\Delta$共振态半径信息的观测模型。目前已得到$\pi^0 \pi^0$强度关联的实验结果,并初步得到$\pi^0 \pi^0$出射区的高斯半径,对其它反应道的影响及系统误差的评估还在进行中。
        Speaker: Dr Qinghua He (Nanjing University of Aeronautics and Astronautics)
      • 6:00 PM
        基于非拓扑孤立子模型证明夸克禁闭的计算模拟 1h
        于昂扬 Normal University, Beijing, China 自1964年夸克模型提出以来,寻找自由夸克的实验工作尚无结果。量子色动力学理论目前也还无法直接证明夸克禁闭的存在,夸克禁闭问题时至今日仍然是当代物理学的前沿难题。非拓扑孤立子模型在描写强子静态性质方面取得了极大的成功。[1]该模型认为在强子外部夸克的质量远远大于强子的质量,这样就使得在强子外部产生一个夸克要比在强子内部产生一个夸克需要多得多的能量,这就提供了一种夸克禁闭的机制。[2]本工作从该模型出发,得到了孤立子解,计算结果显示:在强子内部夸克质量为零(m=O);而在强子边界之外,夸克的质量远远大于强子内部夸克的质量,因此,这就自然地导致了夸克禁闭的发生。 参考文献: [1] R. Goldflam and L. Wilets, Phys. Rev. D, 1982,25:1951. [2] Ma Wei-Xing et al., HEP & NP, 2003,27(2):127-129.
        Speaker: 昂扬 于 (Normal University, Beijing, China)
      • 6:00 PM
        奇奇核$^{74}$Br中可能存在的手征、摇摆激发带的实验研究 1h
        在A~80质量区的奇奇核$^{78,80,82}$Br中已经观测到了手征双带或多重手征带 [1,2,3],这证明这个区域的原子核普遍存在三轴形变。具有三轴形变的原子核的另外一个特征是存在摇摆激发带 [4,5,6],但是目前还没有实验发现手征带和摇摆激发共存的现象。此外这个区域的$^{73,78}$Br还观测到了正负宇称带间的八极关联效应 [7,1]。基于A~80质量区这些已经观测到或还未观测到但可能存在的丰富的原子核形状的相关现象,我们对这个区域的奇奇核$^{74}$Br开展了实验研究。 我们在南非iThemba实验室利用$^{58}$Ni($^{19}$F,2pn)$^{74}$Br反应开展了$^{74}$Br高自旋态的在束γ谱学实验。实验获得了约$3\times 10 ^9$个二重符合事件以及$4\times 10^8$个三重及以上符合事件。利用当前的实验数据,我们扩展了$^{74}$Br的能级纲图,目前将最高自旋了推高到了18$^+$,并观测到了13条转动带。通过对能谱、角分布、线性极化、能级寿命、约化电磁跃迁几率以及跃迁混合比的分析,我们认为$^{74}$Br中可能存在手征、摇摆激发、手征-赝自旋多重带[8]以及八极关联效应的共存。进一步的理论分析还在进行中。 参考文献: 【1】C. Liu et al., Phys. Rev. Lett. 116, 112501 (2016). 【2】S. Y. Wang et al., Phys. Lett. B 703, 40 (2011). 【3】C.Liu et al., under review. 【4】S.W. Ødegård et al., Phys. Rev. Lett. 86, 5866 (2001). 【5】S. Frauendorf et al., Phys. Rev. C 89, 014322(2014). 【6】Ikuko Hamamoto Phys. Rev. C 65, 044305 (2002). 【7】S. Bhattacharya et al., Phys. Rev. C 100, 014315(2019). 【8】Hui. Jia et al., J. Phys. G: Nucl. Part. Phys. 46, 035102 (2019).
        Speaker: 睿巨 郭 (山东大学(威海))
      • 6:00 PM
        快中子与$^{208}$Pb反应理论计算 1h
        本工作完成了快中子与$^{208}$Pb反应的理论计算。对于双幻数核$^{208}$Pb采用了EMPIRE3.2程序结合最新发展的同时适用于散射态和单粒子束缚态计算的球形色散光学势。此光学势可同时实现中子与$^{208}$Pb的散射数据计算,并利用其实部作为壳模型势给出对单粒子束缚能级的拟合。计算中,应用DWBA方法计算非弹性散射直接部分,激子模型计算预平衡机制,带宽度涨落的Hauser-Feshbach理论计算复合核发射,同时考察多种能级密度模型的影响。理论计算结果与各类实验数据进行了比对分析。
        Speaker: Ms Wenqing Du (Graduate School of China Academy of Engineering Physics)
      • 6:00 PM
        月球表面五种典型岩石的质子反应截面的不同计算方法对比 1h
        在研究月表质子诱发伽马辐射场中,质子反应截面是关键参数之一。其中R.K.Tripathi公式可以准确的计算单一核素的质子反应截面,但是对于混合物并没有给出明确的计算方法。本文采用三种方法不同的方法对R.K.Tripathi模型进行修正,将其应用于计算月表典型岩石的质子反应截面,并与Geant4模拟计算结果进行对比。结果表明,由均方根原子序数法,平均原子序数法,截面混合法得到的50-100MeV质子反应截面与Geant4模拟结果均有较好的符合,均方根原子序数法误差为5.61%-14.7%,平均原子序数法误差为1.39%-7.29%,截面混合法误差为2.69%-6.78%。其中在50-80MeV时使用平均原子序数法修正效果较好,而在80-100MeV截面混合法修正效果较好。
        Speaker: Mr Weicheng Li (ECUT)
      • 6:00 PM
        核子有效质量劈裂对重离子碰撞中椭圆流的影响 1h
        在核介质中核子的有效质量随核介质密度、动量及同位旋的变化情况是人们关心的话题。重离子碰撞可以用来研究核介质中核子的有效质量。本报告在极端相对论量子分子动力学(UrQMD)模型中引入了同位旋依赖的动量相关势,研究了入射能量为每核子0.09 GeV到1.5 GeV的金金碰撞中的集体流。计算结果能够很好的再现最新的FOPI合作组的关于质子的椭圆流随入射能量变化的实验数据。同时发现随着入射能量的增高,核子有效质量的劈裂(中子有效质量和质子有效质量之差)对于质子中子的椭圆流差的影响逐渐减小。相比于对称能的影响,核子有效质量劈裂对于质子中子的椭圆流差的影响较小。
        Speaker: Mr LuYao Tong (School of Science, Huzhou Teachers College, Huzhou 313000, China)
      • 6:00 PM
        用R-矩阵理论系统分析核子-核子碰撞-(NP,NN和PP) 1h
        到目前为止,关于核子-核子碰撞已经做了大量的实验与理论分析工作,不过在低能区域(小于50 MeV),如果将理论分析值与实验数据相比,差别还是很大的。相对较准确的是ENDF-VIII的P(n,n)P评价值,它是美国人用R-矩阵理论分析(EDA)得到的,不过在最关键的14 MeV 处,理论分析值与实验数据的差别还是很大。关于N(n,n)N,美国人是将用微观光学势分析得到的结果输入R-矩阵理论分析(EDA)得到的,具体细节没有发表。美国人也用R-矩阵理论分析(EDA)分析了P(p,p)P实验数据,具体细节也没有发表。 关于中子-中子碰撞截面,由于难以得到中子靶,不可能进行实际测量,目前只有一个用间接测量得到的热中子散射长度。关于质子-质子碰撞截面(去除长程库仑作用),在输运理论计算中有重要应用价值,不过在小于50 MeV区域还没有可靠准确的评价值。我们用约化R-矩阵理论程序-RAC系统地分析核子-核子碰撞-(NP,NN和PP)实验数据(能量小于60 MeV区域),以得到中子-中子散射截面评价值和质子-质子散射截面评价值。在评价过程中涉及到许多理论问题需要研究,比如说如何得到N(n,n)N的微分截面,如何处理库仑位罍区域的破坏性干涉。
        Speaker: 强华 吴 (清华大学)
      • 6:00 PM
        超强激光极端条件下核物理研究 1h
        随着激光技术的进步,激光强度在飞速提高。近年来,利用高强度激光诱发的核事件正逐步被深入研究和探索,从而诞生了一门新的学科----激光核物理。在超强激光光场所产生的新的极端环境,有望用来研究常规实验手段无法企及的核物理相关基础和应用问题。如:模拟大爆炸环境,研究等离子体条件下核反应;反应堆废料相关核素的嬗变;激光生成医用超短寿命同位素;以及产生伽马激光等等。本报告将对激光核物理现状进行简单综述,并介绍本实验组近期开展的相关工作。包括利用“激光等离子体对撞”的方法,研究低能核天体相关核反应,D+D and D+Li7等. 首次在等离子体环境下测量了D+Li7的S-factor. 此外将介绍利用激光产生同质异能素,成功利用激光库伦爆炸法,实现了纳米颗粒中Kr83的同质异能态产生。从而为进一步探索利用强激光产生伽马激光的新可能方法。 1. X.P.Zhang et al., Phys. Rev. C 96(2017)055801. 2. C. Fu, et al., Sci. Rep. 6(2015)27363. 3. X. P. Zhang et al., Rev. Sci. Instr. 89(2018)023505,
        Speaker: 长波 符 (复旦大学现代物理研究所)
      • 6:00 PM
        随机两体系综下非集体转动行为的鲁棒性 1h
        随机两体相互作用理论是研究“复杂原子核中简单规则的起源问题”的重要途径。过去许多研究工作聚焦于随机相互作用下偶偶核基态零自旋正宇称占优现象,而关于随机相互作用原子核基带在非正规序情况下的低激发态方面研究很少。通过研究非正规序基带的随机两体系综低激发态讨论随即相互作用下的原子核转动行为的鲁棒性,主要包括:研究偶偶核非零自旋基态下低激发态统计性质,包括基带能级次序、能级间隔分布、集体运动模式以及电磁性质,分析其与剩余相互作用的关联;(2)研究真实原子核在随机微扰下非集体转动特性和电磁性质的鲁棒性。
        Speaker: Mr JiaJie Shen (Shanghai Maritime University)
    • 7:00 PM 8:00 PM
      第十三届理事会全体理事会 科学会堂202

      科学会堂202

      华中师范大学

      武汉
    • 8:30 AM 10:10 AM
      S1: 核结构 科学会堂201

      科学会堂201

      华中师范大学

      武汉
      Conveners: Prof. 杰 孟 (北京大学) , Mr 立升 耿 (Beihang University)
      • 8:30 AM
        原子核单粒子共振态及奇特性质的研究 20m
        共振是自然界普遍存在的有趣现象。在核物理领域,存在许多奇特现象,共振在其中扮演着重要角色。本报告介绍我们近期发展的复标度和复动量表象方法及其对原子核单粒子共振态和奇特性质的研究。
        Speaker: Prof. Quan Liu (Anhui University)
        Slides
      • 8:50 AM
        原子核奇特转动结构的理论探索 20m
        在原子核结构领域,新的奇特转动模式被不断发现和研究。我们近期在理论方面探索了几种奇特转动模式。基于倾斜推转的协变密度泛函理论, 我们研究了Pd同位素中的候选的反磁转动带,通过微观地研究角动量的分布和方向, 首次展示了一种多空穴闭合形成的反磁转动模式。 通过协变密度泛函理论和粒子转子模型, 我们研究了$^{105}$Ag中近简并的三条转动带,首次讨论了在一个核中手征和赝自旋两种对称性破缺的共存,并讨论了如何在实验上区分两种对称性破缺所形成的双重带。 通过对偶偶核和奇$A$核中摇摆激发的系统计算, 我们讨论了摇摆带的电磁跃迁特征和角动量演化图像。 参考文献 [1] S. Frauendorf, and J. Meng, Nucl. Phys. A 617, 131 (1997) [2] H. Z. Liang, J. Meng and S. G. Zhou, Phys. Rep. 570, 1 (2015) [3] H. Jia, B. Qi*, C. Liu, Q. Hu, and S. Y. Wang*, Phys. Rev. C 97, 024335 (2018) [4] B. Qi*, H. Jia, C. Liu , and S. Y. Wang, Phys. Rev. C 98, 014305 (2018) [5] H. Jia, B. Qi*, C. Liu and S. Y. Wang, J. Phys. G, 46, 035102 (2019)
        Speaker: Dr Bin QI (Shandong University (Weihai))
        Slides
      • 9:10 AM
        奇奇核138Pm的高自旋态研究 20m
        潘昊楠1,马克岩1,陆景彬1,王豪1,张哲1,杨东1,马英君1,吕翌丰1,管弦1,杨清宇1,吴晓光2,贺创业2,郑 云2,李聪博2,李广生2, (1吉林大学物理学院,长春,130012 2中国原子能科学研究院,北京,102413) 摘要:实验上通过重离子融合蒸发反应124Te(19F,5n)138Pm,束流能量为105MeV,布居了目标核138Pm的高自旋态。对比早期的研究工作,21个新能级和47条新的γ跃迁被观测。在此基础上,一个新的与晕带具有相同πh11/2⊗νh11/2组态的正宇称伴带被建立。通过与晕带顺排角动量,B(M1)/B(E2)等实验值的比较,该伴带与晕带被建议为一对手征双重带,如图1所示。此外,138Pm核中另一个重要的物理问题是晕带自旋指定的不确定性。本工作通过顺排相加性以及该核区πh11/2⊗νh11/2组态带旋称反转的系统学研究,对138Pm核晕带最低观测态的自旋做了重新指定,发现新的自旋指定I0=9更接近相邻奇质子、奇中子原子核所对应的顺排量相加。同时,基于新的自旋指定,138Pm核晕带在低自旋出现了旋称反转,这与该核区普遍观测到的系统行为相一致。 ![enter image description here][1] [1]: http://b281.photo.store.qq.com/psb?/V12ErpVe1qnU1d/dns4TTU7fpycwzDCin6MfsArHJb5e3llhAFmwesgdIo!/c/dBkBAAAAAAAA&bo=QAMhA0ADIQMRECc!&rf=mood_app 图1:138Pm核的部分能级纲图 基金项目:国家自然科学基金(11775098、U1867210、11475072、11205069、11405072、); 吉林省科技发展计划项目(20190201137JC、20180520195JH);吉林省“十三五”科学研究规划项目JJKH20180117KJ;中央高校基本科研业务费专项资金项目。
        Speaker: 昊楠 潘 (吉林大学物理学院)
      • 9:30 AM
        奇奇核Br-74中可能存在的手征及摇摆现象的实验研究 20m
        我们在南非iThemba实验室利用Ni-58(F-19,2pn)Br-74反应道进行了研究Br-74高自旋态的在束γ谱学实验。实验获得了约3*10^9个二重符合事件以及4*10^8个三重及以上符合事件。本次实验观测到了Br-74共存在13条转动带。我们利用实验提取的ADO和线极化值确定了大部分能级的自旋和宇称。并且提取了正宇称部分能级寿命和跃迁的混合比。根据目前实验结果,我们认为正宇称的五条带中可能存在手征、摇摆效应以及形状共存,这可能是实验上发现的第一例手征及摇摆效应共存的原子核。目前数据处理正在进行中,上述结论还需进一步验证。
        Speaker: 睿巨 郭 (å)
        Slides
      • 9:50 AM
        实验研究奇奇核$^{74}$As的对称性自发破缺 20m
        基于南非iThemba国家实验室的AFORDITE探测阵列,通过重离子熔合蒸发反应$^{74}$Ge(α, 1p3n)研究了$^{74}$As的高自旋态能级结构。本工作拓展了已知的能级纲图\[1\],增加了34条新跃迁和13条能级,在正负宇称各建立了一对近简并的转动带,图1是本工作搭建的能级纲图。通过分析两对近简并带的能谱、S(I)和B(M1)/B(E2)(见图1),把正宇称的两条带指定为手征双重带,把负宇称的两条带指定为赝自旋伙伴带。 ![enter image description here][1] 图1. 本工作搭建的$^{74}$As的能级纲图,图中标红色的是新发现的能级和跃迁。 ![enter image description here][2] 图2. 两对近简并转动带的能谱、S(I)和E(I)的实验值。 [1]: https://s2.ax1x.com/2019/08/20/mYM9AJ.png [2]: https://s2.ax1x.com/2019/08/20/mYM3gP.png 参考文献: \[1\] S. P. Hu et al., Physics Letters B 732, 59 (2014).
        Speaker: Mr Xiao Xiao (Shandong University)
        Slides
    • 8:30 AM 10:10 AM
      S2: 核反应、核天体物理 科学会堂101

      科学会堂101

      华中师范大学

      武汉
      Conveners: Zhongzhou Ren (Tongji University) , 昌 许 (南京大学)
      • 8:30 AM
        光核反应的新应用:缪原子中的核极化效应 20m
        质子电荷半径通常可从氢原子光谱或电子-质子散射实验中测得。近来,瑞士PSI实验室通过测量缪氢($\mu$H)原子光谱中的兰姆位移,为质子半径的测量提供了一个更加精确的新实验方法。然而,这一新实验结果与已知质子半径相差5个标准差。由质子半径之谜所启发,一系列兰姆位移实验计划从不同的缪原子中提取出轻质量原子核($^2$H,$^3$H,$^3$He,$^4$He)的电荷半径。目前该实验的精度受限于一项理论输入量,即核极化效应对原子光谱的修正。 核极化效应是光核反应研究在原子物理中的应用,它与核光吸收截面的求和规则直接相关。通过结合核子间相互作用势与超球简谐展开多体方法的第一性原理计算,我们研究了缪原子中的核极化效应。这一理论研究为从缪原子光谱中精确提取原子核半径提供了重要理论输入。我们最近通过有效场理论与光学原理的结合,将核极化效应与虚光子康普顿散射相联系,从而为理论计算提供了新的方式。
        Speaker: Prof. 晨 计 (华中师范大学)
        Slides
      • 8:50 AM
        利用25Al(p,p)25Al共振散射研究关键天体反应22Mg(α,p)25Al 20m
        22Mg(α,p)25Al反应是αp过程中的关键核反应之一,其反应率的大小将直接对X射线暴的光曲线产生影响。由于22Mg(α,p)25Al反应的实验数据严重缺失,反应率仍依赖于统计模型的计算,存在非常大的不确定性。实验在东京大学原子核研究中心位于RIKEN的次级束装置CRIB上完成。实验中利用CRIB终端提供的能量为142 MeV的放射性次级束25Al轰击150μm的(CH2)n靶,利用靶后三套硅望远镜阵列对反冲粒子进行鉴别和测量,进而获得25Al(p, p) 25Al 的激发函数。实验观察到了复合核26Si的13条共振能级,其中5条高能共振能级目前仍无自旋宇称信息,2条共振能级的自旋宇称尚存在争议。利用R-Matrix理论工具拟合出了这些能级的自旋宇称以及质子宽度等信息。这些位于Gamow窗口内的能级将对反应率产生很大的影响。
        Speaker: Dr Jun HU (Institute of Modern Physics, Chinese Academy of Sciences)
        Slides
      • 9:10 AM
        7Li (p,γ) 8Be共振核反应厚靶产额及角分布新的测量方法 20m
        高能γ射线可用于许多领域,如核废料嬗变和核天体物理学。质子能量在441keV时将发生7Li(p,γ)8Be共振核反应,使用400μg/cm^2的LiF蒸镀到钽片上的厚靶,基于中国原子能研究所的加速器,我们将使用高纯锗探测器测量该反应释放14.8MeV和17.6MeV γ射线的产额及角分布。质子能量在992keV时27Al(p,γ)28Si发生共振核反应放出的高能γ射线对高纯锗探测器进行相对效率的刻度,56Co和152Eu的放射源对高纯锗探测器在低能部分进行绝对效率的刻度。
        Speaker: Mr 继红 魏 (北京师范大学,中国原子能科学研究院)
        Slides
      • 9:30 AM
        In-beam Measurement of 74Ge(p,γ)75As Reaction to Probe the Production Mechanism of Light p-process Nuclei 20m
        - Introduction The origin of heavy elements in the universe is an important frontier in the field of nuclear astrophysics. The p-process is mainly responsible for synthesizing the heavy elements on the proton-rich side[1]. 74Se is the lightest nucleus in the p-process, but its abundance predicted by the stellar model is three times higher than astronomical observations due to the lack of cross section data or their precision. 74Ge(p, γ)75As is the most critical nuclear reaction affecting 74Se abundance. For a typical stellar environment, the Gamow window of the 74Ge(p, γ)75As reaction is 1.2-3.8MeV, while so far, the previous experiments have been performed down to 1.6MeV[2,3]. We measured the cross section for Ep=1.4-2.8MeV using the 2×1.7 MV high-current tandem accelerator of the China Institute of Atomic Energy (CIAE). - Method Four high-purity germanium (HPGe) detectors were used to measure the prompt γ decays and its angular distribution cursed by proton capture reactions. Three detectors have a relative detection efficiency of 35%, and the fourth detector has a relative efficiency of 40%. The detectors were set as close as possible around the target. As shown in Figure 3, the distance was 8-9cm and the angle was 12°, 58°, 107.5° and 150° to the beam axis. The detector efficiency was calibrated with 152Eu source and 27Al(p, γ) reaction for Ep=992keV and Ep=760keV[4]. The target was made by evaporating 99.8% enriched 74Ge onto a thick tantalum backing using the evaporator at the CIAE. A target thickness of 283.3(15.0)μg/cm2 was verified through Rutherford Backscattering Spectrometry (RBS) performed at the tandem accelerator of Beijing Normal University. The 74Ge target was set at the end of a target pipe and was air-cooled during the experiment[5]. The proton energy was 1.4MeV-2.8MeV while the average energy loss in 74Ge target was 26.6keV-17.8keV, respectively. The beam intensity was set around 5μA, and was measured by a beam integrator. The target pipe was insulted from the rest of the accelerator, and it is 40cm long so that the loss of the secondary electrons was negligible. - Result In this experiment, 35 transitions to the g.s. were observed. For branching ratio differs from each proton energy, all transitions to the g.s. were used in the calculation of the total cross section. The angular distribution of all transition to g.s. was analyzed and fit by a sum of Legendre polynomials. Then the total cross section was given by the sum of each transition to g.s.. More then 980 peaks were analyzed in the spectrum for seven energise. Because of the large distance between detector and target and the low count rate, summing effects of the γ rays are negligible. - Conclusion The total cross sections of the 74Ge(p, γ)75As reaction were measured between 1.4 and 2.8 MeV using the in-beam γ spectroscopy measurement with HPGe detectors. The result matched with S.J. Quinn et al. and A. Suaerwein et al. very well, and provide cross sections data down to Ep=1.4MeV. The result would contribute to the stellar model and provide a better abundance prediction of the lightest p nucleus 74Se. - Reference [1]B. Guo, et al., Phys. Rev. C, 89(1), 12801(R) (2014); [2]S.J. Qinn, et al., Phys. Rev. C, 88,011603(R)(2013); [3]A. Sauerwein, et al., Phys. Rev. C, 86,035802(2012); [5]Y.L. Dang, et al., Chin. Phys. B, 6,131-134(2019); [4]A. Anttila, et al., Nucl. Instrum. Methods, 147, 501-505(1977); [5]Y.L. Dang, et al., Chin. Phys. B, 6,131-134(2019).
        Speaker: Mr Di Wu (China Institute of Atomic Energy)
        Slides
      • 9:50 AM
        29S β缓发质子衰变实验研究 20m
        放射性核素物理是国际核物理的前沿领域之一,远离β稳定线核结构信息是人们关注的热点。本次实验基于中科院近物所HIRFL-RIBLL1装置产生的$^{29}$S次级束束流注入三个双面硅条探测器,配合γ探测器阵列,对其衰变性质进行了实验测量。丰质子核$^{29}$S具有较大的β衰变分离能,故其发生β衰变后能更好地布居在非束缚态能级上。实验测量了$^{29}$S β缓发衰变的质子和γ能谱,抽取了$^{29}$S的半衰期,通过p-γ符合重建了$^{29}$P的衰变纲图,丰富了$^{29}$S和$^{29}$P的谱学信息。发现了此前D. J. Vieira实验中没有观测到的6个质子峰,指认出能量为3429 keV和3570keV质子峰的衰变末态,确认了2条新能级。通过与理论结果的对比,进一步支持了壳模型sd相互作用的可靠性,验证了$^{29}$S镜像核衰变的对称性。
        Speaker: Mr Fupeng Zhong (China Institute of Atomic Energy)
        Slides
    • 8:30 AM 10:10 AM
      S3:中高能核物理 9号楼9409

      9号楼9409

      华中师范大学

      武汉
      Conveners: Defu Hou (CCNU) , Huan Zhong Huang (Fudan University)
      • 8:30 AM
        寻找QCD相图的临界点:挑战,进展和展望 25m
        相变临界点是描述相结构最重要的特征量。QCD相图是否存在从一级相变到连续相变的临界点,是高能核物理方向还没有得到解答的重大问题之一。包括中国在内的世界科学强国都在进行或者计划进行重离子对撞来解答这个问题。此前,研究者通常用QCD物质的静态特诊去预言临界信号,但是在重离子对撞的环境下,临界信号最终将是由动力学特性所决定。 在这个报告中,我将综述这一前沿方向的新进展,并展望未来用于探索中高重子密度区的大型科学装置,如中国的HIRFL(Heavy Ion Research Facility in Lanzhou),将出现的新的物理发现的机遇。
        Speaker: Yi Yin (IMP)
        Slides
      • 8:55 AM
        QCD Phase structure from Lattice QCD 20m
        We will firstly present a lattice QCD based determination of the chiral crossover transition temperature at zero and nonzero baryon density[1]. We obtained a precise result for $T_{pc}=156.5\pm1.5$ MeV at zero baryon density. For analogous thermal conditions at the chemical freeze-out of relativistic heavy-ion collisions, we found $\kappa^B_2$=0.012(4) and $\kappa^B_4$=0.000(4). We will then present a first determination of chiral phase transition temperature in QCD with two degenerate, massless quarks and a physical strange quark mass[2]. After thermodynamic, continuum and chiral extrapolations we find the chiral phase transition temperature $T_c^0=132^{+3}_{-6}$ MeV. [1] A. Bazavov, H-T. Ding, P. Hegde et al., "Chiral crossover in QCD at zero and non-zero chemical potentials," Phys.Lett. B795 (2019) 15. [2] H.-T. Ding, P. Hegde, O. Kaczmarek et al.,, "The chiral phase transition temperature in (2+1)-flavor QCD,'' Phys.Rev.Lett. 123 (2019) 062002.
        Speaker: Prof. Heng-Tong Ding (Central China Normal University)
        Slides
      • 9:15 AM
        基于拓展的多相输运模型研究QCD相图及相关物理 20m
        多相输运模型是描述相对论重离子碰撞动力学演化的典型工具。我们对该模型的理论框架进行了拓展,用3味Nambu-Jona-Lasinio(NJL)模型描述部分子演化,并引入了重子、反重子、pi介子、及K介子的平均场势。其中,从NJL模型及其polyakov-loop扩展出发可以得到有效的QCD相图及夸克物质状态方程。我们基于拓展的多相输运模型研究了RHIC束流能量扫描实验中正反粒子椭圆流的劈裂。实验上正反核子和正反K介子的椭圆流劈裂对NJL拉氏量中的矢量耦合强度给出了约束,pi-和pi+介子的椭圆流劈裂对NJL拉氏量中的同位旋矢量耦合强度给出了约束。这些约束可以让我们进一步获取QCD相图及夸克物质状态方程的信息。 主要参考文献: [1] J. Xu, L.W. Chen, C.M. Ko, and Z.W. Lin, Phys. Rev. C 85, 041901(R) (2012); [2] J. Xu, T. Song, C.M. Ko, and F. Li, Phys. Rev. Lett. 112, 012301 (2014); [3] H. Liu, J. Xu, L.W. Chen, and K.J. Sun, Phys. Rev. D 94, 065032 (2016); [4] H. Liu, F.T. Wang, K.J. Sun, J. Xu, and C.M. Ko, arXiv: 1908.01156 [nucl-th].
        Speaker: Dr Jun Xu (Shanghai Institute of Applied Physics, CAS)
        Slides
      • 9:35 AM
        Search for the QCD Critical Point in Relativistic Heavy-Ion Collisions at RHIC 20m
        Experimental confirmation of the QCD critical point is an excellent test of QCD theory in the non-perturbative region and a landmark of exploring the QCD phase structure. It is one of the main goals of the RHIC Beam Energy Scan (BES) program. Fluctuations of conserved quantities, such as baryon, electric charge and strangeness numbers are sensitive observables in relativistic heavy-ion collisions to probe the QCD phase transition and search for the QCD critical point. The STAR experiment has measured the fluctuations of net-proton (proxy for net-baryon (B)),net-kaon (proxy for net-strangeness (S)), and net-charge (Q). These measurements are important for understanding the phase structure of the quark matter at finite baryon chemical potential and temperature. In this seminar, I will present the cumulants of the net-proton, net-kaon and net-charge multiplicity distributions from thefirst phase of the Beam Energy Scan program at the Relativistic Heavy Ion Collider (RHIC). The corresponding physics implications and future plan will be discussed.
        Speaker: Dr Xiaofeng Luo (Central China Normal University)
        Slides
      • 9:55 AM
        Charmed baryon production with ALICE 15m
        Charm quarks are effective tools to study the properties of the Quark-Gluon Plasma (QGP) formed in heavy-ion collisions at the LHC. Due to their large mass, they are produced during the early stages of the collisions in hard-scattering processes, on a time interval shorter than the QGP formation time. Thus, they experience the whole evolution of the system. The measurement of charmed baryon production in heavy-ion collisions provides unique information on hadronisation mechanisms, constraining the role of coalescence and testing the predicted presence of diquark states in the medium. Measurements of charmed baryon production in small systems (pp and p--Pb collisions) provide the reference necessary for interpreting results in Pb--Pb collisions. In addition, in pp collisions, they allow to study the hadronisation of charm quarks, and allow testing QCD calculations. Measurements in p--Pb collisions are fundamental to disentangle cold nuclear matter effects from those deriving from the presence of the QGP. ALICE detector is well suited to detect charmed baryons down to low transverse momentum ($p_{\rm T}$), thanks to the excellent tracking capabilities and state-of-art particle identification. In this contribution, the latest ALICE results on charmed baryon production in Pb--Pb collisions will be shown. The measurement of the $\Lambda_{\rm c}$ production, nuclear modification factor and the $\Lambda_{\rm c}/ {\rm D}^{0}$ ratio in central and semi-central events in a large $p_{\rm T}$ interval will be discussed together with the comparison with the results in pp and p--Pb collisions and theoretical models. In addition, the measurement of the $\Xi_{\rm c}$ baryon in pp and p--Pb collisions will be presented.
        Speaker: 秀秀 蒋 (C)
        Slides
    • 8:30 AM 10:10 AM
      S4:探测器和电子学及应用技术 科学会堂301

      科学会堂301

      华中师范大学

      武汉
      Conveners: 正国 胡 (近物所) , 翔舟 蔡 (中国科学院上海应用物理研究所)
      • 8:30 AM
        先进核反应堆物理高保真数值模拟与不确定度量化 25m
        先进核能系统的研发需要以高保真数值模拟为基础,包括高保真核反应堆物理数值计算、热工水力计算、燃料性能分析计算以及多物理耦合分析与不确定度量化。本报告重点介绍西安交通大学核工程计算物理实验室近年来在核反应堆高保真数值模拟与软件开发方面的研究进展,主要包括基于全堆芯三维输运计算的高保真中子学计算、多尺度高保真热工水力分析计算、精细模型的核燃料堆内服役性能高保真计算、大规模问题的高性能计算实现技术等研究内容,以及在所开发的计算模型和软件平台基础上,开展高保真计算平台的验证、确认及不确定性定量研究。
        Speaker: Prof. 良志 曹 (西安交通大学)
        Slides
      • 8:55 AM
        中国极化电子离子对撞机EicC 20m
        Electron Ion Collider (EIC), regarded as the ”super electron microscope”, can provide the clearest image inside of the nucleon. It is the most ideal tool to understand the internal structure of the nuclear matter, especially the quark-gluon structure of the nucleon and nuclei. Polarized EICs are the next generation ”multi-dimensional electron microscopes” that are most effective in studying the deep structure and strong interactions of particles. Based on the Heavy Ion High Intensity Accelerator Facility which is under construction since the end of 2018 in Huizhou, the IMP is proposing to build a high luminosity polarized EIC facility in China, named ”EicC”, to carry out the frontier research on nucleon structure studies. In this talk, the current status of the EicC will be presented, including the considerations on detector design and the physics programs.
        Speaker: Prof. Yutie Liang (Institute of Modern Physics, CAS)
        Slides
      • 9:15 AM
        SHANS上MRTOF质谱仪的研制进展 20m
        多反射飞行时间质谱仪 (MRTOF-MS) 是在传统的飞行时间质谱仪的基础上发展起来的一种新型实验仪器,它可以将带电粒子约束在一定空间内使其往返运动,通过延长离子的飞行时间而获得较高的质量分辨本领。这种仪器不仅具有测量精度较高、测量过程较简单且不受杂质干扰、质谱测量范围广等特点,而且具有结构紧凑、机械构造相对简单和造价较低等优势。 近代物理研究所正在充气反冲核分离器 (SHANS) 后端建造 MRTOF-MS。它由参考离子源、束流传输器件、质量分析器核心部分、探测器、真空系统和控制与数据获取系统等部分组成。该谱仪具有两方面的功能:一是用于原子核质量的直接精确测量;二是用作质量选择器,高效、快速地提供单一的目标核,为激光核谱学和在线 $\beta$ 谱学等后续研究提供“干净”的测量环境。 当前,已完成 MRTOF-MS 的核心部分 MRTOF 质量分析器的研制。其研制过程包括模拟优化、机械设计、机械加工、机械装配和离线调试等。在模拟与优化部分,我们利用下山单纯形算法结合 SIMION 开发了一套专用软件,在“镜电极开关”和“调能腔”两种模式下计算了不同初始条件下的电压设置组合及最佳质量分辨本领 $R_{max}$,优化了最佳漂移管长度 $L$,定量地给出了电源精度的参考范围。结果显示:质量分辨本领 $R>100~000$, 建议漂移管的最佳长度 $L \approx 400$ mm,电源精度和稳定性要求好于 $50$ ppm。以模拟结果为参考,我们完成了机械设计与建造,并完成了初步离线调试,测量结果显示:其约束时间可达 $10$ ms,质量分辨本领 $R \approx 20~000$。
        Speaker: Dr 玉林 田 (中国科学院近代物理研究所)
        Slides
      • 9:35 AM
        基于探测LCS伽玛射线的三晶电子对谱仪的研制和测试 20m
        在激光康普顿背散射(LCS)产生的伽玛射线的测量中,往往会有电子束产生的韧致辐射的光子本底对测量的结果有干扰,因此在探索和测量LCS伽玛射线的过程中,选择合理和合适的探测器的尤为重要。高纯锗探测器在强本底的辐照中有可能会有所损坏,而单个的量能器则不能很好的将本底区别出来。因此,我们选择了三晶电子对晶体谱仪,三晶电子对谱仪是利用大于1.022MeV的光与物质相互作用发生的电子对效应的原理通过三个晶体探测器的三重符合来测量LCS产生的伽玛信号,我们的中心晶体用的是直径2x2inch的圆柱形BGO和LaBr晶体,两侧用的是直径5x3inch圆柱形碘化钠晶体。我们通过NIM插件搭建了能够符合测量伽玛射线的电子对晶体谱仪系统,并用Co56放射源以及(p,γ)反应伽玛源进行了测试和能量以及效率标定,也用genat4进行了简单的效率模拟,取得了一些有意义的结果。
        Speaker: Mr 伏龙 刘 (北京师范大学,中国原子能科学研究院)
        Slides
    • 10:10 AM 10:30 AM
      茶歇 20m
    • 10:30 AM 12:10 PM
      S1: 核结构 科学会堂201

      科学会堂201

      华中师范大学

      武汉
      Conveners: Dr Shouyu Wang (School of Space Science and Physics, Shandong University at Weihai) , 早春 高 (中国原子能科学研究院)
      • 10:30 AM
        Shell-model study from light to heavy nuclei and a preliminary uncertainty investigation 20m
        There are huge amount of nuclear data, including masses, levels, EM properties, alpha and beta decay half-lives. It is worth to know the uncertainties between these observed data and calculations within one model and one nuclear force. In this talk, I will introduce the nuclear shell model and its applications on light, medium, and heavy nuclei from Be to Np. Some preliminary results on the uncertainties of nuclear models will be presented. Systematic investigation on the uncertainty of shell model is helpful for nuclear astrophysics and reactor physics.
        Speaker: Dr Cenxi YUAN (Sun Yat-sen University)
        Slides
      • 10:50 AM
        奇A核119Sb中奇异运动模式的实验研究 20m
        通过重离子熔合蒸发反应$^{116}$Cd($^{7}$Li,4n)布局了$^{119}$Sb的高自旋态,本次工作更新了$^{119}$Sb的能级纲图,共增加了40条新的$\gamma$跃迁,20个新能级,其中包括一条新的转动带(带4)。$^{119}$Sb能级结构展现出单粒子激发与转动带结构共存,其中单粒子结构基本是由Z=50壳之外的价核子分别占据$\pi$$d_{5/2}$、$\pi$$g_{7/2}$、$\pi$$h_{11/2}$轨道与$^{118}$Sn核芯的能级耦合而形成的。我们基于协变密度泛函理论(CDFT)与粒子转子模型(PRM)研究其转动带结构(带1,2,3,4,5 ,6),建议带1是基于组态$\pi$ $g^{-1}_{9/2}$的电转动带,带2是$g^{-1}_{9/2}(d_{5/2}/g_{7/2})^{2}$$\otimes \nu h_{11/2}h_{11/2}$组态的磁转动带,带3和带4是基于组态$g^{-1}_{9/2}(d_{5/2}/g_{7/2})^{2}$$\otimes \nu h_{11/2}d^{-1}_{5/2}$的手征双重带,带5和带6是分别基于组态$g^{-2}_{9/2}(d_{5/2}/g_{7/2})^{3}$$\otimes \nu h^{2}_{11/2}$,$g^{-2}_{9/2}(d_{5/2}/g_{7/2})^{2}h^{1}_{11/2}$$\otimes \nu h^{2}_{11/2}$的反磁转动带。综上所述,我们的研究表明$^{119}$Sb的能级结构中存在着单粒子激发、电转动、磁转动、反磁转动、手征转动现象。这是首次在同一个原子核中观测到如此多种类的运动模式共存。
        Speaker: Dr hui jia (山东大学(威海),空间科学与物理学院)
        Slides
      • 11:10 AM
        原子核壳模型的研究与应用 20m
        在原子核微观模型研究中,壳模型是原子核结构理论中应用最广泛的微观模型之一。对于质量数较小或满壳外价核子数较少的原子核,壳模型可以很好地解释原子核低激发现象。 在壳模型中,剩余两体相互作用是重要的输入量,以往的壳模型主要采用有效两体相互作用和唯象相互作用(即对力加多极相互作用)两种形式。有效两体相互作用的形式比较复杂,其优点是计算结果与实验值很接近。缺点是物理意义不明显且在重核区很难拟合相互作用参数;唯象相互作用适合研究原子核低激发态,其优点是相互作用形式简单,参数少,有直接的物理意义。缺点是参数具有不确定性,例如“一核一调”、不同研究组给出的参数有明显区别等,从而对实验现象的分析和未知原子核性质的预言造成困难。 在本工作中,我们初步研究sd 壳和 pf 壳的唯象相互作用及其应用,主要考察同位旋矢量的单极对力和四极对力,同位旋标量自旋为一的对力和自旋平行的对力,以及四极—四极相互作用。然后分别针对 sd 壳和 pf 壳的偶偶核低激发态能级进行相互作用参数拟合,为了更好的描述原子核结合能和单粒子演化的过程,我们在计算中利用 usdb 和 gxpf1 相互作用提取单极相互作用,并扣除唯象相互作用中的单极成分。计算结果表明对于偶偶核低激发态,唯象加单极相互作用计算值与实验值的误差较小,其精度与有效两体相互作用的精度很接近。唯象加单极相互作用可以解释原子核对称能、Wigner 效应、质子—中子相互作用奇偶性等现象。下一步我们计划用算符归一化方法研究适用于多个核区的唯象相互作用普适标度(universal scaling)参数,结合壳模型配对近似理论描述或预言重核区原子核低激发态性质。 参考文献: 1. Marianne Dufour and Andres P, Zuker. Realistic collective nuclear Hamiltonian, Phys. Rev. C (1996), 1641-1660 2. M. Hasegawa, K. Kaneko, S. Tazaki, Nucl. Phys. A 674 (2000), 411-445 3. Kazunari Kaneko, Munetake Hasegawa, and Takahiro Mizusaki, Quadrupole and octupole softness in the N=Z nucleus 64Ge, Phys. Rev. C 66 (2002), 051306(R) 4. M. Hasegawa, K. Kaneko, S. Tazaki, Improvement of the extended P+QQ interaction by modifying the monopole field, Nucl. Phys. A 688 (2001), 765-788 5. M. Hasegawa, K. Kaneko, S. Tazaki, Improvement of the extended P+QQ interaction by modifying the monopole field, Nucl. Phys. A 688 (2001), 765-788 6. M. Hasegawa, K. Kaneko, S. Tazaki, Improvement of the extended P+QQ interaction by modifying the monopole field, Nucl. Phys. A 688 (2001), 765-788 7. M. Hasegawa, K. Kaneko, and T. Mizusaki, Particle alignments and shape change in 66Ge and 68Ge, Phys. Rev. C 71 (2005), 044301 8. Kazunari Kaneko, Yang Sun, Takahiro Mizusaki, and Munetake Hasegawa, Shell-model study for neutron-rich sd-shell nuclei, Phys. Rev. C 83 (2011), 014320 9. K.Kaneko, T.Mizusaki, Y.Sun, S.Tazaki, Systematical shell-model calculation in the pairing-plus-multipole Hamiltonian with a monopole interaction for the pf5/2g9/2 shell, Phys. Rev. C (2015), 04431 10. G. J. Fu, Hui Jiang, Y. M. Zhao, and A. Arima, Residual proton-neutron interactions and the NpNn scheme, Phys. Rev. C 82 (2010), 014307
        Speaker: Mr 冶秋 贺 (å)
        Slides
      • 11:30 AM
        用AMD对不同核子-核子间相互作用势对原子核基态结合能的研究 20m
        与高能重离子核反应不同,低能重离子核反应中弹靶的效应起着非常重要的作用,这就要求我们所用的输运模型对基态核的性质有更合理的描述。我们常用的反对称化的分子动力学(AMD)模型可选的核子-核子间相互作用势有三种Gogny、Volkov、Skyrme,本文通过AMD-V中Gogny的不同核子-核子间相互作用势gas、d1g3和g0,计算原子序数从1到18不同核同位素的结合能并与实验值进行比较,以及 $^{14}C$和d反应的能谱分布,发现对于不同的NN相互作用势所得能谱分布有较大区别,并且对不同核的同位素会有某一NN相互作用势重现的结合能与实验值符合的更好。
        Speaker: Mr 金成 王 (内蒙古民族大学)
        Slides
      • 11:50 AM
        基于我国大科学装置的在束谱学研究及其技术发展展望 20m
        大科学装置上的在束谱学研究是当前核物理研究的重要领域,特别是随着我国核科学的发展,未来在我国已建成和将要建设的大科学装置上开展不稳定核在束伽马谱学测量及其它相关研究是很重要的前沿物理研究工作。同时其发展起来的在束伽马谱学测量技术也是重要的探测技术,不同于以往传统的离线伽马谱学测量,在束伽马谱学测量是在大科学装置的加速器上利用多探头多角度的伽马探测器单元组成的高分辨伽马探测阵列开展在束伽马谱学测量,并开展相关核科学方面的前沿课题研究,是目前世界各大核物理实验室的重要研究手段,该项技术在相关核结构、核反应、核天体、核数据、先进核能、核技术应用等方面能得到很好的应用。本报告将介绍我国大科学装置上的在束谱学研究现状及取得的成果,并重点介绍下一步的发展计划,先进实验装置建设,以及在前沿核物理研究和核数据测量等领域的应用和展望。
        Speaker: 晓光 吴 (中国原子能科学研究院)
        Slides
    • 10:30 AM 12:10 PM
      S2: 核反应、核天体物理 科学会堂101

      科学会堂101

      华中师范大学

      武汉
      Conveners: Prof. Chunlin Bai (School of physics, Sichuan University) , 承键 林 (中国原子能科学研究院)
      • 10:30 AM
        中能区截面介质修正的同位旋效应系统学研究 20m
        基于一个自洽的相对论的BUU方法,考虑同位旋不对称核物质中核子和$\Delta$重子的有效质量劈裂,分别研究了$\Delta$共振态的硬过程($NN\rightarrow\Delta$)和软过程($ N\pi\rightarrow\Delta$)产生截面及$\Delta$ 的衰变宽度在同位旋不对称核体系下的介质修正(包括能量、密度、特别是同位旋依赖的) 效应。结果表明,类似于核子-核子弹性散射过程,$\Delta$硬过程产生截面的密度修正及在同位旋不对称体系下的质量劈裂效应都比较强烈,而$\Delta$的软过程产生截面及衰变宽度的密度依赖和质量劈裂效应都相对较弱。通过考虑对pion介子质量的介质修正,$\Delta$的软过程产生截面随着密度的增加而适当的降低。同时,如果系统的不变质量与$\Delta$ pole 质量相差不大,则$\Delta$ 的衰变宽度对密度的依赖较弱。相比于pion介子,不同带电核子和$\Delta$ 重子的有效质量劈裂对$\Delta$的软过程产生截面的影响更明显。对硬过程,其截面最大的劈裂效应出现在$\Delta^{++}$和$\Delta^-$的产生道中,而对软过程,在$\pi^{-}p\rightarrow\Delta^{0}$和$\pi^{+}n\rightarrow\Delta^{+}$的反应道中可以看到最大的质量劈裂效应。
        Speaker: Prof. Qingfeng Li (School of Science, Huzhou University)
        Slides
      • 10:50 AM
        基于TMSR白光中子源的截面数据测量 20m
        依托中国科学院“未来先进核裂变能战略性先导科技专项--钍基熔盐堆核能系统(TMSR)”,建设了国内首台专用于核数据测量的紧凑型白光中子源。装置主要由:脉冲型15 MeV电子加速器及其辅助系统;中子产生靶系统;探测系统及控制获取系统三个部分组成。装置电子打靶脉冲频率1-266 Hz,脉冲宽度3 ns—3μs,电子打靶最高平均功率1500 W,最高中子产额~1*E+11 n/s,中子飞行时间谱仪飞行距离5.8 m。基于该装置已开展钍的总截面测量,在能量0.005~1 eV区间测量误差小于3.0 %,与美国ENDF/B-Ⅶ.1评价数据基本一致,验证了该装置的可靠性。同时,开展了TMSR慢化材料石墨的总截面和硼中子当量测量,建立了快速检测石墨硼中子当量的方案,给出了石墨宏观吸收截面和硼中子当量的刻度曲线。搭建了样品加热装置,国内首次开展了高温哈氏合金和熔盐的热中子散射截面测量,初步解决了高温熔盐热中子散射截面理论数据的分歧,为TMSR实验堆物理设计提供了可靠的核数据。
        Speaker: Dr jingen chen (Shanghai Institute of Applied Physics, Chinese Academy of Sciences)
        Slides
      • 11:10 AM
        锗同位链中子俘获截面的高精度测量研究 20m
        74,76Ge(n,γ)反应是大质量恒星氦核心和碳燃烧壳层弱s-过程中的关键反应,决定了宇宙中锗同位素的丰度。同时又是76Ge无中微子双贝塔衰变0νββ实验,中子诱导的主要本底反应。当前已有的实验数据受实验条件或中子能区的限制,存在精度不高且部分能区缺失的情况。 本工作将:1)基于绵阳中子科学平台(PD-300中子发生器)、北京大学4.5MV静电加速器中子源,应用活化法开展74,76Ge中子俘获反应截面的高精度测量研究。2)基于中国散裂中子源的反角通道白光中子源实验终端,中子束流所具有非常宽的能谱和很好的时间特性。应用瞬发伽马射线法开展74,76Ge中子俘获反应的高精度测量研究。 结合两种方法,将有望给出20keV-15MeV能区不确定度低于5%的74,76Ge(n,γ)反应截面值。特别是核天体物理最关注的30keV附近能区截面的直接测量工作,将为理解大质量恒星s-/r-过程提供关键的核物理输入量,帮助解决“从铁到铀的元素是如何产生的?”这一重大物理问题。同时,为国际上正在开展的GERDA组和MAJORANA组76Ge0 νββ实验、以及未来锦屏深地实验室清华大学CDEX组吨量级的高纯锗探测器0νββ实验研究,提供高精确本底反应数据。 关键字:s-过程;无中微子双贝塔衰变;74,76Ge(n,γ)反应;活化法;瞬发伽马射线法
        Speaker: 振东 安 (sysu)
        Slides
      • 11:30 AM
        基于极化氦三靶的重离子碰撞实验 20m
        利用极化的氦三气体靶可以显著地拓展传统的核物理实验研究,观察初态自旋自由度对核反应过程动力学的影响。本文通过列举极化三体核力实验以及极化的重离子电荷交换反应实验,介绍了极化氦三靶在核物理实验研究中的独特优势。相对于(p,n)反应,氦三核参与的电荷交换反应对于重离子外壳层的中子更敏感,通过这一反应测量丰中子核的中子半径与质子半径之差,对于理解丰中子核结构、中子星的性质等问题提供了新的实验观测手段。而在极化的电荷交换反应中,通过控制靶极化方向可以分离π介子交换与ρ介子交换对于核子自旋同位旋激发的贡献,进一步为研究核子在不同核环境中的动力学演化提供独一无二的契机。
        Speaker: Yi Zhang (L)
        Slides
      • 11:50 AM
        25Mev/u 86Kr + 208Pb 裂变与符合轻粒子发射的实验研究 20m
        报告人:清华大学 博士生刁昕玥 在中低能的核反应所发生的裂变事件中,由于裂变产生的颈部具有低密、高中子丰度、时标较长等特征,颈部发射的粒子具有显然的丰中子特性,对这些发射粒子的同位旋成分及其随时间演化进行分析,可以约束低密度区的核对称能随密度的依赖行为。 基于此研究意义和物理目标,我们于2019年6月底至7月初在兰州近物所RIBLL1终端完成25Mev/u 86Kr + 208Pb实验,来探究重离子核反应中裂变体系形变大小及其对核物质性质的依赖性研究。希望通过本次报告向大家介绍我们本次实验初步的物理目标、所用的HIRATU探测器阵列、实验进展情况等。 实验中我们采用PPAC+硅条望远镜阵列测量碎片和轻粒子。采用3个240*280 mm^2 有效面积的PPAC(Parallel Plate Avalanche Counter平行板雪崩探测器)测量裂变碎片,该探测器可以很好地测量到裂变碎片的到达时刻和位置,时间分辨随着电压的增加而增加,优于300ps;随着电压的增加,对α粒子的探测效率接近100%;探测器可以在-650V高压、7.5mbar的环境下稳定工作(超过120h)。同时,我们采用4个64 * 64〖 mm〗^2的半导体望远镜(单面硅条+双面硅条+CsI)测量关联轻粒子,硅条位置分辨2mm,角度分辨优于1°,可以很好的区分轻粒子的种类及能量。
        Speaker: 昕玥 刁 (Tsinghua University)
        Slides
    • 10:30 AM 12:10 PM
      S3:中高能核物理 9号楼9409

      9号楼9409

      华中师范大学

      武汉
      Conveners: Prof. Qinghua Xu (Shandong University) , Prof. Yifei Zhang (University of Science and Technology of China)
      • 10:30 AM
        Open and Hidden Heavy Flavor Production with RHIC-STAR 20m
        Heavy quark provides an excellent prob of the hot dense medium created in ultra-relativistic heavy-ion collisions due to its larger masses. The heavy flavor quark are dominantly produced before the quark-gluon plasma (QGP) formation and then transport in the medium and hadronization when the medium is cooling down. Measurements of open heavy flavor hadron production in ultra-relativistic heavy-ion collisions can be used study the QGP properties. While the production of hidden heavy flavor (quarkonium) is expected to be suppressed in ultra-relativistic heavy-ion collisions due to the color-screening of the potential of heavy quark and its anti-quark and has been proposed as smoking-gun signal of QGP formation. Recent years, thanks to the newly installed Heavy Flavor tracker (HFT) and Muon Telescope Detector (MTD) detectors, RHIC-STAR experiment has achieved a serious high quality data on the open and hidden heavy flavor production in ultra-relativistic heavy-ion collisions. In this talk, I will review these experimental results. Physics implications will also be discussed.
        Speaker: Prof. Zebo Tang (University of Science and Technology of China)
        Slides
      • 10:50 AM
        D-meson production in pp and heavy-ion collisions measured with ALICE at the LHC 20m
        Heavy quarks (charm and beauty) are a powerful probe of the Quark-Gluon Plasma (QGP) formed in high-energy heavy-ion collisions. They are produced in hard scattering processes on a timescale shorter than the QGP formation time and experience the whole system evolution. The measurement of the nuclear modification factor (RAA) of open heavy flavours can provide important information about the microscopic interactions of heavy quarks with the medium constituents, in particular on the colour-charge and parton-mass dependence of heavy-quark energy loss. The measurements of the elliptic flow (v2) at low pT can give insight into the participation of the heavy quarks to the collective expansion of the system and their thermalization in the medium. These two observables can also help in understanding possible modifications of heavy-quark hadronisation in the medium. In particular, the role of the recombination mechanism can be studied for charm via the comparison of D mesons without strange-quark content with D+s and charm baryons. The measurements in pp collisions provide critical tests of models of charm hadronisation in vacuum. In this talk, the latest results on pT-differential RAA and v2 of D mesons measured at mid-rapidity in Pb-Pb collisions with ALICE will be presented. The pT-differential cross section of the non-prompt D0 in pp collisions will be presented.
        Speaker: Dr XINYE PENG (CCNU)
        Slides
      • 11:10 AM
        Charm and beauty isolation in heavy flavor electron measurements at RHIC 20m
        Heavy quarks (charm and beauty) are believed to be produced predominantly in hard scattering processes at early stage of the collisions before the QGP production so they can pass through the hot-dense medium completely, and their production yields can be calculated by perturbative-QCD, which makes them ideal probes for QGP. According to the theoretical prediction, energy loss of heavy quarks is less than that of light quarks due to the suppression of the gluon radiation angle by the quark mass. Heavy quarks could be more difficult to be thermalized than light quarks in the hot-dense medium and moved following the collective flow during the expansion of the partonic matter. Because of its three times larger mass compared with that of charm, beauty could have different properties in terms of its interactions with QGP medium from charm. We develop a data-driven method to isolate charm and beauty contributions from the inclusive heavy flavor electrons based on the most recent open charm hadron measurements in minimum bias Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200 GeV at RHIC. The individual electron nuclear modification factor ($R_{\rm AA}$) and elliptic flow ($v_2$) from charm and beauty decays will be reported. Model comparisons and discussions will also be given.
        Speaker: Mr Fan Si (University of Science and Technology of China)
        Slides
      • 11:30 AM
        Measurement of J/$\psi$ production at mid-rapidity in proton-proton collisions at $\sqrt{s}$ = 510 and 500 GeV with the STAR detector 20m
        The production of heavy quarkonia has been extensively used to probe the Quark-Gluon Plasma (QGP) created in heavy ion collisions. The suppression of 𝐽/$\psi$ in a deconfined medium due to Debye color screening of the charm quark potential has been proposed as a signature of the QGP formation. Interpretation of 𝐽/$\psi$ suppression requires good understandings of its production mechanism in elementary collisions. Despite decades of efforts, the 𝐽/$\psi$ production mechanism in p+p collisions is still not fully understood. 𝐽/$\psi$ measurements in p+p collisions can provide additional insights into its production mechanism. We present the measurements of the production cross-sections of the J/$\psi$ meson as a function of transverse momentum, as well as its yield dependence on charged-particle multiplicity in proton-proton collisions at center-of-mass energies of 510 and 500 GeV using data recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC).
        Speaker: Qian Yang (Shandong University)
        Slides
      • 11:50 AM
        Upsilon measurements in Au+Au collisions √sNN = 200 GeV with the STAR experiment 20m
        Measurements of quarkonium production play an important role in understanding the properties of the Quark-Gluon Plasma (QGP) created in relativistic heavy-ion collisions. Quarkonium suppression in the medium due to the color screening effect has been proposed as a direct signature of the QGP formation. However, other effects, such as cold nuclear matter (CNM) effects and regeneration, add additional complications to the interpretation of the observed suppression. Compared to charmonia, bottomonia not only gain less contribution from regeneration due to the smaller b-quark production cross-section but are also less affected by the CNM effects. Furthermore, different bottomonium states with different binding energies are expected to dissociate at different temperatures, thus the measurement of this “sequential melting” can help constrain the thermodynamic properties the medium. In this talk, we will present the latest measurements of $\Upsilon$ production in Au+Au collisions at √sNN = 200 GeV via both di-muon and di-electron channels by the STAR experiment. With a combination of the data sets taken in 2011, 2014 and 2016, the precision of $\Upsilon$ measurements will be significantly improved compared to previous preliminary results, especially for the excited $\Upsilon$ states. The nuclear modification factors for ground and excited $\Upsilon$ states will be shown as a function of transverse momentum and centrality, and compared to those measured at the LHC as well as to theoretical calculations.
        Speaker: Pengfei Pengfei Wang (USTC)
        Slides
    • 10:30 AM 12:10 PM
      S4:探测器和电子学及应用技术 科学会堂301

      科学会堂301

      华中师范大学

      武汉
      Conveners: 太平 彭 (中国工程物理院核物理与化学所) , 志芳 吴 (tsinghua)
      • 10:30 AM
        Forward Silicon Tracker Upgrade for the STAR Detector 20m
        The STAR Collaboration plans to design, construct, and install a suite of new detectors in the forward rapidity region (2.5 < eta < 4) over the next two years, enabling a program of novel measurements in pp, pA, and AA collisions. This extension of STAR’s kinematic reach will allow detailed studies of cold QCD physics at both very high and very low partonic momentum fraction, and will enable studies of the longitudinal structure of the nuclear initial state and fragmentation regions in heavy-ion collisions. Forward silicon tracker (FST) is the sub-system closest to the collision interaction points and provide tracking along with small-strip Thin Gap Chambers (sTGC) in STAR proposed forward upgrade program. FST consists of three layers of silicon disks based on single-sided double-metal Silicon microstrip detector technology. The readout of silicon sensors will be transmitted to the DAQ system through APV25 chips, which will be wire-bonded to the flexible circuit board. We will discuss the FST design and prototype plan and status in this talk.
        Speaker: 家宁 董 (山东大学)
        Slides
      • 10:50 AM
        ALICE ITS upgrade 20m
        A Large Ion Collider Experiment(ALICE) at the Large Hadron Col- lider (LHC) at CERN will undergo a major upgrade during the 2nd LHC Long Shutdown (LS2) scheduled in 2019-20 that will allow to study in de- tail Quark-Gluon Plasma (QGP) properties exploiting the increased Pb-Pb luminosity expected during Run 3 and Run 4. The replacement of the ex- isting Inner Tracking System (ITS) with a completely new ultra-light high- resolution detector is one of the cornerstones within this upgrade program. The new ITS will consist of seven layers of an innovative Monolithic Active Pixel Sensors (MAPS) with the innermost layers sitting at only 22 mm from the interaction point. It’s made of seven concentric detector layers based on a 50 μm thick MAPS chip (called ALPIDE) with a pixel pitch of 27×29 μm. The upgraded ITS will be realized using more than twenty-four thousand ALPIDE chips covering a total active surface of about ten square meters. The main features of the new ITS are of low material budget, high granu- larity and low power consumption. This talk will focus on the design and the physics performance of the new ITS, as well as the advanced techniques adopted in detector assembly and integration will be introduced. The status and commissioning of the ITS upgrade project will be reported.
        Speaker: Mr Biao ZHANG (CCNU)
        Slides
      • 11:10 AM
        Forward sTGC Tracker Upgrade for the RHIC-STAR Detector 20m
        RHIC-STAR experiment is planning to upgrade the Forward Tracking System (FTS) which is consist of Forward Silicon Tracker (FST) and Forward sTGC Tracker (FTT). The small-strip Thin Gap Chambers (sTGC) are designed to provide precision position measurement at about 100um level for the charged particles in high luminosity, covering forward rapidity region (2.5 < eta < 4). The extended rapidity coverage on particle identification enables lots of physics opportunities in pp, pA and AA programs beyond 2020 at STAR. Two size of sTGC prototypes have been designed and produced at Shandong University. In this talk, we will present the sTGC prototype R&D details for the STAR forward upgrade. Some performance test results will be discussed together with the upgrade status and plan.
        Speaker: Mrs Shi Yingying (Shandong University)
        Slides
      • 11:30 AM
        高时间空间分辨伴随α探测器的研制 20m
        关联粒子成像技术(API)是进行爆炸物检测和有源核查的重要手段,而关联α粒子探测器的空间分辨和时间分辨直接决定成像系统的空间分辨能力。依托核数据重点实验室移动中子发生器,利用具有快时间响应的ZnO:Ga与最新的位置灵敏光电倍增管(PSPMT)H13700结合,设计了可用于API的关联α粒子探测器系统。通过SCDC-TOCG将256路信号简化为4路信号,利用数字化仪对信号进行采集分析。通过离线实验和在线实验对关联粒子探测器的时间性能和空间分辨性能进行了测试。利用刀口法测得空间分辨好于1mm,并通过狭缝法和栅条法进行了验证。通过测量Cf252裂变碎片和瞬发伽马符合测量获得系统时间分辨好于1ns,在小型移动中子发生器上测得的n-α关联时间分辨小于0.8ns。
        Speaker: Mr Kai Zhang (CIAE)
    • 12:10 PM 1:30 PM
      午餐 1h 20m 桂苑宾馆

      桂苑宾馆

      华中师范大学

      武汉
    • 1:30 PM 3:30 PM
      S1: 核结构 科学会堂201

      科学会堂201

      华中师范大学

      武汉
      Conveners: Dr Cenxi YUAN (Sun Yat-sen University) , 峰 潘 (辽宁师范大学)
      • 1:30 PM
        Ab initio Gamow in-medium similarity renormalization group with resonance and continuum 20m
        Resonance is a general phenomenon which can happen in classic or quantum systems. An unbound many-body quantum system can undergo a self-resonant process. It has long been a challenge how to describe unbound many-body open quantum systems in resonances. We have developed an ab initio Gamow in-medium similarity renormalization group (IM-SRG) method capable of describing resonance and non-resonance continuum properties of weakly-bound or unbound nuclear systems. To include the continuum effect, the Gamow-Berggren representation has been employed into the IM-SRG framework for the first time. We extend IM-SRG to the complex-energy plane by using the Gamow Hartree-Fock basis. This basis treats bound, outgoing Gamow resonant and non-resonant continuum states on an equal footing. Carbon and oxygen isotopes have been calculated with chiral effective field theory two- and three-nucleon forces, giving well descriptions of both bound and resonant excited states. The halo structure of the Borromean nucleus 22C is clearly seen by the density calculation, in which continuum s-waves play a crucial role. Further, we predict low-lying resonant excited states in 22C.
        Speaker: Dr 柏山 胡 (北京大学)
        Slides
      • 1:50 PM
        利用多普勒位移法和中心位移法分别测量45Ti和105Pd的能级寿命 20m
        原子核的能级寿命直接与跃迁概率相关,从寿命的研究中可以了解原子核的结构信息。为深入理解45Ti激发态的能级结构,我们在兰州重离子加速器上的TL2终端上利用12C(36Ar, 2pn)反应布居了该核的激发态,并利用HPGe探测阵列测量退激的γ射线。由于45Ti在生成时刻具有较大的飞行速度,致使在靶子前角和后角探测器测到的γ射线具有不同方向的多普勒展宽或位移。我们将利用该多普勒效应并结合LINESHAPE程序来提取45Ti低位激发态的能级寿命。在寿命的研究中,禁戒跃迁问题也是一个研究热点。以105Pd为例,第一个5/2+态主要源于中子d5/2壳层轨道,而第一个7/2+态主要源于中子g7/2壳层轨道,两个能级间的跃迁构成了l禁戒跃迁。为更清楚地认识两个能级的组态成分,我们在北京串列加速器上通96Zr(12C, 3n)反应并利用LaBr和HPGe探测器对105Pd 7/2+态的能级寿命进行了测量。基于LaBr探测器对光子信号响应相对较快的特性,我们采用中心位移法对数据进行了分析。
        Speaker: Dr 广顺 李 (中科院近代物理研究所)
        Slides
      • 2:10 PM
        Variation approach for pair determination in nucleon pair approximation 20m
        In this talk, we would like to suggest a pair-condensation variation approach, which can be a priors and quantitative guide for NPA calculations. Such variation has particle-number conservation, and thus can more accurately describe transitional nuclei, which the NPA is mostly applied to. It also includes all the two-body-configuration degrees of freedom. Therefore, it works for asymmetric deformed nuclei and is enabled to estimate the importance of negative-parity collective pairs. We also propose that such a variation has three self-consistent symmetries. We perform a trial calculation for $^{132}$Ba, which is a typical transitional nucleus. The proposed variation approach is expected to improve the NPA calculation for $^{132}$Ba, as we have demonstrated. In detail, the variation more efficiently establishes the $\gamma$ softness of this nucleus, by imposing pairing correlation. This reveals the ability of our variation approach to describe the asymmetric deformation. It suggests $SD$ pairs, the neutron $H$ pair, and proton $G$, $I$ pairs for the NPA calculations. Following NPA calculations successfully and self-consistently describe the yrast level scheme and the $I=10$ backbending with lower energy. We also explain why negative-parity pairs seem to work for the backbending, but are still not recommended within the framework of our variation. We also observe a rough positive correlation between the pair weights in optimized pair condensation with cranking, and the pair number expectation values of the eigenstates in the following NPA calculations, which provides preliminary evidence on the validity of our variation approach.
        Speaker: Dr 杨 雷 (西南科技大学)
        Slides
      • 2:30 PM
        通过能级寿命测量研究$^{76}$Br的手征及八极关联效应 20m
        通过熔合蒸发反应$^{68}$Zn($^{12}$C,1p3n),束流能量为66MeV,布居了$^{76}$Br的高自旋态,更新了$^{76}$Br已知的能级纲图[1]。本次工作建立了三条转动带,共发现了2个新能级,14条新跃迁,利用DSAM测量了8个能级的寿命,得到对应能级的约化电磁跃迁几率。我们将两条正宇称带组态指定为$\pi$$g_{9/2}$$\otimes$$\nu$$g_{9/2}$,负宇称带组态指定为$\pi$($f_{5/2}$,$p_{3/2}$)$\otimes$$\nu$$g_{9/2}$。对于两条正宇称带,通过对其能级能量、B(M1)和B(E2)的比较,建议其为一对手征双重带。本次工作还观测到了正负宇称带间的6条增强的E1跃迁,将$^{76}$Br中的B(E1)值与已经报导存在八极关联的$^{124}$Ba[2]、$^{125}$Ba[2]、$^{124}$Cs[3]的比较,结果表明$^{76}$Br中可能存在着八极关联效应。 参考文献: [1]Q. Pan et al., Nuclear Physics A 627 (1997) 334-348. [2]P. Mason et al., Phys. Rev. C 72, 064315 (2005). [3]K. Selvakumar et al., Phys. Rev. C 92, 064307 (2015). [4]: https://s2.ax1x.com/2019/08/20/mJlrqS.png
        Speaker: Mr 文政 许 (山东大学(威海)空间科学与物理学院)
        Slides
      • 2:50 PM
        Ab initio chiral three-body force in resonance and continuum 20m
        Three-nucleon force and continuum play important roles in reproducing the properties of atomic nuclei around driplines. In this work, we have developed the chiral three-nucleon force within the continuum Berggren representation. Bound, resonant and continuum states are treated on equal footing in the complex-momentum Berggren space. We choose neutron-rich oxygen isotopes as the test ground. The oxygen isotopes have been well studied experimentally, with the neutron dripline determined. Recent experiments have gone beyond the neutron dripline of the oxygen chain. The calculations were performed with the Gamow shell model, well reproducing the properties of oxygen isotopes around the neutron dripline. The chiral three-nucleon force was dissected by analyzing the contributions of the 2π exchange,1π exchange and contact terms.
        Speaker: Mr 远卓 马 (School of Physics, and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China)
        Slides
      • 3:10 PM
        Systematic study of α-decay half-lives based on Gamow–like model with a screened electrostatic barrier 20m
        In the present work we systematically study α-decay half-lives of Z>51 nuclei using the modified Gamow-like model which includes the effects of the centrifugal potential and electrostatic shielding. For the case of even-even nuclei, this model contains two adjustable parameters: the parameter a related to the screened electrostatic barrier and the radius constant r0, while for the case of odd-odd and odd-A nuclei, it is added a new parameter i.e. hindrance factor h which is used to describe the effect of an odd-proton and/or an odd-neutron. Our calculations can well reproduce the experimental data. In addition, we use this modified Gamow-like model to predict the α-decay half-lives of seven even-even nuclei with Z=120 and some un-synthesized nuclei on their αdecay chains.
        Speaker: Mr Jun-Hao Cheng (University of South China)
        Slides
    • 1:30 PM 3:30 PM
      S2: 核反应、核天体物理 科学会堂101

      科学会堂101

      华中师范大学

      武汉
      Conveners: Dr Zhiyu Sun (Institute of Modern Physics, CAS) , Prof. 伟力 孙 (北京应用物理与计算数学研究所)
      • 1:30 PM
        高密对称能探测相关理论研究 20m
        宇宙里面的剧烈天文事件,如超新星爆发导致的中子星形成,双中子星并和导致的重元素的产生,引力波及伽马射线暴发射等都与致密天体有关。而致密天体通常认为主要是非对称高密核物质。所以研究非对称高密核物质性质,如高密核物质状态方程或高密对称能,能够增加人类对宇宙剧烈天文事件的理解。然而,实验室往往不能直接给出高密核物质状态方程的有关信息,通常由实验数据与输运理论模型计算比较才能得出高密核物质状态方程的信息。结合国际研究前沿,围绕近物所大科学装置CSR及在建HIAF上相关物理目标,汇报最近几年在利用重离子碰撞探测高密对称能方面取得的一些系统性理论研究工作。
        Speaker: Prof. 高产 雍 (中国科学院近代物理研究所)
        Slides
      • 1:50 PM
        高电荷态离子的寿命研究 20m
        近年来,高电荷态离子的衰变研究得到了广泛的关注。这些研究的主要动机之一是星体核合成过程是在高温条件进行的,而在这个过程中原子都处于高电离状态。与中性原子的半衰期相比,高电荷态离子的半衰期会有较大的改变。在实验上测量高电荷态离子的核衰变率是具有挑战性的,因为它需要1)产生高电荷离子,2)存储时间足够长,3)灵敏地测量其衰变。在兰州重离子加速器冷却储存环(HIRFL-CSR)上,用等时性质量谱仪已经开展了多次高电荷态离子的质量和寿命测量实验。 基于HIRFL-CSR上的等时性质量谱仪,研究高电荷态离子在实验环(CSRe)的存储寿命。高电荷态离子由初级束流112Sn35+轰击9Be靶产生,经过放射性束流线RIBLL2的筛选后注入到等时性设置的实验环CSRe中,并利用安装在实验环中的飞行时间探测器测量离子每次经过探测器的时刻。由于离子信号在实验环中最后一个信号的时刻即认定为是该单个离子的损失时刻或是该单个离子的存活时间。通过大量的单个离子的存活时间,可以计算得到离子在储存环的存活寿命。从而能进一步地测量寿命为微秒量级核素的寿命。这可以完善短寿命核素半衰期的测量方法,从而有助于人们对于高电荷态离子衰变的认识与理解,对于人们更好地理解新的衰变机制和天体环境中的元素核合成过程也有着重要的意义。
        Speaker: Dr 奇 曾 (东华理工大学核科学与工程学院)
        Slides
      • 2:10 PM
        Shannon information entropy and its applications in heavy-ion collision physics 20m
        In this talk, we will focus on the applications of Shannon information entropy (SIE) methods in heavy-ion collision (HIC) physics. The main contents of this talk are based on our recent review published on Progress in Particle and Nuclear Physics, which introduce the basic idea of SIE and related observables to HIC physics. Reference: [1] C.W. Ma, Y.G. Ma, Progress in Particle and Nuclear Physics, 99 (2018) 120.
        Speaker: Dr Chun-Wang Ma (Henan Normal University)
        Slides
      • 2:30 PM
        Exploring nuclear dissipation properties at large deformations 20m
        $\qquad$Currently, a survey of dissipation properties in fission has attracted a wide attention [1,2]. While the presaddle dissipation [3,4] has been well determined by confronting theoretical predictions with measured data, few studies are devoted to strongly constraining the strength of postsaddle dissipation. Because the deformation dependence of the nuclear dissipation is a key input for applying stochastic approaches to describe fission data of excited nuclei, how to accurately get information of dissipation at large deformations become very urgent. Based on the Langevin model, we calculate the evolution of postsaddle particle multiplicities of heavy $^{240}$Am nuclei with the postsaddle dissipation strength. It is found that the sensitivity of these particles to the postsaddle dissipation strength is significantly enhanced at high excitation energy and high angular momentum. Moreover, we compare the postsaddle emission as a function of the postsaddle dissipation strength under the conditions of (high excitation energy, low angular momentum) and (low excitation energy, high angular momentum). It is shown that the former type of conditions not only significantly enhances the influence of dissipation on particle evaporation but also substantially increases the sensitivity of light charged particles to the postsaddle dissipation strength. These findings suggest that on the experimental side, to precisely probe the postsaddle dissipation strength by measuring particle emission, in particular with light charged particles, heavy-ion collisions at intermediate energies could be an optimal way to yield highly excited heavy fissioning nuclei [5]. In a recent work, we discuss the important effect of backstreaming on probing postsaddle dissipation with light multiplicity [6]. Reference [1] K. H. Schmidt et al., Rep. Prog. Phys. 81, 106301 (2018). [2] A. N. Andreyev et al., Rep. Prog. Phys. 81, 016301 (2018). [3] J. Tian, N. Wang and W. Ye, Phys. Rev. C 95, 041601 (2017)(R). [4] N. Wang and W. Ye, Phys. Rev. C 97, 014603 (2018). [5] N. Wang and W. Ye, Phys. Rev. C 98, 034614 (2018). [6] N. Wang and W. Ye, submitted for publication.
        Speaker: 宁 王 (东南大学物理学院)
        Slides
      • 2:50 PM
        近垒及垒下能区32S+144,154Sm熔合裂变实验研究 20m
        重离子熔合裂变现象的研究有助于理解重离子核反应运动学的演化过程,同时也为人工合成超重核提供重要的理论支撑。而有关非平衡裂变模型,如形变方向相依的准裂变模型[1]以及低角动量相依的预平衡裂变模型[2]均与入射道紧密相关。因此为了研究入射道对裂变的影响开展了近垒及垒下能区32S+144,154Sm(144Sm:β2=0.087;154Sm:β2=0.340;)熔合裂变实验研究。 实验分为熔合蒸发与裂变两部分。在中国原子能科学研究院HI-13串列加速器的R60°管道上开展了32S+144,154Sm的熔合蒸发激发函数的测量。束流32S实验室系能量为122.44--161.14 MeV。运用静电偏转板对出射产物进行预分离,紧随其后的是由两个微通道板(MCPs)探测器与四分硅探测器(QSD)组成的ToF-E望远镜,用来鉴别蒸发残余核。用对称置于θlab=18°的四个Si(Au)探测器对熔合蒸发残余截面做相对归一,同时也可以监视束流位置。在澳大利亚国立大学(ANU)串列加速器上开展了32S+144,154Sm体系裂变实验。束流32S实验室系能量为138.20--181.76 MeV。使用三块多丝正比计数器(MWPCs)符合测量抽取裂变碎片的质量、出射角度和能量信息。 由于裂变实验数据目前还未分析完成,故用PACE2输出的熔合蒸发成分与裂变成分比值对实验抽取的熔合蒸发激发函数归一到熔合激发函数,并用CCFULL程序对其进行分析。对于32S+154Sm反应体系,在考虑靶核2+,4+,6+,8+转动态和弹核2+双声子振动态时能够很好的重现实验数据。对于32S+144Sm反应体系,由于144Sm靶含有一定成分的Sm同位素杂质,其影响在垒下能区非常明显。在祛除了靶核同位素的影响后,CCFULL的拟合结果显示,当弹核、靶核均考虑2+双声子振动态时,计算结果能很好的重现垒上能区的数据,但低估了垒下能区的实验数据。若靶核再添加3-单声子振动态,则高估了垒下能区的实验数据。 [1] D. J. Hinde et al, Phys. Rev. Lett. 74, 1295 (1995). [2] Z. H. Liu et al, Phys. Lett. B 353, 173 (1995).
        Speaker: Mr 东玺 王 (中国原子能科学研究院)
        Slides
      • 3:10 PM
        240MeV/u能量下15C单质子敲出反应 20m
        **摘要:**丰中子核$^{15}\mathrm{C}$的质子分离能显著高于中子分离能($\mathrm{S_p}-\mathrm{S_n}=19.86\mathrm{MeV}$),呈现出强的同位旋不对称性。测量了$^{15}\mathrm{C}$于240MeV/u能量下在碳靶上的单质子敲出截面,并将实测反应截面与壳模型及程函近似联合得到的理论反应截面进行了比较,得到了实验反应截面与理论反应截面的比值。该比值与约80MeV/u能量下得到的实验-理论反应截面比的系统规律相一致。 **关键词:**敲出反应;深束缚核子;反应截面
        Speaker: 亦轩 赵 (中国科学院近代物理研究所;中国科学院大学核科学与技术学院;兰州大学核科学与技术学院)
        Slides
    • 1:30 PM 3:30 PM
      S3:中高能核物理 9号楼9409

      9号楼9409

      华中师范大学

      武汉
      Conveners: Xin-Nian Wang (Central China Normal University) , Prof. 汉中 张 (Central China Normal University)
      • 1:30 PM
        Nuclear force is a QCD duplication of QED molecular force 20m
        The prevailing idea about nuclear force is due to meson exchange, either phenomenological one boson exchange model or chiral perturbation effective theory both describe the NN interaction data quite well. However they can not explain a long standing fact, as emphasized by Bohr and Mottelson in their Nuclear structure book, the nuclear force is quite similar to molecular force except the energy and length scale. In addition they are hard to describe the hadron interaction beyond the meson production energy region , i.e, 150 MeV higher than NN threshold. In recent years lattice QCD improve their calculations of NN interaction directly from quark-gluon structure. However it is also hard for lattice QCD to explain why nuclear force is similar to molecular force. We extend the Gell-Mann quark model from hadron spectroscopy to hadron-hadron interaction, where we introduce the quark delocalization between quarks confined in different hadrons, similar to electrons delocalization between different atoms. This model describe the vast amount of NN inteaction data as well as the meson exchange model, describe the nucleon-hyperon interaction as well as the SU(3) extension of the phenomenological one boson exchange model. It predicts the "inevitable dibaryon d*", a hadron binding energy scale tight bound six quark system, which had been discovered by WASA-at-COSY collaboration through comprehensive measurements. Predicting the existence of nuclear scale binding N-Omega dibaryon, which had been confirmed by Japenese lattice QCD calculation and STAR collaboration N-Omega scattering data proved attraction between N and Omega. It describes the pJ/psi pentaquark states well and predicting there must be J^p=1/2^- resonance. It also predicts all discovered pJ/psi resonances should be negative parity ones. The most important one is up to now it is the only one model which explains why the nuclear force is similar to the molecular force because it shows the nuclear force is a QCD duplication of QED molecular force.
        Speaker: Prof. Fan Wang (Nanjing University)
      • 1:50 PM
        Tau decay and some interesting applications 20m
        First I will present an novel approach on tau decay recently developed, using the basic weak interaction and angular momentum algebra to relate the different processes. The formalism also leads to a different interpretation of the role played by G-parity in these decays. We compare our results with experiment and other theoretical approaches for rates and invariant mass distributions and make predictions for unmeasured decays [1]. Then some interesting applications will be presented, including the polarization amplitudes and final state interaction on different decays: a) We applied the above novel approach to investigate the different polarization amplitudes on tau decay within the Standard Model. We also extend the formalism to a case that can account for different models beyond the Standard Model. We find one magnitude sensitive and useful to test different models beyond the Standard Model[2]. b) The above developed novel approach was further applied to study the final state interaction: (1) The triangle mechanism for the decay $\tau^- \to \nu_\tau \pi^- f_0(980)$ was studied with $f_0(980)$ decaying into $\pi^+ \pi^- $ and find a narrow peak in the $\pi^+ \pi^-$ invariant mass distribution, in which we explicitly filters $G$-parity states. Similarly, we also study the triangle mechanism for the decay $\tau \to \nu \pi^- a_0(980)$, with the $a_0(980)$ decaying into $\pi^0 \eta $. Our prediction of find final branching ratios for $\pi^- f_0(980)$ and $\pi^- a_0(980)$ of the order of $4 \times 10^{-4}$ and $7 \times 10^{-5}$, respectively, which are within present measurable range. Experimental verification of these predictions will shed light on the nature of the scalar mesons and on the origin of the ``$a_1(1420)$" peak observed in other reactions [3]. (2) We further make some predictions for the decay $\tau \to \nu_\tau P A$, with $P$ a $\pi$ or $K$ and $A$ an axial-vector resonance $b_1(1235)$, $h_1(1170)$, $h_1(1380)$, $a_1(1260)$, $f_1(1285)$ or any of the two poles of the $K_1(1270)$, in which explicitly filtering different $G$-parity states. we evaluate the vector-pseudoscalar amplitudes within the chiral unitary theory, where the axial-vector resonances were obtained as dynamically generated from the VP interaction. We make predictions for invariant mass distribution and branching ratios for the channels considered [4]. Experimental verification of these predictions will shed light on the nature of these scalar mesons and axial-vector resonance states. References [1]L. R. Dai, R. Pavao, S. Sakai and E. Oset, $\tau^- \to \nu_{\tau} M_1 M_2$, with $M_1, M_2$ pseudoscalar or vector mesons, Eur. Phys. J. A 55 (2019) 20 [2]L. R. Dai and E.Oset, Polarization amplitudes in $\tau^- \to \nu_{\tau} V P$ decay beyond the standard model, Eur. Phys. J. A 54 (2018) 219 [3]L. R.Dai, Q. X. Yu and E. Oset, Triangle singularity in $\tau^- \to \nu_\tau \pi^- f_0(980)$ ($a_0(980)$) decays, Phys. Rev. D 99 (2019) 016021 [4]L. R .Dai, L. Roca and E. Oset, $\tau$ decay into a pseudoscalar and an axial-vector meson, Phys. Rev. D 99 (2019) 096003
        Speaker: Prof. Lianrong Dai (Liaoning Normal University)
        Slides
      • 2:10 PM
        Dilepton and direct photon results at RHIC-STAR 20m
        A primary goal of relativistic heavy-ion physics is to study the fundamental properties of the created hot and dense medium. This medium is expected to emit thermal radiation in the form of dileptons and direct photons. Once produced, dileptons and direct photons traverse the medium with minimum interactions. This makes them ideal electromagnetic probes of the medium evolution by selecting different kinematics. In this talk, we will present the dilepton and direct photon results at RHIC-STAR. The $e^{+}e^{-}$ pair mass distributions compared to hadronic cocktails and the direct virtual photon $p_T$ spectra compared to model predictions will be shown. These results are derived from the STAR beam energy scan phase I program. In addition, the low-$p_T$ $e^{+}e^{-}$ pair production in hadronic heavy ion collisions will be presented. Physics implications and opportunities will be discussed.
        Speaker: Dr CHI YANG (Shandong University)
        Slides
      • 2:30 PM
        Tale of coherent photon products: from UPC to HHIC 20m
        The coherent photon-nucleus and photon-photon interactions has been studied in detail to probe the gluon distribution in nucleus and to test QED via relativistic heavy-ion collisions. These kind of interactions are traditionally thought to be only exist in ultra-peripheral collisions (UPC), where there is no hadronic interactions. Recently, significant excess of $J/\psi$ yield and dielectron pair production at very low transverse momentum ($p_{T} <$ 0.3 GeV/c) were observed by the ALICE and STAR collaborations in peripheral A+A collisions, which points to evidence of coherent photon products in hadronic heavy-ion collisions (HHIC). The possible survival of photoproduced $J/\psi$ and electron pair merits theoretical investigations, which are currently rare on the market. In this talk, I will review on the recent experimental and theoretical progress on the coherent photon induced reactions from UPC to HHIC.
        Speaker: 王妹 查 (中国科学技术大学近代物理系)
        Slides
      • 2:50 PM
        Thermodynamics and susceptibilities of isospin imbalanced QCD matter 20m
        We study the thermodynamics and the susceptibilities of quark matter in the framework of two-flavor Nambu-Jona-Lasinio model at finite isospin chemical potential and temperature. Isospin number density, normalized energy density and trace anomaly are shown to be in good agreement with the available lattice data as well as with the results from chiral perturbation theory at zero temperature. We also study how susceptibilities depend on the isospin chemical potential and on temperature. We find a peak for the chiral, pion, and isospin susceptibilities at the critical isospin chemical potential, $\mu_I^c(T)$, at the boundary of the phase transition between the normal and pion superfluid phase. Moreover, temperature makes the transition from normal to pion condended phase smoother. We also note that the pion susceptibility always remains zero in the normal phase while it is finite in the superfluid phase.
        Speaker: Dr 振烟 陆 (ITP, CAS)
        Slides
      • 3:10 PM
        Clustering structure effect on Hanbury-Brown-Twiss correlation in $^{12}$C + $^{197}$Au collisions at 200 GeV 20m
        Through $^{12}$C + $^{197}$Au collisions at $\sqrt{s_{NN}} =$ 200 GeV using a multiphase transport (AMPT) model, the azimuthal angle dependences of the Hanbury Brown-Twiss (HBT) radii relative to the second- and third-order participant plane from $\pi$-$\pi$ correlations are discussed. Three initial geometric configurations of $^{12}$C, namely three-$\alpha$-cluster triangle, three-$\alpha$-cluster chain and Woods-Saxon distribution of nucleons, are taken into account, and their effects on the correlations are investigated. We find that the ratio of the third-order to the second-order HBT radii is quite sensitive to different configurations of $^{12}$C. In addition, this work presents the hadronic rescattering time evolution of the azimuthally dependent HBT radii. From the present study, one can learn that the HBT correlation from identical particles at freeze-out is able to provide the information of different initial configurations as collective flow proposed before.
        Speaker: Mr Junjie He (Shanghai Institute of Applied Physics)
        Slides
    • 1:30 PM 3:30 PM
      S4:探测器和电子学及应用技术 科学会堂301

      科学会堂301

      华中师范大学

      武汉
      Conveners: Prof. Jifeng Han (Sichuan University) , 邦角 叶 (USTC)
      • 1:30 PM
        全吸收型BaF2探测装置的中子屏蔽准直体和中子吸收体的研究 20m
        中子俘获反应截面数据在核天体物理研究、核反应堆设计与核能开发利用中具有非常重要的意义。中国原子能科学研究院已经建造完成了我国第一套的全吸收型BaF2探测装置(Gamma Total Absorption Facility, GTAF),采用瞬发γ测量法,精确测量中子俘获反应截面。中子源是利用HI-13串列加速器产生的脉冲化质子束,通过7Li(p, n)7Be反应建立的。为了有效降低周围环境材料和探测器上产生的散射中子本底,约束中子束流的形状,设计了中子屏蔽准直体。使用MCNP 模拟程序模拟计算了中子和γ射线在几种主要的屏蔽材料中的输运过程,并通过模拟计算确定了屏蔽准直体的加工材料和几何尺寸。为了吸收待测样品产生的散射中子,需要在探测器球壳内部放置中子吸收体,同时吸收体材料还要尽可能的减少对γ能谱的影响。通过MCNP的模拟结果得到了比较理想的设计方案,满足在线开展中子俘获反应截面测量的实验要求。
        Speaker: Dr Qiwei Zhang (China Institute of Atomic Energy)
        Slides
      • 1:50 PM
        Application of Fast Neutron Activation Analysis in Food Safety 20m
        The 14 MeV neutron activation analysis method based on portable D-T neutron generator is used in various industrial and research areas such as oil well logging, online detection of coal elements and neutron radiography. Flour and flour products are the staple food of China, especially the northern residents.However, there are also unscrupulous manufacturers who make a lot of talc powder into the flour, which seriously endangers people's health. The chemical formula of talc is Mg3\[Si4O10](OH)2while the major elements of flour are H, C, O, N. The content of talc in flour can be measured by counting characteristic γ ray produced by (n, p) reaction of 14 MeV neutrons with 28Si and 24Mg. The samples were irradiated for 1 hour and the measurement time was divided into two sections: the first 10 minutes for 1779 keV produced by 28Al and the following 1 hour for 1369/2754 keV produced by 24Na. 3-inch NaI(Tl) detector and 2-inch LaBr3(Ce) detector were used to measure characteristic gamma rays at the same time. 3-inch NaI(Tl) detector was better in measurement because 3-inch NaI(Tl) is superior to 2-inch LaBr3(Ce) detector in detection efficiency and background radiation interference. When the neutron yield of D-T neutron generator is 1.32 × 107 n∙s-1, the linear correlation coefficient between talcum content and characteristic peak counts reaches 99%. The optimal measurement method is that the sample mass thickness is set to 5.86 g·cm-2, and 1779 keV peak is measured with 3-inch NaI(Tl) detector. At this time, the minimum relative standard deviation for multiple measurements to the same sample is 2.07%, and the low limit of detection is 0.07%.
        Speaker: Dr 旭 许 (College of Physics, Jilin University)
        Slides
      • 2:10 PM
        PALS测量技术在放射性活化不锈钢中的应用 20m
        核结构材料(如RPV钢及核反应堆用不锈钢)的辐照脆化一直是研究者关注的基础科学问题之一。反应堆中高剂量的中子辐照会使材料中形成大量的缺陷及缺陷团,导致位错运动受阻,最终影响材料的机械性能。并且,核结构材料中往往含有微量的钴、锰和铯等元素。这些元素经中子照射后,会通过核反应转化成$^{60}Co$,$^{54}Mn$和$^{137}Cs$等放射性核素,进而导致材料带有不同活度的放射性。正电子湮没寿命谱(PALS)测量方法常用来表征材料中缺陷类型的数量、缺陷类型及缺陷浓度,是定量、定性研究原子尺度缺陷的重要手段。应用该技术研究核结构材料中微观缺陷的早期演化机理,对核结构材料机械性能的评估具有重要的实验指导意义。但是含有高活度放射性的核材料,由于其自身释放的伽马射线的干扰,会影响对正电子在材料中寿命地准确测量。 本文设计了一种“三重符合”正电子寿命谱测量系统,可应用于含有不同活度、不同放射性核素核材料的测量。该系统包含常规正电子寿命测量系统中的起始探测器和停止探测器,分别用来探测放射源$^{22}Na$释放的、与正电子同时产生的1.28 MeV伽马光子,和正电子湮没后释放的其中一个0.511 MeV湮没光子。除此之外,系统还包含一个符合探测器,用来探测另一个湮没光子。本设计中选用的 “TAC + SCA” 符合单元,会精确地选择出三个探测器同时都探测到相应射线时的有效湮没事例,这样就排除或减弱辐射伽马光子的影响。并且,根据样品的放射性活度,SCA可灵活调节符合时间窗。符合精度可从常规符合单元的百纳秒量级提升到纳秒甚至皮秒量级,显著降低了偶然符合的概率。实验中以$^{60}Co$放射源模拟核材料中的放射性背底,分别利用常规正电子寿命测量系统和“三重符合”系统测量了标准样品Ni的寿命。结果显示,常规测量系统会受到$^{60}Co$放射性的干扰,导致测得的正电子在Ni中的寿命值偏小;而“三重符合”测量系统可有效去除该放射性背底的影响,测得的正电子在Ni中的寿命与强度均与无$^{60}Co$干扰时常规系统的测量值相当。
        Speaker: 福雁 刘 (中国科学院高能物理研究所)
        Slides
      • 2:30 PM
        基于SERF联合原子磁强计和钐钴自旋源寻找新的自旋相关相互作用 20m
        季伟 粒子物理学标准模型是迄今为止被广泛验证的模型,但是它仍然不能解释很多 现象,包括强CP破缺问题,正反物质不对称问题以及暗物质问题。所以从实验上检验标准模型,并且探寻超出标准模型的新物理吸引了大家的广泛兴趣,其中一个新的领域是探寻新的超出四种基本相互作用的相互作用力。这些新的相互作用力的传播粒子可能是暗物质的候选者,如轴子等。本文研究重点是基于两费米子之间的自旋与/或速度相关的奇异相互作用力(第五力),他们可能不满足宇称守恒,或者时间反演守恒,或者两者都不满足。 本工作首次提出了使用无自旋交换驰豫(SERF)联合原子磁强计和纯铁包被的 SmCo5(ISSC)磁铁自旋源探测第五力的方法。本工作设计了两组用纯铁包裹钐钴磁铁构成的高密度的电子自旋源,通过这种独特设计的结构,纯铁可以有效的将钐钴磁铁的漏磁屏蔽,并且由于钐钴和纯铁的自旋和轨道磁矩比例的差异,整个结构仍然有高密度的净电子自旋产生。本实验以 97.7% 的置信水平对 5 种形式的自旋和速度相关的奇异力在 0.5 m - 1 km的力程范围内作出了新的限制。对其中一项,我们的实验结果在 0.5 m - 10 km 的力程范围内比世界上已知最好的结果灵敏度提高 11 个量级以上。
        Speaker: Wei Ji (Tsinghua University)
        Slides
      • 2:50 PM
        EJ299-33A 塑料闪烁体性能测试及 Geant4 模拟研究 20m
        EJ299-33A塑料闪烁体是近些年研发的具有中子脉冲形状辨别(PSD)能力的新型塑料闪烁体,它的能量和时间分辨能力、脉冲形状分辨能力、响应矩阵等方面的性能一直备受瞩目。本文使用相同体积($\phi$2"$\times$2")的EJ299-33A塑料闪烁体探测器和BC501A液体闪烁体探测器,两个探测器分别使用了CAEN公司生产的集成DPP-PSD固件的DT5720B和DT5730B波形数字采样器以及COMPASS数据采集软件进行数据分析和处理,因此实验分为四组。利用标准伽马放射源($^{60}Co$、$^{137}Cs$、$^{22}Na$),对四组实验系统进行了电子等效能量刻度。同时利用PuC中子源,对四组实验系统的脉冲形状辨别能力进行了分析。研究表明,由于DT5730B具有较高的数据采集效率,所以含有DT5730B的实验组的脉冲形状辨别情况较好;除工作电压外其他条件相同的情况下,BC501A探测器的$n-\gamma$鉴别能力比EJ299-33A探测器较强。
        Speaker: Mr Dexing Wang (Inner Mongolia University For The Nationlities)
        Slides
      • 3:10 PM
        加速器中子源大厅内散射中子分布的模拟研究 20m
        徐子虚 曲国峰 王艺舟 李敏 周茂蕾 刘东 刘星泉 林炜平 韩纪锋† 辐射物理及技术教育部重点实验室,四川大学原子核科学技术研究所,成都 610064 加速器中子源可在较宽能量区间内产生单能中子,单能中子可广泛应用于中子反应截面测量、中子探测器校准、辐射生物学效应等领域。在加速器中子源大厅内产生单能中子的同时,中子会与周围环境发生相互作用而发生散射现象,散射中子可能会使实验产生误差甚至严重影响实验结果。 本文针对四川大学原子核科学技术研究所2×3MV串列加速器中子源大厅进行模拟研究。采用MCNP5对能量为0.2-20MeV的各向同性单能点中子源,在其平面内不同位置处的散射率进行模拟计算。直射中子通量随距离的增加按平方反比规律衰减,散射中子通量随距离的变化基本保持不变。离中子源越近,散射率越低;随着距离的增加散射率上升的速度先快后慢,在靠近墙壁时散射率上升曲线逐渐趋于平缓。一般情况下:源中子能量越低,散射率越高;源中子能量越高,散射率越低。当源中子能量大于1MeV时,散射率开始呈现下降趋势;源中子能量大于7MeV后,散射率进入坪区。能量为0.4 MeV和1 MeV的源中子散射率最高,10 MeV和15 MeV源中子散射率最低。 散射中子的产生主要来自其与墙壁的相互作用,空气的贡献在大多数情况下都可以忽略。中子与物质相互作用的宏观散射截面随中子能量变化曲线与散射率随源中子能量的变化曲线有良好的对应关系,即可用宏观散射截面来解释散射率随源中子能量变化的模拟结果。同时,弹性散射截面远大于非弹性散射截面,因此弹性散射起主导作用。当源中子能量较高时,总散射截面较小,因此其散射率也较低;但此时更高的非弹性散射截面会使得每次相互作用后中子更容易大量损失能量,因此其散射中子中的慢中子成分更多。通过在墙壁表面附上一层中子慢化吸收材料,可以有效降低散射率。例如,5cm的含硼聚乙烯(10% B4C)可以使散射率降低约40%左右。 国家自然科学基金(批准号:11575121)资助的课题
        Speaker: Mr Zixu Xu (Key Laboratory of Radiation Physics and Technology, Ministry of Education; Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, P. R. China.)
        Slides
    • 3:30 PM 4:00 PM
      茶歇 30m
    • 4:00 PM 6:00 PM
      S1: 核结构 科学会堂201

      科学会堂201

      华中师范大学

      武汉
      Conveners: 小红 周 (impcas) , 燕 李 (中科院上海应用物理研究所)
      • 4:00 PM
        New ground-state band energy formula for transitional nuclei 20m
        In the work done by Brentano et al.[1], a two parameter formula for yrast energies in soft rotors or transitional nuclei was proposed, that is $E=\frac{1}{\Im_{0}(1+{\alpha}I+{\beta}E)}$I(I+1)$$, where the moment of inertia depends linearly on spin I and excitation energy E, but it was not pointed out by them how it was deduced, we tend to believe that their formula lacks a clear physical significance, so in the present work a new formula for soft rotors or transitional nuclei is tried to derive. In the variable-moment-of-inertia (VMI) model[2], the following expression for the energy of the state with spin I is yielded: \begin{equation} $E_{I}=\frac{I(I+1)}{2\Im_{I}}[1+\frac{I(I+1)}{4C\Im_{I}^{3}}]$ \end{equation} In the limit of very soft nuclei, Eq. (1) then becomes \begin{equation} $E_{I}({\sigma}\rightarrow\infty)=\frac{3}{4}\frac{I(I+1)}{\Im_{I}}=\frac{1}{\frac{4}{3}{\sigma}^{\frac{1}{3}}[I(I+1)]^{\frac{1}{3}}\Im_{0}}I(I+1)$ \end{equation} where ${\sigma}=\frac{1}{2C\Im_{0}^{3}}$. On the other hand, when discussing the rotation-vibration coupling energy spectrum in the rotation-vibration model (RVM), an approximate expression for the effective moment of inertia has ever been obtained as follows: \begin{equation} $\Im_{eff}=C_{1}+C_{2}E_{I}$ \end{equation} Experimental data on many large deformed nuclei indicate that the linear relationship between the effective moment of inertia and the excitation energy is fairly well established. For transitional nuclei between spherical and deformed limits where neither the vibrator nor rotor limit is very apt. In the present work, a new formula is thus proposed which is tried to fit the level energies of ground-state bands in this kind of nuclei[3]. The basis of this expression is simple: it is the ideal rotor expression \begin{equation} $E=$\frac{1}{\Im(I,E)}$I(I+1)$ \end{equation} but where the moment of inertia depends linearly on expression $(I(I+1))^{\frac{1}{3}}$ of spin I and excitation energy E. That is \begin{equation} $\Im(I,E)=\Im_{0}(1+{\alpha}(I(I+1))^{\frac{1}{3}} +{\beta}E)$ \end{equation} where ${\alpha}$ and ${\beta}$ are adjustable parameters and $\Im_{0}$ sets the overall scale. This moment of inertia is the linear superposition of Eq. (2) and Eq. (3). References [1]P. von Brentano, N. V. Zamfir, R. F. Casten et al., Phys. Rev. C69, 044314(2004) [2]M. A. J. Mariscotti, G. Scharff-Goldhaber, and B. Buck, Phys. Rev. 178, 1864(1969) [3]Shuifa Shen, Yupeng Yan, Jiejie Shen, Jing Song, Mengyun Cheng, Lijuan Hao, arXiv:1710.06986
        Speaker: Prof. Shuifa Shen (Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences)
      • 4:20 PM
        Structural changes and lineshape investigation in 101Pd isotope 20m
        The Doppler Shift Attenuation method has been used to deduce the lifetimes in some of the excited states of $^{101}Pd$. Doppler broadened lineshapes are analyzed for the decaying γ-rays in the band via the nuclear reaction $^{92}Zr({12}C, 3nγ)^{101}Pd$ at a beam energy of 48.8 $MeV$. The beam was delivered by the HI-13 Tandem accelerator at China Institute of Atomic Energy (CIAE), Beijing. The present work aims at the lifetime re-investigation of the γ- levels in νh$_{11/2}$ band, and comparison with the neighboring Pd-isotopes. Theoretical investigations performed in the vicinity of Pd-isotopes have described the systematics well, which indicates an evolution of shape along with involvement of triaxiality. Further the Interacting boson model (IBM) and Triaxial projected shell model (TPSM) based theoretical calculations are demanded to confirm and validate the structural change.
        Speaker: Dr Aman Rohilla (Institute of Modern Physics, Chinese Academy of Sciences)
        Slides
      • 4:40 PM
        Ab initio resonance and continuum Gamow shell model: applied to calcium isotopes up to beyond dripline 20m
        Based on the realistic nuclear force of the high-precision CD-Bonn potential, we have performed comprehensive calculations for neutron-rich calcium isotopes using the Gamow shell model method (CGSM) which includes resonance and continuum. The GSM calculations well produce the binding energies and single-neutron separation energies of the calcium isotopes, predicting that $^{57}$Ca is the last bound odd isotope and even-even $^{70}$Ca is the dripline nucleus in calcium chain. Resonant states are predicted, which provides useful information for experiments on particle unstability in neutron-rich calcium isotopes. The evolutions of the shell structure around the neutron numbers of *N* = 32, 34 and 40 in the calcium chain are understood via the calculations of effective single-particle energies and the energies of the first $2^+$ states, as well as two-neutron separation energies. Our calculations support the sub-shell closures in $^{52}$Ca (*N* = 32) and $^{54}$Ca (*N* = 34) and pedict that the *N* = 40 sub-shell closure disappears in calcium chain. The possible shell closure at N=50 and the dripline position at $^{70}$Ca are predicted. Effects from the continuum coupling are discussed.
        Speaker: Dr Jianguo Li (PKU)
        Slides
      • 5:00 PM
        Spectra, densities and reaction cross sections of drip-line nuclei with the Gamow Shell Model 20m
        Nuclei far away from the valley of stability are actively studied at experimental and theoretical levels. Radioactive ion beam accelerators, which can generate nuclei of very large proton-to-neutron ratio, have indeed revealed unusual features. For example, standard nuclear magic numbers can disappear at drip-lines, while others can develop. Due to their small nucleon separation energies, nuclei at drip-lines can present halos in the asymptotic region and nuclear states can be unbound with respect to particle emission. Models developed for well-bound nuclei are no longer sufficient to describe drip-line nuclei. In fact, drip-line nuclei are open quantum systems, whereas nuclei of the valley of stability are closed quantum systems. A nuclear model able to treat drip-line nuclei consistently is the Gamow Shell model (GSM). GSM is a configuration interaction model based on the use of the one-body Berggren basis. The Berggren basis contains bound, resonance and scattering states, so that continuum coupling is present at basis level. Inter-nucleon correlations are taken into account via the use of configuration mixing, so that both structure and reaction degrees of freedom are included in GSM. It is thus the tool of choice to study weakly bound and resonance nuclei. We will present applications of GSM concerning light nuclei. In particular, GSM has been used in a no-core approach with realistic interactions, so that unbound systems bearing A=3-5 nucleons could be precisely studied. When the number of nucleons increase, it is more convenient to use the core + valence nucleon picture. An effective interaction has been fitted in this framework, where the statistical errors of fitted parameters have been assessed. Spectra, densities and correlation densities will be considered. GSM has also been extended to the study of reaction observables. Scattering and radiative capture cross sections of light nuclei involving nucleon and deuteron projectiles will be presented for that matter.
        Speaker: Prof. Nicolas Michel (Institute of Modern Physics, Lanzhou)
        Slides
      • 5:20 PM
        缺中子核素$^{219}$U的$\alpha$衰变精细结构研究 20m
        在重核和超重核区,$\alpha$衰变谱学是了解原子核的衰变性质、获得原子核结构信息以及鉴别新核素和新元素的有力工具。通过重离子熔合蒸发反应$^{40}$Ar+$^{nat}$W,产生了缺中子核素$^{219}$U。目标核产生后从薄靶中反冲出来,根据粒子磁刚度的不同,在谱仪中与大量的本底粒子进行分离并偏转到位于焦平面的探测系统中。利用寻找$\alpha$衰变链的方法对产物进行了寻找和鉴别。实验结果改善了$^{219}$U现有的$\alpha$衰变数据,并观测到两个新的$\alpha$衰变分支,被指认为是从$^{219}$U的基态到子核$^{215}$Th第一、第二激发态的跃迁。最后对*N*=127偶奇核的$\alpha$衰变及其相应*N*=125子核低激发态的系统性进行了讨论。
        Speaker: Mr 明明 张 (近代物理研究所)
        Slides
      • 5:40 PM
        对超越平均场波函数进行变分的方法研究 20m
        根据量子力学,原子核能谱及波函数应通过求解薛定谔方程得到。对于轻核,这容易做到 。但对于中重核,满空间壳模型计算异常困难,人们只能采用近似方法给出近似波函数。显然 ,平均场近似最简单,可描述整个核区。但所得近似解与哈密顿量精确解差距较大。为此,人 们基于平均场,发展了各种形式的超越平均场方法,以改善波函数的近似性。超越平均场波函数形式多样,可通过投影方法,生成坐标法,以及组态相互作用等方法获得。这些波函数形式的构建并不难,但难点在于:在给定的超越平均场波函数形式下,如何获得最优化的波函数。即对超越平均场波函数进行变分,使之尽可能接近壳模型精确解。 近年来,我们一直致力于研究如何通过变分,得到最优化的超越平均场波函数。最近,我们利用数学上的柯西交错定理,首次严格证明了对于某一量子体系中的任意能级,近似值总是高于精确值这一普遍现象。而在一般量子力学教科书中,这一结论只针对基态而言。基于这一新认识,我们提出了新的变分算法,实现了超越平均场波函数的进一步充分优化。在实际应用中,我们选取投影波函数,并对其充分优化(即投影后变分)。计算表明,该方法可以给出很好的壳模型近 似。此外,我们还将投影波函数进行较大幅度简化,使得投影后变分方法能够轻松计算任意高自旋态。 参考文献: 【1】New algorithm in the variation after projection calculations for non-yrast nuclear states. Jia-Qi Wang, Zao-Chun Gao, Ying-Jun Ma and Y. S. Chen. PHYSICAL REVIEW C 98, 021301(R) (2018)
        Speaker: 早春 高 (中国原子能科学研究院)
        Slides
    • 4:00 PM 6:00 PM
      S2: 核反应、核天体物理 科学会堂101

      科学会堂101

      华中师范大学

      武汉
      Conveners: 建军 何 (中国科学院国家天文台) , 景东 包 (北京师范大学)
      • 4:00 PM
        Alpha-cluster formation and decay in nuclei 20m
        We present a microscopic calculation of α-cluster formation in heavy nuclei by using the quartetting wave function approach. The intrinsic structure of the α-like cluster and the center-of-mass motion of the quartet are analyzed. The α-cluster formation is found to be sensitive to the interplay of the mean field felt by the α-cluster and the Pauli blocking as a consequence of antisymmetrization. The striking feature of α-cluster formation probability across the major shell closures of 82 protons and 126 neutrons is reproduced.
        Speaker: Prof. Xu Chang (Nanjing University)
        Slides
      • 4:20 PM
        Decay studies of nuclei far from β stability line 20m
        The β-delayed γ-ray spectroscopy of neutron-rich 123,125Ag isotopes is investigated at the Radioactive Isotope Beam Factory of RIKEN, and the long-predicted 1/2− β-emitting isomers in 123,125Ag are identified for the first time[1]. With the new experimental results, the systematic trend of energy spacing between the lowest 9/2+ and 1/2− levels is extended in Ag isotopes up to N = 78, providing a clear signal for the reduction of the Z = 40 subshell gap in Ag towards N = 82. To study the β-delayed neutron decay of nuclei far from β stability line, a new beta-delayed neutron detection system working with the continuous beam mode has been built at Peking University and tested with radioactive ion beams[2]. This detection system has been applied to study the β-delayed neutron decay of nuclei around the ‘island of inversion'. To explore the spectroscopy of 18Mg by its four-proton decay to 14O, an experiment was performed at NSCL. The goal of the experiment was to study the energy level and the internal proton correlations of 18Mg, which is further beyond the proton-drip line than the previously well-known two-proton radioactive nucleus 19Mg. The secondary beam of 20Mg was produced by fragmenting 24Mg from the CCF on a 9Be target and purified in the A1900 fragment separator. 18Mg was produced by a two-neutron knockout reaction on another 9Be target in the S800 target chamber. Protons were detected by a silicon (S4) and cesium iodide (CsI) array, and the 14O residues were analyzed by a newly made scintillator fiber array and the S800 spectrometer. Ref. [1]Z.Q. Chen, Z.H. Li, H. Hua, H. Watanabe, C.X. Yuan et al., Physical Review Letters 122, 212502 (2019); [2]C.G. Wang, X.Q. Li, R. Han, Z.H. Li a, H. Hua et al., Nuclear Inst. and Methods in Physics Research, A940, 83–87(2019)
        Speaker: Prof. Hui Hua (Peking University)
        Slides
      • 4:40 PM
        共振γ射线下的197Au(γ,n)196Au反应截面测量 20m
        ---------- 中子嬗变在放射性核废料处理中发挥着重要作用,但也有一些原子核如135CS、90Sr等不适合用于中子嬗变。光中子核反应为这些特殊的原子核提供了一种可能的解决方案。在此背景下,测量光中子反应截面是非常有用的。从(p,γ)共振反应放出的准单能γ射线可以用来研究光致核反应。在前面的工作中,我们测量了Eγ= 9.17MeV下的197Au(γ,n)196Au反应截面。本项工作中,我们将利用7Li(p,γ)8Be反应所产生的17.6MeV的γ射线研究197Au的(γ,n)反应,并用活化法测量其反应截面。
        Speaker: 婉莎 杨 (å)
        Slides
      • 5:00 PM
        Study of the complete fusion of the 7Li + 96Zr system at near-barrier energies 20m
        The measurements of complete fusion cross sections for 7Li + 96Zr have been performed at the HI-13 Tandem Accelerator of the China Institute of Atomic Energy (CIAE) in Beijing at bombarding energies from 16 to 30 MeV in steps of 2 MeV by the online γ -ray method. The complete fusion cross sections at above-barrier energies were extracted. A comparison of complete fusion suppression with the existing data for 6Li+ 96Zr with the present results have carried out. The γ rays from 97Zr (1p stripping channel)can be clearly identified.
        Speaker: Mr Hu Shipeng (Shenzhen University)
        Slides
      • 5:20 PM
        用相对论约化R-矩阵理论获取高精度的12C(α,γ)16O 的天体物理S因子和反应率 20m
        求得到准确的(要求误差小于10%)12C(α,γ)16O 的天体物理S因子和反应率(E=0.3 MeV),对于研究天体演化过程极为重要,曾被称为核天体物理研究的‘圣杯’。全世界50多年的努力还没有得到公认的满意的结果,目前除了我们发表的初步结果外,绝大多数的数值精度大于10%。主要原因首先是在天体物理感兴趣的能区(E=0.3 MeV)12C(α,γ)16O的反应截面太小太小,用目前的实验装置不可能直接测量到,只能通过测量高能区的截面和理论分析向低能外推得到。外国理论分析普遍采用的‘R-矩阵-电磁跃迁’模型不宜做global拟合,必然导致多家分析结果误差很大和差别很大。为此,我们创立了‘相对论约化R-矩阵理论’,可以巧妙地将γn+16On(n=0,1,2,3,4)当作复合核2体反应道处理,使用我们自己研制的高精度的‘相对论约化R-矩阵程序’-RAC,采用4类方案,都得到了很好的12C(α,γ)16O 的天体物理S因子和反应率。第一方案是采用近似的电磁跃迁公式,其研究结果已经被分别发表在美国出版的‘物理评论’与‘天体物理’杂志上,其后又不断改进,采用准确的电磁跃迁公式和有差别的数据分析方法,使分析越来越可靠和准确,其误差都小于6%。 与国外同类R-矩阵程序和同类工作相比,RAC和该工作具有以下的特点和先进性。 A. 采用相对论的能量计算公式,可以巧妙地将γn+16On(n=0,1,2,3,4)当作复合核2体反应道处理,为此可以同时分析16O系统中所有反应道的实验数据; B. 采用多道多能级约化R-矩阵公式,可以分析全能区的实验数据,为此可以同时分析16O系统中所有可以利用的实验数据;国外的R-矩阵程序还固守在使用普通的R-矩阵公式; C. 采用严格的广义最小二乘公式和误差传播理论,可以严格地使用实验数据误差信息,为此可以准确地给出所有反应道评价值的协方差矩阵;国外的R-矩阵程序还固守在使用普通的最小二乘公式(日本的学者在尝试使用广义最小二乘公式); D. 采用了多种精密的有特色的数值拟合方法,比如反复迭代,单参数梯度法,智能记忆路径,等等,有可能获得最佳拟合。 最近几年,通过国际合作与学术交流,关于如何使用R-矩阵理论的共识在不断增加。
        Speaker: 振鹏 陈 (清华大学)
        Slides
      • 5:40 PM
        强激光驱动等离⼦体对撞下的2H(d, p)3H反应研究 20m
        核聚变反应是自然界中为恒星提供能量并产生新元素的最重要过程。因此,研究接近真实天体物理条件的全等离子体环境中的反应至关重要。强激光与物质相互作⽤时产⽣的⾼温、⾼压、⾼密的等离⼦体环境,是对天体环境很好的近似,我们使用了神光Ⅱ号装置驱动等离子体对撞的方法研究了2H(d, p)3H反应,用CR-39固体探测器分别记录了K型靶(LiD)、平面靶(LiD)、K型混合靶(LiD,LiH)、平面混合靶(LiD,LiH)发生2H(d, p)3H反应的质子。
        Speaker: yangfan he (China Institute of Atomic Energy, Beijing 102413, China ; School of Physics and Space Sciences, China West Normal University, Nanchong 637002, China)
        Slides
    • 4:00 PM 6:00 PM
      S3:中高能核物理 9号楼9409

      9号楼9409

      华中师范大学

      武汉
      Conveners: Prof. Qun Wang (University of Science and Technology of China) , Xu-Guang Huang (Fudan University)
      • 4:00 PM
        Chiral magnetic effect and anomalous magnetohydrodynamics 20m
        We study relativistic magnetohydrodynamics with longitudinal boost invariance in the presence of chiral magnetic effects and finite electric conductivity. With initial magnetic fields parallel or antiparallel to electric fields, we derive the analytic solutions of electromagnetic fields and the chiral number and energy density in an expansion of several parameters determined by initial conditions. The numerical solutions show that such analytic solutions work well in weak fields or large chiral fluctuations. We also discuss the properties of electromagnetic fields in the laboratory frame.
        Speaker: Shi Pu (University of Science and Technology of China)
        Slides
      • 4:20 PM
        Sensitivity analysis of the chiral magnetic effect observables using a multiphase transport model 20m
        The chiral magnetic effect is a good observable to investigate the topological and electromagnetic properties of the QGP. But the $\gamma$ correlator, a common observable used to detect the CME, contains both contribution from the CME and its background. This observable can not identify the CME from its background. Recently, a new observable of $R_{\Psi_{m}}$ has been proposed, which is expected to distinguish the CME from the background. We apply mixing particles method and shuffling particles method to calculate $R_{\Psi_{m}}$ using a multiphase transport model without or with a percentage of CME-induced charge separation.
        Speaker: ling huang (中科院上海应用物理研究所)
        Slides
      • 4:40 PM
        Electromagnetic field from asymmetric to symmetric heavy ion collision at 200 GeV/c 20m
        Electromagnetic fields produced in relativistic heavy-ion collisions are affected by the asymmetry of the projectile-target combination as well as the different initial configurations of the nucleus. In this study, the results of the electric and magnetic fields produced for different combinations of ions, namely $^{12}$C + $^{197}$Au, $^{24}$Mg + $^{197}$Au, $^{64}$Cu + $^{197}$Au, and $^{197}$Au + $^{197}$Au at $\sqrt{s_{NN}} = 200$ GeV are demonstrated with a multi-phase transport model (AMPT). The configuration of the distribution of nucleons of $^{12}$C is initialized by a Woods-Saxon spherical structure, a three-$\alpha$-clustering triangular structure or a three-$\alpha$-clustering chain structure. It was observed that the electric and magnetic fields display different behavioral patterns for asymmetric combinations of the projectile and target nuclei as well as for different initial configurations of the carbon nucleus. The major features of the process are discussed.
        Speaker: yilin cheng (Shanghai Institute of Applied Physics, Chinese Academy of Sciences)
        Slides
      • 5:00 PM
        Collectivity in heavy ion collisions at RHIC-STAR 20m
        The flow harmonics (vn) especially, the first order (directed flow, v1) and the second order (elliptic flow, v2) are the sensitive probes to study QCD matter formed in heavy-ion collisions. Hydrodynamic models suggest that the double sign change of v1 slope (dv1/dy) at midrapidity for net baryon as a function of √sNN is a signature of the first-order phase transition. The light nuclei and strange hadrons might be more sensitive to the early EoS due to heavier mass and smaller hadronic interaction cross section, respectively. Because of the different sensitivity of strange particles to hadronic phases, the mass ordering of vn is expected to be violated between proton and φ meson in the low pT range (pT <1.5 GeV/c). Furthermore, a comprehensive v1 and v2 measurement of light nuclei, multistrange, strange and non-strange hadrons enable a precision study of the coalescence sum rule, which will lead to better understanding of particle production mechanism. A measurement of charged hadron v1 as a function of pseudorapidity allows one to test the validity of limiting fragmentation and also compared with other experimental data. In this talk, we will present new measurements of vn for deuterons, identified and charged hadrons in Au+Au collisions at √sNN = 7.7, 11.5, 14.5, 19.6, 27, 39 and 54.4 GeV. The collision energy, centrality and transverse momentum dependence of these particles are discussed and compared to model calculations.
        Speaker: 梳苏 施 (Central China Normal University)
        Slides
      • 5:20 PM
        $\sqrt{s_{NN}}=5-11$ GeV 正反质子椭圆流劈裂的平均场势效应 20m
        最近,STAR合作组在相对论重离子对撞机(RHIC)的一期束流能量扫描实验(BES-Ⅰ)中观测到了正反粒子的椭圆流($v_{2}$)劈裂现象,质子与反质子之间的椭圆流差随着入射能量$\sqrt{s_{NN}}$ (净重子密度)的升高(降低)而减小。对此不同的理论组利用不同的模型给出了不同的解释。 基于极端相对论量子分子动力学(UrQMD)模型,我们通过为预形成粒子考虑一个类似于已形成粒子之间的平均场势修正来部分实现预形成粒子之间的相互作用,由此为碰撞早期提供更大的压强以及粒子间更紧密的相互关联使得反质子可以更早地被挤出火球区域。我们的计算结果可以较好的描述实验测得的质子的椭圆流以及质子与反质子之间的椭圆流差及相对椭圆流差。同时我们将能区拓展到NICA能区($\sqrt{s_{NN}}=5\sim11$ GeV),计算结果显示质子与反质子的椭圆流差依赖于中心度和快度窗口的选取。随着中心度的降低以及快度窗口的缩小,质子与反质子的椭圆流差表现出较强的能量(净重子密度)依赖性。我们期待在即将进行的实验(BES-Ⅱ,CBM,NICA 以及HIAF)上看到这种流劈裂的中心度、快度、能量的依赖性。
        Speaker: Dr Pengcheng Li (Lanzhou University&Huzhou University)
        Slides
      • 5:40 PM
        小系统中关于初始动量关联对末态集体流影响的研究 20m
        小系统中的长程方位角关联的起源问题是目前相对论重离子碰撞领域的热点之一。目前的研究主要集中 于如下争论:即这种长程关联导致的集体流是由碰撞开始前的初始动量各向异性导致的,还是由于反映 初始几何形状的末态相互作用导致的。为了具体厘清小系统中集体流的成因,我们基于多相输运模型, 通过可控的方式引入所谓“初始流”,从而在输运模型中同时研究初始和末态相互作用效应。我们的研究 结果表明末态观测到的集体流,原则上会同时包含上述两种贡献,在高多重数区域,初始流的贡献有限, 但是在低多重数区域,初始流的贡献则尤为显著。因此,对于小系统中观测到的集体流不能只是孤立地 认为是由几何形状响应导致的,也应该考虑初始效应的贡献。
        Speaker: Maowu Nie (Shandong University)
        Slides
    • 4:00 PM 6:00 PM
      S4:探测器和电子学及应用技术 科学会堂301

      科学会堂301

      华中师范大学

      武汉
      Conveners: Prof. BiTao Hu (Lanzhou University) , 兴忠 曹 (IHEP)
      • 4:00 PM
        Progress of TMSR structural materials research 20m
        As one of the six most promising Generation IV fission reactors, the Molten Salt Reactor (MSR) will be able to not only produce electric power, but allow for re-burning, deep burning, and nuclear transmuting of radioactive waste.The structural materials of MSR will be subjected to the extreme environments, i.e., high temperature, high neutron doses and corrosive coolant. Thus, the research and development of qualified materials is very important for the development of MSR technology. In this presentation, the research and development progress of two key structural materials of molten salt reactor, high temperature nickel-based alloy and ultrafine grain nuclear graphite, and their comprehensive performance evaluation (mechanical properties, molten salt corrosion properties, neutron irradiation properties) will be introduced. The acquisition of a large number of material engineering data has laid a solid foundation for the construction of our experimental reactor. In addition, we have carried out a lot of research on the key scientific issues in the research of molten salt reactor materials, such as the service behavior of materials under extreme environments and related damage mechanisms. our latest research findings will be also briefly reported in this presentation.
        Speaker: Prof. Hefei Huang (Shanghai Institute of Applied Physics, Chinese Academy of Sciences)
      • 4:20 PM
        SiC-Al2O3-ZrO2复合陶瓷中的氦行为研究 20m
        采用2.0 MeV的He离子对放电等离子烧结法(SPS)制备的SiC-Al2O3-ZrO2复合陶瓷进行了不同参数的离子辐照,辐照温度分别为室温和800℃,剂量范围为1E16-1E18 He/cm2,通过透射电子显微镜对不同参数辐照样品的氦泡尺寸和数量进行了观测,结果显示:1. 不同参数辐照后的样品中均产生了大量氦泡,但不同物相成分中的氦泡行为有明显不同:Al2O3晶粒中氦泡均匀分布,相同辐照深度下不同Al2O3晶粒中的氦泡尺寸和浓度无明显区别;ZrO2晶粒中氦泡存在部分区域分布较少的现象,ZrO2和Al2O3晶界处有氦泡聚集;SiC晶粒处无明显氦泡。2.辐照温度为800℃时,相同辐照深度区域中,辐照剂量高的样品中氦泡尺寸要大于辐照剂量低的样品中氦泡尺寸,表明入射He离子剂量越高,样品中的氦泡越容易聚集长大;3.相同辐照深度下,高温辐照样品中的氦泡尺寸要明显大于室温样品中的氦泡尺寸,表明高的辐照温度能够促进氦泡生长。4.相同辐照参数下,SiC-Al2O3-ZrO2复合陶瓷中的氦泡尺寸要明显小于Al2O3-ZrO2对照样品中氦泡尺寸,同时对比两种材料样品表面辐照剥落情况,发现SiC-Al2O3-ZrO2复合陶瓷抗He离子辐照能力优于Al2O3-ZrO2,对复合陶瓷中的辐照机理进行了对比分析。
        Speaker: Dr 亚滨 朱 (中国科学院近代物理研究所)
      • 4:40 PM
        基于非支配混合差分进化的核设施屏蔽智能设计方法 20m
        加速器、核反应堆等核设施需要建造有效的辐射屏蔽系统以保证工作人员、公众及环境安全。辐射屏蔽设计的目标是使外部剂量保持在合理的尽可能低的水平,同时尽量最小化屏蔽体的重量、体积以及成本等,是一个复杂的多目标优化问题。传统辐射屏蔽系统设计一般基于经验调整系统参数进行迭代设计,存在过于依赖专家经验且系统设计方案常过于粗略的问题。本文基于中子输运设计与安全评价软件系统SuperMC“超级蒙卡”,融合经典的非支配排序遗传算法NSGA-II和混合差分进化算法发展了非支配混合差分进化的多目标智能核设计方法
        Speaker: Mr Guangyao Sun (Institute of Nuclear Energy Safety Technology, CAS)
      • 5:00 PM
        Hastelloy N合金中氦泡与位错环在Xe+He离子先后辐照条件下的协同效应研究 20m
        熔盐反应堆作为第四代核反应堆系统,以其高的安全性、可靠性及效率而受到全世界的关注。Hastelloy N 合金由于具有良好的耐氟化物熔盐腐蚀性能,被认为是最优的熔盐堆候选结构材料。在熔盐反应堆运行过程中,离位损伤和核嬗变反应产生的氦同时存在,二者相互作用,将加速弱化结构材料的服役性能。本研究在650 ºC条件下分别用单束Xe 离子、单束He离子以及Xe + He两种离子先后辐照Hastelloy N合金样品,Xe离子和He离子的辐照剂量分别为1.1×1015 ions/cm2和3×1016 ions/cm2。利用透射电子显微镜和纳米压痕仪对辐照后材料的微观结构和力学性能进行表征分析,结果表明:对于Xe + He两种离子先后辐照的样品,微观结构与硬度的变化均存在协同效应。
        Speaker: 继召 刘 (中科院上海应用物理研究所)
        Slides
      • 5:20 PM
        Multi-purpose Active-target Time-projection-chamber for nuclear astrophysics Experiments (MATE) at IMP 20m
        New and next generation RIB facilities provide new insight into the nuclear structure and reaction dynamics of exotic nuclei. However, many of the most interesting species are always produced with very low intensities. Active target Time Projection Chamber is one powerful device with several significant features, including 4π acceptance of the reaction products, full detection efficiency and high sensitivity, and an event-by-event reconstruction in three dimensions. This enables the use of TPC to break through beam limitation and study nuclei very far away from stability. One novel TPC is being developed in a collaboration at IMP. Our primary goal is to study astrophysically important fusion reactions and key (α,p) reactions in the X-ray bursts.
        Speaker: Mr Zhichao Zhang (IMP,UCAS)
        Slides
      • 5:40 PM
        Optimization design of a Si-based betavoltaic battery using Ni-63 source 20m
        A theoretical study of the optimization and simulation of a betavoltaic battery composed of a p-n junction converter and a Nickle-63 isotope source is presented. The self-absorption of β particles in the Ni-63 radioisotope film and the energy deposition of β particles in the semiconductor converter are investigated by the Monte Carlo simulation. The relationships between doping concentrations and basic parameters such as depletion region width, minority carrier diffusion length and leakage current of the p-n junction are discussed through the calculation formulas. On the other hand, the output performance of the battery are obtained through COMSOL Multiphysics modeling software, such as the short-circuit current density, open-circuit voltage, maximum output power density and energy conversion efficiency. Finally, the optimal design of the betavoltaic battery are given, including the thickness of the source, the p-n junction depth, the doping concentrations in the p-type and n-type regions.
        Speaker: Mr 人洲 郑 (吉林大学)
        Slides
    • 6:00 PM 9:00 PM
      晚餐 3h 桂苑宾馆

      桂苑宾馆

      华中师范大学

      武汉
    • 8:30 AM 10:10 AM
      S1: 核结构 科学会堂201

      科学会堂201

      华中师范大学

      武汉
      Conveners: Prof. Hui Hua (Peking University) , 景彬 陆 (吉林大学)
      • 8:30 AM
        山东大学(威海)开展的核物理研究 20m
        本报告将介绍山东大学威海校区核物理交叉科学研究中心从事的原子核精细谱学,核天体物理,核探测器和高能核物理研究。重点介绍在原子核手征对称性,八极关联和反磁转动等方面的研究进展及未来研究规划。
        Speaker: Dr Shouyu Wang (School of Space Science and Physics, Shandong University at Weihai)
        Slides
      • 8:50 AM
        Ba和Ce同位素中的集体运动实验研究进展 20m
        近二十年来,对基于稳定三轴形变的集体运动的研究,取得了突飞猛进的发展。其中近半的实验工作是对130质量区的近稳定线原子核开展的。我们最近在意大利Legnaro和南非iThemba开展了两次实验工作,分别研究了$^{130,131}$Ba和$^{133,134}$Ce的高自旋态。在$^{131}$Ba中,发现了包含六条转动带的多重手征带结构。其中,四条正宇称带之间存在复杂的带间跃迁,可能是赝自旋对称性和手征对称性共同作用的结果,而一条负宇称带与全部四条正宇称带之间都存在E1跃迁,可能是受八极关联的影响。这可能是实验上第一次发现包含手征对称性、赝自旋对称性和八极关联的结构。在$^{131}$Ba,$^{133}$Ce,以及我们参与的另一项实验工作研究的$^{135}$Nd中,都在低自旋区域发现了向$h_{11/2}$晕带退激的转动带。通过线性极化测量和角分布测量,我们发现摇摆运动可能是$^{133}$Ce中转动带的成因。这可能是实验上首次发现基于一个空穴组态的摇摆现象。在$^{130}$Ba中发现了长椭、扁椭、三轴形变的共存。尤其对于$\nu h^2$组态,除了长椭带、扁椭带之外,还发现了一个沿主轴以外的倾斜方向转动的倾斜带,这是130质量区首次发现该现象。此外,我们还建立了$^{130}$Ba中K同质异能态以上的能级结构,并提取了g因子。
        Speaker: Dr 松 郭 (中国科学院近代物理研究所)
        Slides
      • 9:10 AM
        Investigating K$^{\pi}$ = 2$^{-}$ Band in $^{248}$Cf 20m
        Transcurium nuclei are believed to exhibit strong triaxial-octupole correlation with Y$_{32}$ shape by theory. Such an effect is expected to be strongest at Z = 98. Microscopically, around the Fermi surface of Z = 98 and N = 150 both protons and neutrons have available pairs of orbitals that could be strongly coupled by octupole interaction. Indeed, low-lying 2$^{-}$ states have been identified in a few corresponding even-even nuclei. In this presentation, we report on newly observed K$^{\pi}$ = 2$^{-}$ octupole band in $^{248}$Cf nuclei to high-spin states. The pair of bands are unearthed from data of $^{208}$Pb + $^{249}$Cf inelastic/transfer experiment performed at Argonne National Lab. Techniques and results will be discussed in the context of the physics of neighboring isotones and isotopes within the framework of RASM calculations.
        Speaker: Dr Yuan Qiu (Shanghai Jiao Tong University)
      • 9:30 AM
        $^{81}$Kr奇A核中三准粒子转动带的实验研究 20m
        基于南非iThemba国家实验室的AFORDITE探测阵列,利用熔合蒸发反应$^{82}$Se($^{4}$He,4n)$^{81}$Kr布居了$^{81}$Kr高自旋态。依据$\gamma$-$\gamma$符合关系和强度平衡,建立了$^{81}$Kr新的纲图。通过提取$\gamma$跃迁的ADO系数和线性极化值确定了纲图中能级的自旋和宇称。本工作相比于1986年L. Funke等人[1]的结果,新发现了20条能级、62条跃迁和两条转动带。 为了探究$^{81}$Kr中转动带的内禀结构,提取了转动带的能级能量、旋称劈裂、带交叉频率、转动惯量、角动量顺排、约化电磁跃迁几率等物理量。通过分析,尝试指定了它们的组态,并且初步认为在奇A核$^{81}$Kr中观测到了一对基于$\pi$$g_{9/2}^{2}$$\otimes$$\nu$$g_{9/2}$三准粒子组态的手征双重带。进一步的理论分析正在进行中。 ![谱][3] 参考文献: [1] L. Funke *et al.*, Nucl. Phys. A 455 (1986) 206-230 [3]: https://s2.ax1x.com/2019/08/20/mJKHIA.png
        Speaker: Ms Lin Mu (山东大学(威海)空间科学与物理学院,山东 威海,264209)
        Slides
      • 9:50 AM
        Tl同位素链中候选手征核的理论探索 20m
        我们利用绝热与组态固定的三轴相对论平均场理论[1]研究了铊同位素中的手性。当前的计算在奇奇核$^{192,194,196,198}$Tl与奇偶核$^{193,195,197}$Tl中获得了具有明显三轴形变与高-j粒子空穴组态的极小点。在这些组态与形变的基础上,上述原子核可能形成手征双重带。进一步,我们发现在$^{192,193,194,195,196,197,198}$Tl中可能存在多手征带。由于实验上已经在$^{193,194,198}$Tl发现了手征双重带,$^{195}$Tl中发现了多手征带,我们期待接下来的实验可以去探索$^{192,196,197}$Tl中的手性以及上述核素中的多手征带来验证我们的预言。 ![][0] 图:奇奇核$^{192,194,196,198}$Tl和奇A核$^{193,195,197}$Tl的实验激发能与指定的组态如上图所示。实验数据取自文献[2-8],其中实验已经报道了$^{193,194,195,198}$Tl中的手征双重带与多手征带。基于三轴相对论平均场理论计算得到的候选手征组态总结在图的右侧。 [1] J. Meng, J. Peng, and S. Q. Zhang et al., Phys. Rev. C 73, 037303 (2006). [2] E. A. Lawrie, P. A. Vymers, and J. J. Lawrie et al., Phys. Rev. C 78, 021395 (2008). [3] P. L. Masiteng, E. A. Lawrie, and T. M. Ramashidzha et al., Eur. Phys. J. A. 50, 119 (2014). [4] J. Ndayishimye, E. A. Lawrie, and O. Shirinda et al., Acta Physica Polonica B 48, 343 (2017). [5] T. Roy, G. Mukherjee, and Md. A. Asgar et al., Phys. Lett. B 782, 768 (2018). [6] A. J. Kreiner, A. Filevich, and G. Garcia Berrnudez et al., Phys. Rev. C 21, 993 (1980). [7] A. J. Kreiner, M. Fenzl, and W. Kutschera, Nucl. Phys. A 308 147 (1978). [8] H. Pai, G. Mukherjee, and S. Bhattacharya et al., Phys. Rev. C 88, 064302 (2013). [0]:https://s2.ax1x.com/2019/08/20/mJQshR.jpg
        Speaker: 晓 陆 (山东大学(威海))
        Slides
    • 8:30 AM 10:10 AM
      S2: 核反应、核天体物理 科学会堂101

      科学会堂101

      华中师范大学

      武汉
      Conveners: 国运 邵 (西安交通大学) , 德清 方 (fudan)
      • 8:30 AM
        天体能区恒星碳燃烧反应数据的间接测量 20m
        天体核反应12C(12C,α)20Ne是恒星核合成及恒星演化中碳燃烧过程的关键核反应。目前直接测量能量下限只到达2.1MeV,且3.5MeV以下数据具有相当大的不确定性,尤其在核天体物理最感兴趣的伽莫夫能区EG=1.5±0.5MeV直接测量数据至今仍然是空白。特洛伊木马方法能克服直接测量中因库仑位垒抑制带来的根本性困难,得到感兴趣的天体能区反应截面,而且无需外推,从而避免了外推过程中因可能存在低能共振或阈下共振而造成的不确定性。最近,LNS用特洛伊木马方法间接测量到1.5MeV能区有强共振而引发轰动,但所用木马核14N=(12C+d)是强束缚核,是否适合做木马受到质疑。本工作将选用结合能相对较小的16O=(12C+α)作为木马核,通过三体反应12C(16O,α20Ne)α进行间接测量,提取12C(12C,α)20Ne在伽莫夫能区的天体S(E)因子,对数据可靠性进行交叉检验。
        Speaker: Dr 成波 李 (北京市辐射中心)
        Slides
      • 8:50 AM
        17F+58Ni体系在库仑势垒能区的反应机制研究 20m
        在近库仑势垒能区,以中子晕核$^{6}$He为代表的丰中子区体系的反应机制目前已有较为系统的结果。而对于丰质子奇特核诱导的反应机制,目前实验数据仍然十分匮乏,仅有的数据并不自洽。因此,丰质子奇特核体系的反应机制的物理图像仍然非常模糊,亟待深入研究。 有鉴于此,我们在日本东京大学原子核研究中心的CRIB终端上完成了质子滴线核$^{17}$F+$^{58}$Ni体系的完全运动学测量。利用d($^{16}$O,$^{17}$F)n反应,我们在近垒能区产生了43.63, 47.47, 55.72和63.06 MeV 四个能量的$^{17}$F次级束流。为了实现反应产物的完全鉴别,我们研制了一套基于电离室的探测器阵列[1]。实验结果表明,重离子(如$^{17}$F,$^{16}$O等)以及轻反应产物(如p, d, alpha)都能够被清楚鉴别。这是首次在近垒能区的17F的轻靶体系中实现反应产物的完全鉴别。我们得到了$^{17}$F+$^{58}$Ni体系的准弹性散射角分布,并提取了总反应截面。与其它体系的总激发函数比较表明,$^{17}$F具有相对较弱的反应活性;对于得到的$^{16}$O反应产物角分布,利用连续态离散化耦合道算法(CDCC)和观察者模型(IAV 模型)分别进行了计算,结果表明,非弹性破裂(non-elastic breakup)是主要的直接反应机制;通过测量熔合蒸发的p和alpha,进一步提取了$^{17}$F+$^{58}$Ni体系的总熔合截面,根据与参考标准UFF(universal fusion function)的比较表明,该体系的总熔合截面在垒上能区稍有压低,但在垒下能区存在明显的增强现象。$^{17}$F的弱束缚效应对其反应机制的影响还需要进一步的深入考察。 [1] N. R. Ma et. al, EPJA 55, 87 (2019).
        Speaker: Dr Lei Yang (China Institute of Atomic Energy)
        Slides
      • 9:10 AM
        关于晕核的反应机制与结构的实验研究 20m
        弹性散射、破裂反应等直接核反应具有较大的反应截面、是研究奇特原子核结构和核力性质的有效实验手段。本报告将介绍我们团队近几年在RIBLL1上开展的关于Li、Be、B、C等系列丰质子或丰中子同位素核的弹性散射、破裂反应机制相关的实验研究。结合这些实验研究,我们发现了质子晕和中子晕核对直接核反应的影响是有明显区别的,比如质子晕核$^{8}$B与中子晕核$^{11}$Be,价核子的分离能都很小,分别为136keV和502keV,但是它们对弹性散射的影响截然不同。从$^{11}$Be与中重靶的弹性散射看到了库仑势与核势干涉峰被显著削弱的现象,而$^{8}$B却没有。而且,人们对于$^{8}$B破裂反应中的碎片径向分布宽度的解释也存在争议。因此我们需要深入考虑质子晕核与中子晕的区别,需要更多实验研究质子晕核形成的机制和条件。
        Speaker: jiansong wang (H)
        Slides
      • 9:30 AM
        基于新旋转子模型下的钨同位素核子入射散射分析 20m
        钨同位素作为大形变核,不仅在核反应理论研究上具有重要的研究价值;同时其作为材料核,在核工程应用方面也有广泛的应用前景。我们采用新的旋转子模型实现了对钨同位素的核子入射散射分析。旋转子模型包括硬旋转子模型和软旋转子模型。在过去的工作中,通常用硬旋转子模型对钨核进行描述。但是硬旋转子模型只考虑了轴向形变,未考虑原子核非轴对称的伸缩性变化(振动),其对大变形核的描述并不充分。而该旋转子模型中在用硬旋转子模型描述基态转动带的同时,还采用软旋转子结构描述了原子核的非轴形变。另外,新的旋转子模型还考虑了形变半径的修正,使得在钨同位素区域光学势分析中,去除了核半径的质量依赖,从而减少了区域光学势的参数个数。分析结果包括中子总截面,总截面差,散射角分布以及分析本领。其中中子总截面与总截面差的计算结果相比现有的评价库结果有了明显的提高。
        Speaker: Mr zhao xiuniao (Graduate School of China Academy of Engineering Physics)
        Slides
      • 9:50 AM
        重离子碰撞类靶快裂变研究 20m
        原子核裂变过程作为一种大幅度的集体运动模式,自上世纪30年代发现以来就一直受到核物理及核工程等领域科学家的关注。在重离子碰撞诱发原子核裂变的研究中,对于入射束能较低的原子核裂变的研究方法主要包括多种形状参数表征势能面的唯象方法和通过多核子体系描写原子核集体运动的微观动力学方法,这些方法都能较好地描写裂变过程;但是,对于入射束能较高(大于10MeV/u)的原子核裂变,即快裂变,就不能再通过唯象方法进行研究,而只能尝试通过微观动力学方法,如ImQMD模型等。 本工作通过采用改进的量子分子动力学模型(ImQMD)分析了重离子碰撞(40Ar+197Au, b=8 fm)中靶核在20~40MeV/u能量下的快裂变现象。分析得出,快裂变时标在几百fm/c的时间尺度,快裂变的动力学特征由裂变轴的质量不对称性和角分布来描述;在入射束能量较高或表面能量系数较大的情况下,裂变碎片的质量不对称性较大,裂变轴的角分布在束流方向附近呈现出更为明显的峰值,而裂变时间尺度较短,这一明显变化表明,裂变轴角分布可作为探测原子核表面能量系数的敏感探针;分析还得了出裂变碎块平均相对速度位于2.4 cm/ns附近,其与束流能量及表面能系数关系不大,符合统计裂变中的Viola系统性。
        Speaker: 强华 吴 (清华大学)
        Slides
    • 8:30 AM 10:10 AM
      S3:中高能核物理 9号楼9409

      9号楼9409

      华中师范大学

      武汉
      Conveners: Dr Zhongbao Yin (华中师范大学) , Prof. 笙琴 冯 (三峡大学理学院)
      • 8:30 AM
        Exploring the phase transition of strongly interacting matter with density fluctuations 20m
        In this talk, we will discuss the relation between density fluctuations and phase structure of strongly interacting matter. We focus on the phase transition in the high-density region where a non-equilibrium first-order transition possibly be trigged with lower collision energies. On the other hand, we will discuss the QCD phase structure in the presence of an background magnetic field. We will analyze that how the Landau quantization deforms the QCD phase structure and induces the entropy oscillation.
        Speaker: Prof. Guo-yun Shao (Xi'an Jiaotong University)
        Slides
      • 8:50 AM
        Strangeness production and hypernuclear formation in heavy-ion collisions and with hadron induced reactions 20m
        Formation mechanism of hyperfragments with strangeness s=-1 and s=-2 in heavy-ion collisions and with hadron induced reactions was investigated within a microscopic transport model. Dynamics of pseudoscalar mesons and hyperons is modeled within the transport model, in which all possible reaction channels for creating hyperons such as the elastic scattering, resonance production and decay, strangeness exchange reaction and direct strangeness production in meson-baryon and baryon-baryon collisions have been included. A coalescence approach is developed for constructing hyperfragments in phase space and the decay process is described with a statistical approach. It is found that the cascade production is correlated to the kaon formation and the hyperons are created within a broad rapidity region. The production cross sections of nucleonic fragments and hyperfragments weakly depends on the incident momentum. The yields of lambda hyperfragments are the six order of magnitude of cascade hyperfragments.
        Speaker: Prof. 兆庆 冯 (华南理工大学)
        Slides
      • 9:10 AM
        Production of strange particles in jets and the underlying event in pp, p-Pb and Pb-Pb collisions measured with ALICE 20m
        The $p_{\rm T}$ dependence of the baryon-to-meson yield ratio in hadronic and nuclear collisions is sensitive to the collective expansion of the system, the partonic recombination into hadrons, the jet fragmentation and hadronization. In the region 2 < $p_{\rm T}$ < 6 GeV/$c$, this ratio for inclusive yields is significantly enhanced at high multiplicity in small collision systems, such as pp and p-Pb collisions, relative to that at lower multiplicity. However, the origin of the enhancement still remains an open question. In this contribution, we explore the connection between the baryon-to-meson ratio enhancement and jet production via the measurement of the $p_{\rm T}$-differential spectrum of strange and multi-strange particles (${\rm K}_{\rm S}^{0}$, $\Lambda$ and $\Xi$) in pp, p-Pb and Pb-Pb collisions, both inclusively and within energetic jets. The results set new constraints on the particle production mechanisms in jets and provide new insight into the understanding of the origin of flow-like correlations observed in small systems.
        Speaker: Pengyao Cui (Central China Normal University)
        Slides
      • 9:30 AM
        Light (anti)nuclei and (anti)hypernuclei production and characterization in Cu+Cu collisions at $\sqrt{s_{\rm{NN}}}=200$GeV 20m
        Production of light (anti)nuclei ( $\rm d$, $\rm\overline d$, $\rm ^3He$, $\rm^3\overline {He}$, $\rm ^4He$, and $\rm^4\overline {He}$) and (anti)hypertriton nuclei ($\rm ^3_{\Lambda}H$ and $\rm ^3_{\overline \Lambda}\overline H$ ) are investigated using the dynamically constrained phase-space coalescence model based on the final-state hadrons generated by the PACIAE model in Cu+Cu collisions at $\sqrt{s_{\rm{NN}}}=200$GeV. The results show that there is a strong centrality dependence of yields of the light (anti)nuclei and (anti)hypernclei, i.e., their yields decrease rapidly with the increase of centrality, and the greater the mass is, the greater the dependence shows; whereas their ratios of antimatter to matter remain constant as the centrality increases. The coalescence parameter $B_A$ lightly decreases with the increasing of $N_{part}$. In addition, the yields of (anti)nuclei are strongly dependent on the mass of the (anti)nuclei, indicating that the (anti)nuclei produced have mass scaling properties in high-energy heavy-ion collisions. $\rm ^3_{\Lambda}H$ and $\rm ^3_{\overline \Lambda}\overline H$ are compared with $\rm ^3H(^3\overline H)$ and $\rm ^3He(^3\overline {He})$ nuclei. The strangeness population factor $S_3=\rm{({^3_{\Lambda}H}/{^3{He}})/(\Lambda/p)}$ was found to be close to unity, and was compatible with the STAR data and theoretical model calculation, suggesting that the phase-space population of strange quarks is similar with the ones of light quarks and the creation of deconfined high temperature quark matter in Cu+Cu collisions.
        Speaker: Dr Fengxian Liu (China University of Geosciences)
        Slides
      • 9:50 AM
        Hybrid model and \Lambda polarization at 7.7-200 GeV 20m
        In this model, as a physical dynamic approach, AMPT is used to generate initial energy, velocity and net baryon density profile as the initial condition of hydrodynamics. The initial flow plays an important role especially at BES energies, where we find harder transverse momentum spectra of final particles. Based on this model, we also investigated the global and local structure of $\Lambda$ polarization at hydrodynamic freeze-out hyper surface. It could reproduce the global polarization trends and the similar circular structure at finite rapidity region as the pure transport model. We also predict $\Lambda$ polarization as a function of centrality, transverse momentum, rapidity and azimuthal angle at different energies.
        Speaker: Mr Baochi Fu (Peking University)
        Slides
    • 8:30 AM 10:10 AM
      S4:探测器和电子学及应用技术 科学会堂301

      科学会堂301

      华中师范大学

      武汉
      Conveners: Donghai Zhang (Shanxi Normal University) , 洁琼 蒋 (fds)
      • 8:30 AM
        “类汝瓷”的原料特征和微观结构 20m
        汝窑是我国宋代五大名窑之一,它与官、钧、哥、定齐名于世,南宋叶寘的《坦斋笔衡》中有“汝窑为魁”之说。由于烧制宫廷御用汝瓷的时间很短,烧成的青瓷质量上乘,数量有限,到南宋时期已是“近尤难得”的稀世珍品,因其品位很高,具有极其丰富的科技内涵,引起国内外许多陶瓷专家的广泛关注。从1987到2000年,河南省文物考古研究所先后6次对宝丰清凉寺汝窑遗址进行挖掘,发现了汝官窑遗址中心烧造区。从2012到2014年针对汝官窑中心烧造区及四周相关区域进行了3次考古发掘,与以往不同的是,此次发掘一方面出土了一种青釉瓷器,其釉色类似汝瓷,也有天青、青绿和卵青,釉色光亮,玻璃质感强,但玉质感不及汝釉。为了和汝瓷区分,暂将此种瓷器定名为“类汝瓷”。 为进一步探讨不同釉色“类汝瓷”的釉料配方、胎料产地和微观结构是否一致,选取草绿、天青、卵青三种釉色的“类汝瓷”样品30个,用X射线荧光分析(XRF)测量样品中Na2O、MgO、Al2O3、SiO2、P2O5、K2O、CaO、TiO2、MnO、Fe2O3、Cr2O3、ZnO、Rb2O、SrO、Y2O3、ZrO2等16种元素的化学组分,用X射线衍射仪(XRD)和扫描电子显微镜(SEM)分析样品的物相和微观结构,用多元统计分析对XRF数据进行处理,从而得出“类汝瓷”的元素组成特征及它们之间的分类关系,结果表明:草绿、天青、卵青三种样品胎的原料来源一致;不同釉色“类汝瓷”的釉料配方相近,但不完全相同;“类汝瓷”胎样品中未发现长石结构,主要包含莫来石、α-石英和方石英;“类汝瓷”瓷胎胎质较为均匀,有气孔;釉层中有较大的气泡,含有大量的针状或柱状的钙长石晶体和分相结构。
        Speaker: Prof. 维娟 赵 (郑州大学)
        Slides
      • 8:50 AM
        The developments of new types of micro-XRF spectrometer focused by polycapillary optics 20m
        In this presentation, we will rporte the developments of micro-X-ray fluorescenc and micro-X-ray diffractions spectrometers focused by polycapillary optics in our Lab recently. A portable micro energy dispersive X-ray fluorescence spectrometer with Laser Displacement Sensor (LDS) is reported in this paper. Due to irregular or curved surface of archaeological object, the distances between the irradiation spot of sample and exit of polycapillary X-ray optics can vary. In this paper, we employed a LDS in our portable micro-X-ray fluorescence spectrometer to control the distances between the irradiation spot on the sample and the exit of polycapillary X-ray optics in order to decrease the errors caused by the irregular or curved surfaces of samples. In order to test this spectrometer, elemental mapping analyses were carried on with and without LDS on an irregular colored glaze of a piece of curved ancient porcelain, the height difference of two parts of ancient porcelain being nearly 5 mm. From the results, it can be concluded that this spectrometer has potential application prospects in measuring irregular or curved surface of samples. On the other hand, a new type of micro-X-ray diffraction spectrometer is shown also.
        Speaker: Prof. Lin CHENG (Beijing Normal university)
        Slides
      • 9:10 AM
        原子能院加速器质谱研究进展 20m
        原子能院加速器质谱研究进展
        Speaker: 明 何 (中国原子能科学研究院)
        Slides
      • 9:30 AM
        碘化铯带电粒子探测器阵列 20m
        在束 $\gamma$ 谱学是研究原子核结构的重要实验方法。熔合蒸发反应是布居原子核的高自旋态最有效、也是最常用的方法。熔合蒸发反应有众多反应道,得到的 $\gamma$ 能谱混杂着众多生成核的谱线,从中标记特定生成核(尤其是生成量较低时)很困难。 针对熔合蒸发反应中蒸发的 p、$\alpha$ 等轻质带电粒子,本工作设计制作了带电粒子探测阵列,计划和南非 iThemba 实验室 AFRODITE 阵列,以及中国原子能科学研究院的 $\gamma$ 阵列配合使用。它由 64 块 CsI(Tl) 探测单元组成,其中前角 48 块做碗身,后角 16 块做碗盖。该阵列使用 PIN 型光二极管和雪崩光二极管做光信号读出,它们体积较小,使得搭建的阵列能够放在靶室内部使用。 首先使用放射源测试对 $\alpha$ 粒子和 $\gamma$ 射线的鉴别能力,可以得到不同的信号波形如图 [1],使用脉冲形状甄别的方法 \[1\] 可以将其区分,如图 [2]。2017 年,该带电粒子探测阵列在南非 iThemba 实验室 AFRODITE 终端进行的 $^{58}$Ni($^{19}$F, 2p1n)$^{74}$Br 在束 $\gamma$ 谱学实验中使用,可覆盖 20 % 的 4$\pi$ 立体角,如图 [3] 所示。对数字获取记录的信号波形进行脉冲形状分析能够清晰地鉴别出质子和 $\alpha$ 粒子,如图 [4]。下一步,我们计划将其升级,覆盖接近 4$\pi$ 立体角。在光电传感器方面,由于雪崩型光二极管内部增益的温度相关性 \[2\],计划为其增加温度反馈模块;同时也计划测试多像素光子计数器(MPPC)的光读出效果。 ![测试得到的 $\alpha$ 粒子和 $\gamma$ 射线的波形,按信号上升时间由快到慢分别是 $\gamma$ 射线与光二极管相互作用的信号波形,$\alpha$ 粒子与 CsI 晶体相互作用,$\gamma$ 射线与 CsI 晶体相互作用的波形。][1] 图 1: 测试得到的 $\alpha$ 粒子和 $\gamma$ 射线的波形,按信号上升时间由快到慢分别是 $\gamma$ 射线与光二极管相互作用的信号波形,$\alpha$ 粒子与 CsI 晶体相互作用,$\gamma$ 射线与 CsI 晶体相互作用的波形。 ![脉冲形状甄别法可以区分放射源测试中的 $\alpha$ 粒子和 $\gamma$ 射线。][2] 图 2: 脉冲形状甄别法可以区分放射源测试中的 $\alpha$ 粒子和 $\gamma$ 射线。 ![CsI 带电粒子探测阵列和南非 iThemba 实验室 AFRODITE 阵列配合。][3] 图 3: CsI 带电粒子探测阵列和南非 iThemba 实验室 AFRODITE 阵列配合。 ![脉冲形状甄别法可以区分实验中的 $\alpha$ 粒子、质子和 $\gamma$ 射线。][4] 图 4:脉冲形状甄别法可以区分实验中的 $\alpha$ 粒子、质子和 $\gamma$ 射线。 [1]: https://github.com/hxchi/wuhan2019/blob/master/pid3.png?raw=true [2]: https://github.com/hxchi/wuhan2019/blob/master/pid4.png?raw=true [3]: https://github.com/hxchi/wuhan2019/blob/master/sduCsIArray1.jpg?raw=true [4]: https://github.com/hxchi/wuhan2019/blob/master/pid5.png?raw=true 参考文献: [1]: W. Skulski, M. Momayezi, Nucl. Instr. Meth. A 458, 759 (2001). [2]: J. Kataoka, et al. Nucl. Instr. Meth. A 564, 300 (2006).
        Speaker: Xingchi Han (Shandong University)
        Slides
      • 9:50 AM
        碳剥离膜厚度与剥离效率关系的测量 20m
        随着串列加速器的发展,最佳剥离膜厚度得到了广泛深入的研究。大多数研究主要集中在高电荷态铀离子条件下,剥离膜的最佳厚度,多数研究涉及到的剥离膜厚度大于10 ug/cm2。[1,2]碳离子轰击剥离膜的研究则较少。为研究低电荷态碳离子在0~3 MeV 加速电压下最佳剥离膜厚度。主要采用 ETACHA 软件模拟,并结合实验检验。最佳膜厚度主要以电荷剥离效率作为判断依据,同时将会考虑到剥离膜寿命,束流发散度和能量歧离的影响。结果如下:(1) 由模拟条件2 MV电压加速得,如图1所示,C3+的最大剥离效率高于C+和C2+,碳膜在1 ug/cm2、10 ug/cm2和13 ug/cm2左右时,分别对C4+、C5+和C6+的剥离效率最高;(2) 对比了C+、C2+和C3+经2 MV电压加速后穿过5 ug/cm2的碳剥离膜后产生各种碳离子的比例,如图2所示,排除原束流干扰后,实验与模拟符合较好;(3) 模拟了8 MeV碳离子穿过20 ug/cm2碳剥离膜后的出射能量,7.86 MeV;能量离散,8024 eV;位置偏离,0.31 Å。说明碳膜的添加对束流品质影响较小。结果对低能加速器产生高价态高能离子具有一定指导意义。
        Speaker: Mr Wang Yizhou (Institute of Nuclear Science and Tchnology)
        Slides
    • 10:10 AM 10:30 AM
      茶歇 20m
    • 10:30 AM 12:30 PM
      S1: 核结构 科学会堂201

      科学会堂201

      华中师范大学

      武汉
      Conveners: Prof. Bingsong ZOU Bingsong (IHEP, CAS) , 善贵 周 (理论所)
      • 10:30 AM
        New magicity $N=32$ and $34$ due to strong couplings between Dirac inversion partners 20m
        The continuous magic nature at $N=32$ and $34$ in Ca isotopes are illustrated by using the relativistic Hartree-Fock (RHF) Lagrangian PKA1 as referred to recent experiments. It is found that large spin-orbit (SO) splitting of $\nu$2p orbits presents the $N=32$ shell in $^{52}$Ca, whereas significantly reduced $\nu$2p splitting, together with nearly unchanged $\nu$1f one, leads to the magicity $N=34$ in $^{54}$Ca. Such essential changes of the $\nu$2p splitting can be interpreted self-consistently, following the density evolution from central-bumped structures in $^{52}$Ca to the central-flat (proton) and even central-depressed (neutron) ones in $^{54}$Ca. Moreover, it is proved that the dramatic density evolution originates from the strong repulsive interaction between the "Dirac inversion partners" (DIPs) $(\nu2p_{1/2},\nu s_{1/2})$. Finally, we also reveal the mechanism for the appearance of new magicity $N=32$, by analyzing the significant role played by $s_{1/2}$ orbits, which determines the SO spitting of $\nu 2p$ orbits through the strong couplings with the DIP $\nu 2p_{1/2}$. As a result, $^{48}$S is predicted to be the last even isotone preserving the magicity $N=32$ on the proton-deficient side, and together with the predicted proton subshell $Z=16$, it can be also a doubly magic nucleus.
        Speaker: Prof. Wen Hui LONG (School of Nuclear Science and Technology, Lanzhou University, 730000 Lanzhou, China)
        Slides
      • 10:50 AM
        Shape transition with temperature of the pear-shaped nuclei in covariant density functional theory 20m
        The shape evolutions of the pear-shaped nuclei $^{224}$Ra, even-even $^{144–154}$Ba, and even-even $^{286−304}$Cm with temperature are investigated by the finite-temperature relativistic mean field theory with the treatment of pairing correlations by the BCS approach. The free energy surfaces as well as the bulk properties including deformations, pairing gaps, excitation energy, and specific heat for the global minimum of the isotopes are studied. For $^{224}$Ra, three discontinuities found in the specific heat curve indicate the pairing transition at temperature 0.4 MeV and two shape transitions at temperatures 0.9 and 1.0 MeV, namely one from quadrupole-octupole deformed to quadrupole deformed, and the other from quadrupole deformed to spherical. Furthermore, the gaps at $N$ = 136 and $Z$ = 88 are responsible for stabilizing the octupole-deformed global minimum at low temperatures. Similar pairing transition at $T$ ∼ 0.5 MeV and shape transitions at $T$ = 0.5–2.2 MeV are found for even-even $^{144–154}$Ba. A proportional relation between the critical shape transition temperature and the deformation at zero temperature $T_c=6.6\beta(0)$ or $T_c=44A^{−1/3}\beta(0)$ where A is the mass number is found for both octupole shape transition and quadrupole shape transition. Through this study, the formation of octupole equilibrium is understood by the contribution coming from the octupole driving pairs with $\Omega[N,n_z,m_l]$ and $\Omega[N+1,n_z\pm3,m_l]$ for single-particle levels near the Fermi surfaces as it provides a good manifestation of the octupole correlation.
        Speaker: Dr Wei Zhang (Zhengzhou University)
        Slides
      • 11:10 AM
        Quasi-rotational bands observed in very neutron-rich odd-odd $^{64,66}$Mn isotopes at $N \sim 40$ 20m
        Excited states in $^{64,66}$Mn have been studied using in-beam $\gamma$-ray spectroscopy through knockout reactions from radioactive beams of $^{67,68}$Fe, respectively. The level schemes for the two odd-odd Mn isotopes have been established, exhibiting characteristics of quasi-rotational bands. Based on the systematics of the level structures in the lighter odd-odd Mn isotopes, the spin-parity of the levels and a $\pi f_{7/2} \otimes \nu g_{9/2}$ configuration have been proposed for the quasi-rotational bands in $^{64,66}$Mn, extending the quasi-rotational level structure to the most neutron-rich odd-odd Mn isotopes. The observed levels are compared with large-scale shell model calculations in the fpgd shell using the state-of-the-art LNPS effective interaction.
        Speaker: Dr Bing Ding (中国科学院近代物理研究所)
        Slides
      • 11:30 AM
        Non-extensive solution to Cosmological Lithium problem 20m
        Big Bang nucleosynthesis (BBN) theory predicts the abundances of the light elements D, $^3$He, $^4$He and $^7$Li produced in the early universe. The primordial abundances of D and $^4$He inferred from observational data are in good agreement with predictions, however, the BBN theory overestimates the primordial $^7$Li abundance by about a factor of three. This is the so-called ``cosmological lithium problem''. Solutions to this problem using conventional astrophysics and nuclear physics have not been successful over the past few decades, probably indicating the presence of new physics during the era of BBN. We have investigated the impact on BBN predictions of adopting a generalized distribution to describe the velocities of nucleons in the framework of Tsallis non-extensive statistics. This generalized velocity distribution is characterized by a parameter $q$, and reduces to the usually assumed Maxwell-Boltzmann distribution for $q$ = 1. We find excellent agreement between predicted and observed primordial abundances of D, $^4$He and $^7$Li for $1.069\leq q \leq 1.082$, suggesting a possible new solution to the cosmological lithium problem.
        Speaker: Dr Suqing Hou (Institute of Modern Physics, Chinese Academy of Science)
        Slides
      • 11:50 AM
        Z=50附近奇质子核113In的高自旋态研究 20m
        王豪1,马克岩1,陆景彬1,潘昊楠1,杨东1,李剑1,马英君1,杨森1,管弦1,杨清宇1,竺礼华2,吴晓光3,贺创业3,郑 云3,李聪博3,李广生3, (1吉林大学物理学院,长春,130012 2北京航空航天大学,北京,100191 3中国原子能科学研究院,北京,102413) 摘要:本工作通过重离子融合蒸发反应110Pd (7Li,4n)113In布居了奇A核113In的高自旋态,入射束流能量为38MeV和50MeV。对比早期的研究工作,该核的谱学信息被极大的拓展,总计82个新能级,120余条新的γ射线被观测。在此基础上, 4条新的强△I=1转动带被建立,其组态被分别指定为π(g9/2)-1⊗ν(h11/2)(g7/2)-1⊗ν(g7/2)2、π(g9/2)-1⊗ν(h11/2)(g7/2)-1⊗ν(h11/2)2、π(g9/2)-1⊗ν(h11/2)2⊗ν(g7/2)2和π(g9/2)-1⊗ν(h11/2)2⊗ν(h11/2)2。理论上,基于自洽的倾斜轴推转相对论平均场方法(TAC-RMF),对上述△I=1结构进行了理论研究,研究结果表明其具有磁转动的特征。在对△I=2带的研究中,我们也观测到了1条新的△I=2转动带,通过系统学研究及理论计算表明,该结构源于处在g9/2上斜轨道的质子,跨壳激发到具有侵入特性的d5/2轨道,进而该带的组态被指定为πd5/2。此外,先前已知的πg7/2带被拓展到了51/2+能级,由中子g7/2/d5/2拆对顺排引起的上弯被观测。基于倾斜轴推转壳模型计算,该组态带回弯之后的结构被指定为候选的反磁转动带,这也是国内报道的为数不多的几例反磁转动结构。值得一提的是,本工作还首次建立了先前悬空的πh11/2高j侵入带与低激发态之间的多条退激路径,基于新的退激路径,实验上稳固确定了该带的激发能、自旋及宇称,这也为深入系统地研究该组态带的转动特性提供了必要的实验支撑。 基金项目:国家自然科学基金(11775098、U1867210、11475072、11675063、 11405072、); 吉林省科技发展计划项目(20190201137JC、20180520195JH);吉林省“十三五”科学研究规划项目JJKH20180117KJ;中央高校基本科研业务费专项资金项目。
        Speaker: 豪 王 (吉林大学)
        Slides
    • 10:30 AM 12:10 PM
      S2: 核反应、核天体物理 科学会堂101

      科学会堂101

      华中师范大学

      武汉
      Conveners: 小华 李 (N) , 彩万 沈 (N)
      • 10:30 AM
        Comparison between Variational Monte Carlo and Shell Model Calculations of Neutrinoless Double Beta Decay Matrix Elements in Light Nuclei 20m
        Benchmark comparisons between many-body methods are performed to assess of the ingredients necessary for accurate calculation of neutrinoless double beta decay matrix elements. Shell model and variational Monte Carlo (VMC) calculations are carried out for $A=10$ and $12$ nuclei. Different variational wavefunctions are used to evaluate the uncertainties in the {\it ab initio} theory, and fairly small difference is found between the VMC double beta decay matrix element predictions. For shell model calculations, the role of model space truncation, radial wavefunction choices, and short-range correlation are investigated and all found to be important. Based on the detailed comparisons between the VMC and shell model approaches, we conclude that accurate descriptions of neutrinoless double beta decay matrix elements require a proper treatment of both long-range and short-range correlations.
        Speaker: Prof. Xiaobao Wang (Huzhou University)
        Slides
      • 10:50 AM
        Exotic Decays and Reactions of Extremely Proton-rich Nuclei 20m
        With the development of radioactive ion beams (RIBs), reaction and decay studies with exotic nuclei become a hot topic in nuclear physics. In the talk, I would like to mention some recent progresses achieved by our group, mainly on the following two topics: 1) Exotic decays of extremely proton-rich nuclei. Beta-delayed particle decays from 20,21Mg, 22,23Al, 22,23,24Si, 26,27P, 27,28,29S have been measured by the continuous implantation-decay method using silicon arrays and γ-detectors. A lot of new decays have been observed and rich information of β-decay spectroscopy has been obtained. For example, a new βp-decay branch was observed for 20Mg and the 22Si nucleus is identified as new β2p emitter [1]. Moreover, the p and γ emissions from the excited state (1120 keV, 3/2+) of 27P were measured simultaneously in 27S β-decays [2], which is useful to determine the astrophysical reaction rate of 26Si(p,γ)27P and study the nucleosynthesis of 26Al in the Milky Way. 2)Reactions with exotic nuclei. Nucleus-nucleus interaction potential is a start-point to understand the gross feature of nuclear reaction. Due to the limitation of intensity and quality of RIB, it is rather difficult to extract the optical model potentials (OMPs) of exotic nuclear systems by the traditional method of elastic scattering. For this reason, a transfer reaction method was proposed and applied to extract the OMPs of 6He+12C, 64Zn, 209Bi systems via 11B, 63Cu, 208Pb(7Li,6He) reactions [3]. The threshold anomaly behavior has been obtained in the 6He+209Bi system for the first time, showing that the dispersion relation is not applicable for the exotic nuclear systems. Moreover, special processes involving the weakly-bound nature are crucial to understand the reaction mechanism of exotic nuclei. An important task is to understand the breakup effects as well as its mechanism. To this end, a complete-kinematics measurement method was developed and applied in the 17F+58Ni, 89Y, 208Pb and 7Be+208Pb experiments [4]. The processes of elastic scattering, breakup/transfer, and fusion evaporation have been identified successfully. Preliminary results of 17F+58Ni show that the fusion is suppressed at above-barrier energies due to the loss of incident flux while enhanced below-barrier due to couplings to the continuum states. Details will be presented in the conference. [1] X.X. Xu, C.J. Lin, L.J. Sun et al., Phys. Lett. B 766, 312 (2017); Phys. Rev. C 95, 014314 (2017). [2] L.J. Sun, X.X. Xu, C.J. Lin et al., Phys. Rev. C 99, 064312 (2019). [3] L. Yang, C. J. Lin, H. M. Jia et al, Phys. Rev. Lett. 119, 042503 (2017); Phys. Rev. C 96, 044615 (2017); Phys. Rev. C 95, 034616 (2017) [4] G. L. Zhang, G. X. Zhang, C. J. Lin et al., Phys. Rev. C 97, 044618 (2018).
        Speaker: Prof. Chengjian Lin (China Institute of Atomic Energy)
        Slides
      • 11:10 AM
        在近物所开展的弱束缚核弹性散射研究 20m
        近几十年来,对于奇特核的研究获得了研究人员的广泛关注,弹性散射是研究奇特核反应机制及其奇特核结构的理想工具。依托大科学院工程HIRFL(Heavy-Ion Research Facility in Lanzhou)[1],研究人员在兰州放射性束流线(RIBLL)[2]上建立了一套实验方法[3],并开展了三倍库伦势垒能区的丰质子核$^8$B[4], $^{9,10,11}$C[5,6]和丰中子核$^{11}$Be在Pb靶上的弹性散射实验研究。$^8$B最后一个质子的分离能只有138keV,被认为是最有可能具有质子晕的候选核之一,但实验结果表明小的分离能并没有对弹性散射角分布有明显地影响,弹性散射角分布并没有被压低。而对于丰中子核$^{11}$Be,实验结果表明破裂道对弹散道有明显地耦合效应,弹性散射角分布被明显地压低。 参考文献: [1] W. L. Zhan, J. W. Xia, H. W. Zhao et al., Nuclear Physics A 805 (2008) 533c [2] Z. Sun, W. L. Zhan, Z. Y. Guo et al. Nucl. Instr. and Meth. A 503 (2003) 496 [3] Y. Y. Yang, J. S. Wang, Q. Wang et al., Nucl. Instr. and Meth. A 701 (2013) 1 [4] Y. Y. Yang, J. S. Wang, Q. Wang et al., Phys. Rev. C 87 (2013) 044613 [5] Y. Y. Yang, J. S. Wang, Q. Wang et al., Phys. Rev. C 90 (2014) 014606 [6] Y. Y. Yang, X.Liu, J.S.Wang et al., Phys. Rev. C 98 (2018) 044608
        Speaker: Dr 彦云 杨 (Institute of Modern Physics of the Chinese Academy of Sciences)
        Slides
      • 11:30 AM
        Beta-decay studies of extremely proton-rich nuclei from Mg to S 20m
        Extremely proton-rich nuclei 20,21Mg, 22Al, 22,23Si, 26P and 27,28,29S have been produced by fragmentations of 28Si and 32S primary beams impinged on a 9Be target at the HIRFL-RIBLL1 of the Institute of Modern Physics, Lanzhou, China. Beta-decay studies have been performed using silicon arrays [1] and clover-type HPGe detectors and brand new results have been obtained: 1, 20Mg [2], a new proton group was observed and the corresponding excited state in 20Na was proposed; 2, 22Si [3], a charged-particle group at 5600 (70) keV in the decay-energy spectrum was identified experimentally as β-delayed two-proton emission from the isobaric analog state of 22Al. The ground-state mass of 22Si was obtained in the experiment for the first time. Two-proton separation energy for 22Si is deduced to be -108 (125) keV, which indicates that it is a very marginal candidate for two-proton ground-state emission. Moreover, a large mirror asymmetry for the first 1+ excited state of 22Si was observed in comparison with the mirror nucleus 22O. 3,27S[4] and other nuclei, the experimental data are being analyzed and more interesting decays of these nuclei will be investigated in future. For example, proton and gamma emissions from the excited state (1120 keV, 3/2+) of 27P were observed at the same time in the beta decay of 27S in our measurements, which can be used to calculate the astrophysical reaction rate for the 26Si (p, γ) 27P reaction and study the nucleosynthesis of 26Al in the Milky Way. References [1] L. J. Sun, X. X. Xu, C. J. Lin, et al, Nuclear Inst. and Methods in Physics Research A 804, 1–7 (2015). [2] L. J. Sun, X. X. Xu, D. Q. Fang, et al, Phys. Rev. C 95, 014314 (2017). [3] X. X. Xu, C. J. Lin, L. J. Sun, et al, Phys. Lett. B 766, 312 (2017). [4] L. J. Sun, X. X. Xu, C. J. Lin, et al, Phys. Rev. C 99, 064312 (2019).
        Speaker: Dr Xinxing Xu (The Institute of Modern Physics)
        Slides
      • 11:50 AM
        采用色散球型光学势的双幻数核$^{90}$Zr的核子入射散射研究 20m
        本工作采用新的球型色散光学势形式对双幻数核$^{90}$Zr进行了核子散射分析,核子入射能量从1KeV到200MeV。相比于通常所采用的光学势,本工作在实部中所采用的Hartree-Fock势可以给出更合理的定域能量近似形式。 该色散光学势通过色散关系将势的实部和虚部有机的结合,并实现了与Lane方程的自洽,最终可用一套参数同时对$^{90}$Zr中子和质子的弹性散射进行计算,计算结果与实验数据拟合得很好。我们进一步采用该光学势的实部作为壳模型势,对$^{90}$Zr的单粒子束缚态进行了相应研究,得到了合理的拟合结果。
        Speaker: Ms Wenqing Du (Graduate School of China Academy of Engineering Physics)
        Slides
    • 10:30 AM 12:10 PM
      S3:中高能核物理 9号楼9409

      9号楼9409

      华中师范大学

      武汉
      Conveners: Dr Guo-Liang Ma (Fudan University) , Yaxian Mao (Central China Normal University)
      • 10:30 AM
        Quark Gluon Plasma at the Smallest Scale 20m
        In ultra-relativistic collisions of large, heavy nuclei (e.g. Au or Pb), a new state of nuclear matter consisting of liberated quarks and gluons is formed at a temperature of trillion Kelvins. This state of matter, commonly referred to as Quark Gluon Plasma (QGP), was discovered and confirmed at the Relativistic Heavy Ion Collider (BNL) and the Large Hadron Collider (CERN). The QGP was found to exhibit collective behavior and flow as a nearly “perfect” fluid. The elementary collision systems such as proton-proton (pp) or proton-nucleus (pA), which were thought to be too small and dilute to form a QGP, were treated as references in understanding the perfect fluidity in large heavy ion systems. Surprisingly, evidence for collective effects and QGP formation has been revealed in those smallest collisions in the recent years, when looking at rare events releasing large number of particles. In this talk, I will go over key findings related to the possible QGP formation in pp and pA systems and discuss their implications, as well as future opportunities at RHIC and LHC.
        Speaker: Zhenyu Chen (Shandong University)
        Slides
      • 10:50 AM
        alpha团簇结构在相对论重离子碰撞中的效应 20m
        报告介绍相对论重离子碰撞中集体流、HBT关联、手征电磁场的计算,讨论在不同碰撞系统下这些可观测量与碰撞系统初始几何构型的关联,建议通过系统扫描实验鉴别alpha团簇结构存在的可能性。
        Speaker: Dr 松 张 (Fudan University)
        Slides
      • 11:10 AM
        深度学习核变形因子 20m
        深度学习是目前最好的模式识别算法。通过可微分的误差向后传递,深度学习可以在任意两组存在连续几何变换的数据集之间建立映射。我们使用34层的残差神经网络,在变形核与变形核的高能碰撞模拟末态,与核的变形因子之间建立映射。深度学习成功从碰撞末态粒子的个数与各向异性流之间的关系中,定量提取碰撞核的变形因子绝对值。我们设计了回归注意力掩码算法,来可视化深度神经网络在做出决策时的关注区域。神经网络的注意力区域显示,全重叠碰撞对大的核变形因子敏感,而半重叠碰撞,对所有的核变形因子敏感。此研究应该可以推广到低能核碰撞,从大量低能核核碰撞末态粒子的动量分布(同位旋分布),提取碰撞核的核子密度分布,中子皮等信息。
        Speaker: Dr LongGang Pang (CCNU)
        Slides
      • 11:30 AM
        Weak $p_{T}$ dependence of inclusive jet $R_{AA}$ and extraction of jet energy loss distributions 20m
        The observed suppression of inclusive jets in heavy-ion collisions at LHC has a very weak $p_{T}$ dependence over a large range of $p_{T}$ = 50-1000 GeV and is almost independent of the colliding energy, though the initial energy density of the formed QGP has increased significantly from $\sqrt{s}$ = 2.76 to 5.02 TeV. This interesting phenomenon is fully investigated in the linear Boltzmann transport(LBT) model for jet propagation combined event-by-event 3+1D hydro backgrounds. We found that the $p_{T}$ dependence of jet $R_{AA}$ is determined by the initial spectrum in $pp$ collisions and jet quenching in which medium response has a significant contribution. Furthermore, the energy loss distribution is extracted directly from experimental data within a Beyesian method, which provides a model-independent approach to understand jet quenching in detail. The extracted jet energy loss distributions have a scaling behavior and indicate that jet quenching is caused on the average by only a few out-of-cone scatterings.
        Speaker: Yayun He (Central China Normal University)
        Slides
      • 11:50 AM
        System and event activity dependences of inclusive jet production with ALICE 20m
        Jets are produced by a high momentum transfer of initial partons at high energies. Comparing jet production in pp and nucleus-nucleus collisions will allow us to study the jet-quenching effect caused by the hot and dense QCD medium produced in nucleus-nucleus collisions when energetic partons traverse the medium. In particular, systematic studies of jet production in different multiplicity environments will provide in-depth understanding of the medium properties and its evolution from small to large systems. In small systems and high multiplicity events, the particle bulk behaves as if a hot QCD medium was created, but such behavior is not observed with hard probes. Therefore, a detailed study of the jet production in different collision systems and different event activity with various jet resolution parameters will help us to investigate further the existence of medium effects on jets in small systems with high multiplicity. In this presentation, the jet cross section measurements in different collision systems using the data taken by ALICE during the LHC RUN2 will be presented. The jet nuclear modification factor, which characterizes the jet-quenching effect, will be pre sented using different jet resolution parameters. In order to study the jet collimation properties, the jet cross section ratio for different jet resolution parameters will be also measured and compared to different theoretical models.
        Speaker: 永珍 侯 (华中师范大学)
        Slides
    • 10:30 AM 12:10 PM
      S4:探测器和电子学及应用技术 科学会堂301

      科学会堂301

      华中师范大学

      武汉
      Conveners: 志权 陈 (武汉大学) , 怀林 李 (国家电投集团科学技术研究院有限公司)
      • 10:30 AM
        基于SiPM双端读出的CsI(Tl)探测器研究 20m
        摘要:目前,中能区(200keV-50MeV)伽马射线天文的发展远落后于低(<200keV)、高(>50MeV)能区,发展新型高灵敏度的伽马射线探测器对于开展中能区的伽马射线研究具有非常重要的科学意义。国际上公认最好的中能区伽马射线探测器为康普顿望远镜,量能器作为其组成部分应具有高能量分辨率和高位置灵敏度,为此,设计了一种基于硅光电倍增管(SiPM)双端读出的CsI(Tl)探测器,作为康普顿望远镜量能器的基本探测单元。使用137Cs作为伽马射线放射源,硅光电倍增管(SiPM)作为光电转换器件,对Teflon、Tyvek和ESR三种包装材料下的5×5×80mm3晶体和ESR包装材料下的5×5×60 mm3、5×5×80 mm3和5×5×100mm3三种尺寸晶体探测器进行了比较测试。实验结果表明,通过双端读出信号幅值的方式,CsI(Tl)探测器可以确定入射伽马射线的总能量以及在晶体中的相互作用位置。其中,在662keV伽马射线照射下,Teflon、Tyvek和ESR三种包装材料的探测器能量分辨率分别为5.6%、5.4%和5.2%(FWHM),差别并不明显,而光衰减长度和位置分辨率却表现出明显的负相关性,光衰减长度分别为:99.8mm、142.4mm和210.3mm,对应的位置分辨率分别为:3.3mm、4.3mm和5.2mm(FWHM)。此外,对于ESR包装下的三种不同晶体尺寸探测器,其性能并没有表现出显著的差异,能量分辨率、位置分辨率和光衰减长度分别在5.0-5.3%、5.0-5.2mm(FWHM)和190-220mm范围内。 关键词:CsI(Tl)探测器;硅光电倍增管;能量分辨率;位置分辨率;光衰减长度
        Speaker: Mr 相满 刘 (河南工业大学 电气工程学院/中国科学院近代物理研究所)
        Slides
      • 10:50 AM
        超声分子束和低温等离子体相互作用研究 20m
        在磁约束聚变等离子体的研究领域中,超声分子束(supersonic molecular beam,简称SMB)是一种有效的诊断等离子体的手段,超声分子束和等离子体相互作用对于聚变等离子体的加料和诊断都具有一定的研究价值。本实验基于核工业西南物理研究院的直线型等离子体装置LEAD(Linear Experimental Advanced Device),研究了超声分子束和等离子体的相互作用过程。LEAD装置中的等离子体是在弱磁场约束(大约400Gs)条件下的低温等离子体(温度在eV量级),同托卡马克装置中边缘等离子体参数相近,因此本研究可以用于模拟SMB和托卡马克装置的边缘等离子体的相互作用。 实验中SMB和等离子体的源气体均采用氩气,喷气时间为3ms。SMB经过一个特殊设计的skimmer去除边缘横向扩散速度较大的分子,并自由飞行一段距离后进入LEAD装置中和等离子体发生相互作用,用高速相机采集相互作用产生的辐射光,来研究相互作用过程。拍摄速度分别设置为3200fps和50000fps,以记录较大空间区域的广域反应过程和局部反应过程。通过分析广域空间的亮度演化过程,发现当SMB密度较大时,SMB可以直接阻断等离子体柱。当SMB密度减小后,SMB可以使等离子体柱发生一定程度的弯曲形变,但是不能阻断等离子体柱。当SMB密度较小时,SMB不能改变等离子体柱的形状。 通过研究局部反应过程,发现可通过图像中亮斑头部的位置移动信息来计算SMB在等离子体中的传播速度。结果发现当SMB刚进入等离子体中时,其传播速度最大,之后其传播速度逐渐减小至0。速度峰值在15bar-45bar范围内约为80m/s到380m/s,且随着背压的增大而逐渐增大,当背压超过45bar后,速度峰值保持基本不变或略有下降。射频功率决定了等离子体的密度,功率越大,等离子体密度越大,对应的速度峰值越小。对于SMB阻断等离子体柱的情况,阻断时间的范围在0.7ms到2.6ms。阻断时间随着背压的增大而增大,随着射频功率的增大而减小。这些研究结果在一定程度上验证了之前模拟计算的结果,同时对于深入研究SMB和磁约束聚变中的等离子体相互作用具有重要的意义。 ---------- 基金资助和作者简介: 基金资助:本次实验得到了国家自然科学基金(11575121, 11275133) 和国家磁约束聚变项目(2014GB125004)的支持。 作者简介:刘东,男,四川大学物理学院博士研究生,主要研究超声分子束的性质及其和其它物质,如电子、等离子体和激光等的相互作用。
        Speaker: Mr 东 刘 (四川大学物理学院)
        Slides
      • 11:10 AM
        基于硅光电倍增管的高时间分辨塑闪探测器读出方案的优化设计 20m
        摘要:Bρ-TOF-ΔE方法是中、高能区弹核碎裂型放射性次级束流分离器上常用的粒子鉴别方法,其TOF探测器时间分辨的好坏,直接决定着碎片质量数的鉴别。塑料闪烁体具有较快的上升时间,高的光学透过率、易加工制造、价格便宜等优点,特别适合于TOF探测器的研制。在次级束物理实验中,一般要求TOF探测器在具有较好的时间分辨的同时,还应具有较大的灵敏面积及较薄的物质层厚度。然而,塑料闪烁体面积越大、厚度越薄,闪烁光的收集效率越低,越不利于好的时间分辨的获得。因此,本文选用尺寸为100×100×0.5 mm3的EJ212塑料闪烁体片,采用多个硅光电倍增管(SiPM)读出,通过改变SiPM数量及连接方式等,对此大面积塑闪片的时间性能进行了测试。结果表明,采用双端读出、单端12支SiPM串联的连接方式可得到的最佳的时间分辨~120ps。这一研究对中、高能区弹核碎裂型放射性次级束流线上TOF探测器的研制具有重要的指导意义。 关键词:TOF探测器;硅光电倍增管;时间分辨;大面积薄塑闪;
        Speaker: Ms 冰倩 周 (中科院近代物理研究所)
        Slides
      • 11:30 AM
        活化法测量natMo(p,x)99mTc的反应截面 20m
        **摘要:** 99mTc是目前医学诊断应用最广泛的放射性同位素。传统99mTc的生产方式主要通过在反应堆中辐照高浓缩235U裂变生成的99Mo衰变得到,这种生产方式存在长途运输损失,且成本高,具有核扩散风险。加速器生产医用同位素具有更大优势,如系统更安全,可调,运行灵活,方便,生产效率高等。基于中科院近物所ADS强流超导直线加速器,利用质子束轰击天然钼靶,开展了99mTc医用同位素实验测量研究,实验通过活化法测量100Mo(p,2n)99mTc的反应截面,并结合Gent4模拟进行了分析对比,实验结果与数据库及计算结果一致。 关键词:天然钼靶,直线加速器,99mTc,活化法
        Speaker: Ms 慧 孙 (中国科学院近代物理研究所)
        Slides
    • 12:10 PM 1:30 PM
      午餐 1h 20m 桂苑宾馆

      桂苑宾馆

      华中师范大学

      武汉
    • 1:30 PM 3:30 PM
      大会邀请报告
      Conveners: Prof. Feng-Shou ZHANG (College of Nuclear Science and Technology,Beijing Normal University) , 瑚珊 徐
      • 1:30 PM
        超重核实验研究 30m
        Speaker: 再国 甘 (impcas)
        Slides
      • 2:00 PM
        强激光等离子体下核反应与核激发研究 30m
        Speaker: Prof. 长波 符 (复旦大学)
        Slides
      • 2:30 PM
        Beyond mean-field description of Gamow-Teller resonances and beta-decay half-lives 30m
        Speaker: Yifei Niu (L)
        Slides
      • 3:00 PM
        中国高能核物理国际合作进展 30m
        Speaker: XIAOMING ZHANG (Institute of Particle Physics, Central China Normal University)
        Slides
    • 3:30 PM 4:00 PM
      茶歇 30m 科学会堂

      科学会堂

      华中师范大学

      武汉
    • 4:00 PM 5:00 PM
      新一届理事会任职和宣布下届会议
    • 9:00 AM 12:00 PM
      参观华中师范大学实验室及超算中心
      • 9:00 AM
        硅像素实验室 1h 9号楼7楼

        9号楼7楼

        华中师范大学

        武汉
        Speaker: Mr 向明 孙 (华中师范大学)
      • 10:00 AM
        硅像素探测器安装实验室 1h 9号楼负一楼

        9号楼负一楼

        华中师范大学

        武汉
        Speaker: Prof. Yaping Wang (Central China Normal University)
      • 11:00 AM
        核科学计算中心 1h 9号楼负二楼西头

        9号楼负二楼西头

        Speaker: Prof. Heng-Tong Ding (Central China Normal University)