缪缪论坛——缪子物理与缪子技术创新学术论坛

Jul 12, 2026, 8:00 AM → Jul 13, 2026, 12:00 PM Asia/Shanghai

W202 (July 12) & M212 (July 13), School of Physics (Peking University)

Cheng-en Liu (Peking University) , Leyun Gao (Peking University)

诚挚邀请您参加 “缪缪论坛——缪子物理与缪子技术创新学术论坛”。论坛将在北京大学物理学院举办，由北京大学物理学高层次人才培养中心和北京大学高能物理研究中心提供经费支持。

• 报到时间：7 月 12 日
• 会议时间：7 月 12 日–7 月 13 日

（排名不分先后）

本论坛为研究生自主筹办的学生学术论坛，面向国内外对缪子科技感兴趣的在读本科生、硕士研究生、博士研究生、在站博士后等，聚焦缪子物理前沿与缪子应用技术，以学生汇报、专家点评、自由研讨为主要形式，欢迎以上人员投稿展示课题进展，也欢迎各位老师帮忙转发通知给相关专业师生。

论坛研讨方向包括但不限于：

• 缪子反常磁矩
• 标准模型测量和新物理探寻
• μSR 技术和应用
• 缪子加速器和缪子束流
• 缪子探测器
• 缪子对撞机
• 缪子无损成像和应用

诚挚欢迎对缪子科技感兴趣的在读本科生、硕士研究生、博士研究生、在站博士后等报名参会，同时热忱邀请领域专家老师莅临指导。

本次论坛不收取任何费用，参会人员食宿自理，请尽早预订周边酒店。

会议日程可能随报告人数变动而调整。

Sunday, July 12

注册签到与自由交流

开幕式

1 开幕介绍

Speakers: Cheng-en Liu (Peking University) , Leyun Gao (Peking University)

缪缪论坛问答

2 评委、嘉宾代表及主办单位致辞

青年报告: 缪子束流平台与新型加速技术

Convener: Jinning Li (Peking University)

3 HIAF 上的缪子束流和相关应用

缪子在基础物理前沿探索和重大应用研究中具有不可替代的重要价值。强流重离子加速器装置HIAF可提供国际领先的高强度脉冲离子束，依托其高分辨率次级束流线，有望产生GeV量级、能量连续可调、高通量的单能缪子束，在束流强度、能量覆盖范围和应用潜力等方面具有显著优势。2025年10月，HIAF首次成功实现束流全线贯通，标志着我国已具备开展高能缪子源研究的重要平台条件。本报告将介绍HIAF装置建设与束流调试的最新进展，以及高能缪子束线的设计方案、关键技术和实验规划。未来，依托HIAF高品质缪子束，将开展暗物质搜寻、缪子反常磁矩精密测量、缪子—核子散射等前沿物理研究，并探索单能缪子束在重核材料高分辨成像与无损探测等领域的创新应用，为基础科学研究和重大应用技术发展提供新的机遇与平台支撑。

Speaker: He Zhao (Institute of Modern Physics)

4 CiADS-MuST缪子源进展

缪子作为微观世界的探针，是诸多新物理发现及物理应用的强力工具。为满足世界日渐增多的高精度高强度缪子源的需要，基于我国加速器驱动嬗变研究装置（CiADS）3MW的超导直线加速器，CiADS缪子源（MuST）有望成为最高强度的连续型缪子源。MuST缪子源由两个靶站，四条缪子束线组成，分两期进行建设。目前，缪子靶站，缪子束线，缪子谱仪已完成概念设计，能满足极化率大于95%，本底率小于1%，缪子流强到达1e8/s的实验终端需求。

Speaker: 锦程 李 (中国科学院近代物理研究所)

5 Muon Beamline Optimization Based on AI

Muons have broad applications in muon spin rotation (μSR), muon tomography, precision measurements, and muon colliders, driving increasing demand for higher beam intensity and quality. This report presents our research progress on optimizing muon beamline design using AI methods. Two intelligent optimization approaches were employed: Genetic Algorithms (GA) and the Center-Evolving Algorithm (CE). The GA method was validated on the μE4 beamline, achieving over 20% improvement in surface muon intensity compared to the original optics design, with a 10% gain in online beam tuning. It also supported the feasibility design of the MELODY surface and decay muon beamlines. To address GA's weak convergence precision in small beam spot optimization, the CE method was developed — incorporating parallel simulation, parabolic-fitting gradient descent, and random jump strategies — successfully achieving a small beam spot of 7.8×10⁵ μ/s within ∅20 mm at 20 kW for the MELODY surface muon beamline.

Speaker: 聪 陈 (中国散裂中子源和中科院高能所)

6 飞焦束团驱动的多级缪子尾场加速理论

高能缪子束在缪子对撞机和高能物理领域具有重要的应用前景。然而，由于缪子的质量远大于电子质量，低能缪子在等离子体尾波场中的初始速度相对较低，容易在加速过程中失相，使其难以被捕获和持续加速。为了解决这一问题，本报告研究了低能缪子在非线性啁啾电子束驱动的变速飞行焦点等离子体尾场中的注入与多级加速理论。具有非线性能量啁啾的电子束在穿过色散光学元件后，其不同切片因色差效应在不同纵向位置依次聚焦，从而在等离子体中激发出相速度从亚光速到近光速跃变的动态尾场结构。基于随动坐标系下的多级哈密顿量守恒理论，本文构建了缪子在双阶段尾场中的相空间动力学模型。通过推导级间切换时的相空间重叠与映射关系，解析给出了实现连续多级加速缪子的二维边界，理论模型得到了三维PIC模拟的验证。最后，报告探讨了驱动束与等离子体参数对捕获阈值与能量增益的定标律。综上所述，报告提出了一种束流驱动等离子体尾场缪子加速新方法，为未来实现紧凑型高能缪子加速器提供了新的理论途径。

Speaker: 立琦 韩 (北京大学)

7 交流讨论

茶歇与自由交流

青年报告: 精密缪子实验与稀有过程搜索

Convener: Dr Alim Ruzi (Xinjiang University)

8 [Remote from Japan] Muon g−2 Experiments: From Fermilab to J-PARC and HIAF

The muon anomalous magnetic moment, aμ=(gμ−2)/2, is a precision observable that provides a stringent test of the Standard Model and a sensitive probe of new physics. The Fermilab Muon g−2 experiment has completed the world’s most precise measurement of aμ, reaching a total uncertainty of 127 ppb. This talk will review the experimental method, including the storage of polarized muons, the measurement of the anomalous spin-precession frequency, magnetic-field calibration, and the principal analysis and systematic-control strategies.

The final Fermilab result will be discussed in the context of comparisons with Standard-Model predictions. The talk will also introduce the ongoing J-PARC muon g−2/EDM experiment, which uses an ultra-cold low-emittance muon beam, three-dimensional spiral injection, a compact storage magnet, and positron tracking to realize an independent measurement with distinct systematic uncertainties.

Finally, the prospects for a future muon g−2 experiment at HIAF will be presented. The proposed CANTON-μ program aims to exploit intense GeV-scale pulsed muon beams for a next-generation measurement at sub-0.1-ppm precision. Together, these programs illustrate the continuing role of precision muon measurements in testing the Standard Model and searching for physics beyond it.

Speakers: Zejia Lu (Shanghai Jiao Tong University) , Ce Zhang (University of Liverpool (UK))

9 Physics-Informed Neural Networks for 3D Magnetic Field Reconstruction in Precision Muon Experiments

High-precision three-dimensional magnetic field mapping is crucial for precision muon experiments, particularly in beam transport, injection, and storage regions where direct sensor access is often restricted. We present a Physics-Informed Neural Network (PINN) framework that incorporates Maxwell’s equations (∇·B = 0 and ∇×B = 0) directly into the training loss. The method features a dual-constraint strategy enforcing physics consistency at both collocation points and measurement locations, along with a three-stage optimization (AdamW, LBFGS, and Residual-based Adaptive Refinement).

Biot-Savart simulations demonstrate reconstruction accuracy reaching ~10^{-4}, representing a tenfold improvement over prior PINN methods, with strong robustness against sparse data and noise. Laboratory experiments using a custom coil assembly under ambient conditions achieve sub-percent relative accuracy (down to 10^{-3} level).

In collaboration with J-PARC researchers, a small-scale application to a 3D-injection simulation dataset achieved approximately 1% prediction error. These results highlight the potential of PINNs as a powerful tool for high-precision magnetic field reconstruction in muon g−2/EDM and related experiments.

Speaker: 展绪 郝 (Shanghai Jiao Tong University)

Physics-Informed Neural Networks for 3D Magnetic Field Reconstruction in Precision Muon Experiments.pdf

10 [Remote] 正反缪子素转化实验（MACE）研究进展

正反缪子素转化实验（MACE）是我国自主提出的下一代缪子物理实验，旨在寻找破坏带电轻子味的正反缪子素转化过程，是研究超越标准模型的新物理的灵敏探针。该实验将依托我国加速器驱动嬗变研究装置（CiADS）规划的高强度表面缪子束流，预期将转化过程的实验灵敏度较当前国际最好水平提高两个数量级以上。目前已完成概念设计，相关成果发表于《Nuclear Science and Techniques》封面文章。研究系统开展了缪子素产生靶、米歇尔电子磁谱仪、正电子输运系统及正电子探测系统的设计与模拟优化，并评估了新物理探测潜力。实验预期单事例灵敏度可达1.3×10⁻¹³，90%置信度转化概率上限为3.8×10⁻¹³，比国际最佳结果8.3×10⁻¹¹提高两个数量级以上。此外，团队还规划了一期实验，将利用电磁量能器、塑闪定时探测器和塑闪光纤径迹探测器预先研究其他缪子稀有衰变过程，在验证探测器性能的同时进一步拓展物理研究范围。MACE实验是我国缪子物理前沿的重要布局，可与粤港澳大湾区多个缪子源建设计划协同，有望在轻子味破坏研究中取得国际领先成果，为探索超越标准模型的新物理提供关键实验证据。本报告将介绍MACE实验及其近期研究进展。

Speaker: Shihan Zhao (Sun Yat-Sen University)

11 钍缪探测与核钟进展研究

核同质异能素 $^{229\mathrm{m}}\mathrm{Th}$ 具有约 $8\,\mathrm{eV}$ 的激发能，是核钟的主要候选，将彻底革新精密测量和基础物理研究。近期在 $^{229\mathrm{m}}\mathrm{Th}$ 辐射衰变观测以及在 $^{229}\mathrm{Th}$ 掺杂晶体中直接核激光激发方面取得的突破性进展，激发了一系列面向固态核钟实现的基础性工作。然而，主要从 $^{233}\mathrm{U}$ 衰变中提取的 $^{229}\mathrm{Th}$ 在全球范围内的稀缺性，以及制备高掺杂 $^{229}\mathrm{Th}$ 晶体靶材所面临的材料科学挑战，构成了核钟发展的严重瓶颈。在此，我们通过展示将 $^{232}\mathrm{Th}$ 掺杂晶体原位转化为 $^{229}\mathrm{Th}$ 掺杂变体，提出了应对这些挑战的解决方案。利用天然丰度高的 $^{232}\mathrm{Th}$ 同位素作为前驱体，能够实现用于固态核钟的 $\mathrm{SrF}_2$ 晶体的安全且可规模化的生产。通过电子束轫致辐射诱导的光核反应，我们在 $^{232}\mathrm{Th}:\mathrm{SrF}_2$ 和 $^{232}\mathrm{Th}:\mathrm{CaF}_2$ 晶体中实验验证了这种光核转化技术，同时保持了它们的真空紫外透光性。该过程通过 $(\gamma, 3n)$、$(\gamma, 2np)$ 和 $(\gamma, 2pn)$ 反应生成 $^{229\mathrm{m,g}}\mathrm{Th}$ 以及母体同位素 $^{229}\mathrm{Ac}$ 和 $^{229}\mathrm{Ra}$。离线 $\gamma$ 射线能谱显示 $^{229}\mathrm{Th}$ 浓度达到约 $10^{9}\,\mathrm{cm}^{-3}$ 量级。利用高通量宽带伽马射线源，$^{229}\mathrm{Th}$ 浓度可能在数小时内达到 $10^{15}\,\mathrm{cm}^{-3}$，与直接激光激发实验中使用的晶体相当。此外，虽然对辐照后的 $\mathrm{SrF}_2$ 和 $\mathrm{CaF}_2$ 晶体的真空紫外光谱显示存在 $^{229\mathrm{m}}\mathrm{Th}$ 直接光子衰变的证据，但 $\mathrm{SrF}_2$ 晶体的真空紫外透光性基本上无需任何退火即可恢复，这对于 $^{229}\mathrm{Th}$ 的长期辐照生产具有重要意义。该方法克服了同位素可用性和放射性操作方面的关键限制，为探索各种固态基质晶体以及核钟的可规模化生产铺平了道路。

Speakers: Meizhi Wang (Peking University) , Di Wu (Peking University) , Haoyang Lan (Peking University) , Xueqing Yan (Peking University)

12 Production of lepton-flavor-violating scalars through resonant positive-muon annihilation on atomic electrons

We study a light scalar $\phi$ with lepton-flavor-violating $e$–$\mu$ couplings, directly probed via resonant $\mu^+ e^- \to \phi$ production at high-intensity muon beams. In fixed-target experiments, target electrons are bound and have relativistic momenta, which smear and broaden the resonance. We develop a fully relativistic bound-state framework that accounts for these atomic effects and accurately predicts production rates. Our projections show that HIAF can probe couplings down to $\mathcal{O}(10^{-5})$ with short runs, demonstrating strong sensitivity complementary to traditional LFV searches.

Speaker: Mr Jinhong Shen (Peking University)

CLFV_mue_phi_MuMu.pdf

13 Design and simulation of exotic muon decay searches with PID using HIAF muon beam

Muon physics and detector design have always been a key focus of particle physics research. We design a simulation experiment on muon rare decay based on the HIAF beam, including particle identification and decay simulation, which provides relatively good sensitivity and offers a concept for detector design.

Speaker: 凌志 董 (北京大学)

14 交流讨论

午餐与自由交流

青年报告: 缪子相关新物理、宇宙线与空间环境

Convener: Jinhong Shen (Peking University)

15 Probing Cosmic Ray Composition and Muonphilic Dark Matter via Muon Tomography

Cosmic-ray muons provide a unique probe of both particle interactions and potential signals of new physics. We present a novel cosmic-ray scattering experiment using a resistive plate chamber (RPC) muon tomography system, where the scattering angle between incident and outgoing tracks is exploited as a key observable. This approach enables simultaneous studies of secondary cosmic-ray composition and searches for dark matter interactions. During a 63-day data-taking campaign, $1.18\times10^6$ cosmic-ray scattering events were recorded and analyzed. By performing combined template fits to the measured angular distributions, the abundances of different cosmic-ray components are extracted, with the electron fraction determined at the $\sim2\%$ level. The same dataset is further used to search for elastic muon–dark matter scattering in muonphilic dark matter scenarios. No significant excess above the expected background is observed, and constraints on the scattering cross section are derived. For a $1\,\mathrm{GeV}$ slow dark matter particle, the $95\%$ confidence level upper limit reaches $1.61\times10^{-17}\,\mathrm{cm}^2$. These results demonstrate the potential of cosmic-ray scattering measurements as a novel tool for both precision cosmic-ray studies and searches for light muon-coupled dark matter.

Speaker: 昊 方 (北京大学)

16 Search for light Dark Sectors with GeV Muon Beams

Sub-GeV light dark matter often requires new light mediators, such as a dark Z' boson in the Lµ − Lτ gauge theory. We study the search potential for such a Z' boson via the process µe −> µeX,with X decaying invisibly, in a muon on-target experiment using a high-intensity 1–10 GeV muon beam from facilities such as HIAF-HIRIBL. Events are identified by the scattered muon and electron from the target using the silicon strip detectors in a single-station telescope system. Backgrounds are suppressed through a trained BDT classifier, and activity in downstream subdetectors remains low. We find that this approach can probe a Z' in the 10 MeV mass range with improved sensitivity. Nearly three orders of magnitude improvement is achievable using a full multi-telescope station system using a 160 GeV muon beam at CERN, such as in the MUonE experiment.

Speaker: Zijian Wang (北京大学)

17 Search for Higgs decay to two muons

A search for the Higgs boson decay to two muons is performed using LHC proton–proton collision data. The analysis targets the $H \to \mu^+ \mu^-$ channel, which is sensitive to the Yukawa coupling of the Higgs boson to muons. Events are split into exclusive categories based on jet multiplicity and kinematic properties to maximize signal sensitivity. A multivariate classifier is used to separate signal from the dominant Drell–Yan background. Signal is extracted with a simultaneous fit across all categories to observables chosen for each category.

Speaker: Qianying GUO (Peking University)

18 在缪子对撞机上寻找规范玻色子之间的量子纠缠

A TeV-scale muon collider is a promising successor to the LHC, offering unique opportunities to study rare processes and fundamental quantum phenomena. We investigate the prospects for observing quantum entanglement and Bell inequality violation in $H \to ZZ \to 4\ell$ events. The spin density matrix of the $ZZ$ system can be reconstructed from the decay kinematics of the charged leptons, enabling the evaluation of Bell operators and the characterization of quantum correlations between the two $Z$ bosons. Using Monte Carlo simulations, we show that the generalized CGLMP inequality can be maximally violated and that Bell inequality tests can be established with high statistical significance. These results demonstrate the potential of future muon colliders to probe quantum entanglement in the high-energy regime.

Speaker: Dr Alim Ruzi (Xinjiang University)

19 Progress on Atmospheric Muon Flux Simulation Using CORSIKA

CORSIKA (COsmic Ray SImulations for KAscade) is a widely used Monte Carlo program for simulating extensive air showers induced by cosmic rays. In this work, it is used to simulate the atmospheric muon flux using the Papini primary proton spectrum. Muons are weighted according to their parent primary energy, and the flux is normalized using an equivalent exposure time derived from the total simulation weight. For near-vertical muons (0°–5°), the simulated differential energy spectrum agrees well with experimental measurements over 0.1–10⁵ GeV, validating the simulation framework. Ongoing studies of large zenith angles (70°–80°) reveal a systematic discrepancy with data, with possible origins including Earth's curvature effects and the simulation geometry.

Speaker: 卓 陈 (Peking University)

20 交流讨论

茶歇与自由交流

青年报告: 缪子成像算法、系统误差与探测器技术

Convener: 仲行 徐 (清华大学)

21 宇宙射线投影偏移粒子流成像技术

宇宙射线μ子成像是一种重要的无损检测技术，但在实际测试时间内实现毫米级分辨率仍面临挑战。为此，我们提出了投影偏移μ子透射成像框架（PμMA），该框架通过融合透射与散射信息，实现了高分辨率成像。与传统依赖散射角定位的方法不同，PμMA通过连接上下游探测器记录的μ子击中位置，构建透射径迹，并将材料引起的μ子散射投影为成像平面内的可观测位置偏移。该方法仅需两个探测器即可实现毫米级分辨率成像，显著提升了可用μ子事例率，并大幅降低了系统成本。我们还发展了多探测器配置方案，通过限制最大散射角，进一步增强了对不同质量厚度材料的鉴别能力。
在模拟研究中，针对30 mm厚铅块，宇宙射线条件下获得的表征分辨能力的刃边宽度最小为1.196 mm；在4 GeV单能平行μ子束条件下，最优刃边宽度可达0.048 mm。在实验验证中，系统在2天内成功实现了对2 mm铜片结构的成像，性能优于同等条件下的传统方法。

Speaker: Zibo Qin (Peking University)

22 Nuisance-Aware Muon Tomography

宇宙线缪子层析成像本质上是一个被nuisance参数主导的逆问题。缪子断层扫描仪成像两种材料对比度——来自多次库仑散射的辐射长度和来自电离能损的电子密度——但每种对比度都与一个探测器无法直接观测的缪子级nuisance参数纠缠：散射尺度携带未知的逐缪子动量，能损携带单侧的straggling尾部。传统方法将每条径迹压缩为一个派生标量并代入标称动量，未能正确处理这些nuisance参数。

我们提出 Nuisance-Aware Muon Tomography（NAMT），依据仪器条件针对性地处理每种nuisance。散射通道（NAMT-S）运行在无磁铁径迹探测器上：精确的track-elimination投影消去直线径迹自由度，未测动量通过逆Gamma共轭先验被解析积分为鲁棒的Student-t 似然函数。能损通道（NAMT-E）运行在磁谱仪上：利用磁弯曲测量逐缪子对数动量损失，将其作为电子密度对比度的Bethe–Bloch线积分进行反演，采用匹配Huber空白校正消除straggling偏置。所有nuisance参数均在无物体的空白扫描上标定——将CT平场校正从均值推广到全部nuisance参数——重建过程中无需对被成像物体做任何调参。

在包含高Z（铅、铀）和低Z（空气空洞、聚乙烯）目标的8场景Geant4基准测试中，NAMT-S仅凭无磁铁四平面径迹探测器即可达到八场景平均ROC-AUC 1.00，在探测器位置分辨率劣化至3 mm时仍保持0.94；NAMT-E在所有场景均达到1.00，提供稳定的互补通道。代码开源于 https://github.com/zhizhengzhao/NAMT。

Speaker: Mr Zhizheng Zhao (Peking University)

23 次级粒子对基于PoCA算法的宇宙射线成像的影响研究

This work reinterprets “noise” in cosmic-ray imaging, showing that PoCA points outside the traditional volume of interest carry valuable physical information. Analysis of four-layer RPC data and Monte Carlo simulations with energy-weighted coordinates confirms that these points arise from muon interactions with materials above the detector, particularly the roof, producing secondary particles. Two main findings emerge: first, in the four-layer system, the first-layer records may come from secondary particles, while the lower three layers reflect true cosmic-ray trajectories; second, the roof strongly influences PoCA point distributions, with roof thickness correlating quantitatively with reconstructed points, measurable via $z$-coordinate analysis. Differences in roofing materials suggest this method could evolve into a novel tomography technique.

Speaker: Mr 荣峰 张 (北京大学)

24 具有动量测量功能的缪子成像系统的搭建与测试

宇宙线缪子成像技术利用缪子与成像目标的相互作用，通过探测缪子与的径迹变化或计数率变化对客体目标进行成像。传统的缪子成像技术一般不考虑宇宙线缪子本身能量的差异带来的散射性质的影响，在这一前提下需累计一定量的缪子计数才能达到理想的成像效果。模拟表明，如果知道缪子的动量信息，并通过动量数值对缪子的散射角进行加权，就能够通过相对较少的缪子计数实现物质材料鉴别等功能。本文采用飞行时间测量法，基于 MRPC 搭建了一套成像区域面积 $0.25~\mathrm{m^2}$ 的缪子散射成像系统。系统由两个时间分辨 MRPC，4 个位置分辨 MRPC 构成。时间分辨 MRPC 为 4 室 32 气隙结构，宇宙线测试时间分辨率在 $30~\mathrm{ps}$ 左右。位置分辨 MRPC 为 1 室 5 气隙结构，宇宙线测试位置分辨率约为 $0.8~\mathrm{mm}$。时间测量系统电子学采用基于 DRS4 的波形采样板，径迹测量系统电子学采用基于 ADC 的波形采样系统。系统初步对铅砖、铁样件进行了成像扫描，并得出测量结果。

Speaker: Mr 大铭 刘 (清华大学)

25 基于缪子透射成像的开封繁塔内部结构观测分析

通过使用缪子透射成像方法，为北宋遗存砖石古建筑——开封繁塔，做“CT”成像。塔身隐性内部病害难以通过传统物探手段检测。本次采用宇宙射线缪子透射成像无损探测技术，开展繁塔塔身全域成像观测试验，利用高能宇宙缪子穿透衰减特征反演塔体内部介质密度分布，重构繁塔内部三维结构图像。完成古建筑深部无接触无损扫描，弥补传统文物检测技术短板；本次观测数据可为繁塔文物安全评估、保护性修缮提供参考。

Speaker: 辰 李 (华北电力大学)

26 宇宙线缪子成像技术在水利工程安全中的应用实践

宇宙线缪子成像是一种无源、无损、非接触式的深部结构探测技术，可用于获取大型工程体内部密度变化信息。本研究中，团队形成了适用于复杂水利工程现场的缪子成像观测系统，并在地下输水隧道、水库工程等典型场景开展安装、调试和连续观测，获取了工程体内部结构相关的缪子观测数据，形成了二维/三维成像结果和现场应用证明。实践表明，该技术能够在不破坏工程结构、不引入人工辐射源的条件下，对深部隐蔽空间和低密度异常进行识别，为水利工程安全监测提供新的技术手段和应用范例。

Speaker: 建鸣 张 (华北电力大学)

27 交流讨论

晚餐与自由交流

Monday, July 13

青年报告: 缪子成像应用：核材料、地质工程与月球探测

Convener: 大铭 刘 (清华大学)

28 面向核材料无损检测的缪子散射成像：多种聚类方法在复杂场景下的系统性评估

不开箱、无额外辐射识别集装箱、核废料桶内高 Z 重金属与特种核材料，是海关安检、核材料管控及核废料处置的核心需求，缪子散射成像作为最优被动式检测手段被广泛研究。工程上普遍采用 PoCA 快速成像算法，却始终存在目标分割、材料分档两大关键瓶颈，且现有相关算法缺乏统一标准下的横向性能对比。我们基于 Geant4 搭建四层多丝正比室缪子成像仿真系统，设计 7 组覆盖各类复杂工况的差异化验证场景，在统一数据接口下对比 5 类主流聚类算法与自研图像分割方法。整套识别流程集成背景扣除、地形学突起度寻峰、散射 - 能损双模态自适应分档，有效改善物体密排粘连、弱目标被强目标散射晕覆盖、空气背景引发虚警等缺陷。测试结果表明自研图像分割方案综合性能最优，可稳定区分铅、钨等高 Z 非核重金属与铀、钚类核材料，但该技术固有局限导致铀与钚无法区分。本研究建立标准化算法测试基准，厘清各类聚类算法的适用场景与失效条件，创新目标分割判据；后续将完善量化评价体系、标定有效原子序数、融合多成像模态，推动该技术落地海关货检工程应用。

Speaker: Chenghao Zheng (火箭军工程大学)

29 Muon tomography based on Micromegas

Muon tomography has witnessed remarkable progress driven by technical innovations over recent decades. Most muon scattering occurs at small angles well fitted by Gaussian functions, yet large-angle scattering contributes disproportionately to material characteristic indices, whose precise modeling is essential for high-fidelity tomographic reconstruction. This work investigates large-angle muon scattering and verifies a novel characterization method via experimental measurements. Following Molière’s scattering theory, we hypothesize the angular distribution obeys a zero-centred Breit-Wigner profile. Cosmic muon tracks are reconstructed via the Point of Closest Approach (PoCA) algorithm to extract scattering angles. Imaging performance is tested with multiple 2 cm cubic tungsten assemblies of distinct layouts. Experimental outcomes confirm the Breit-Wigner model’s outstanding robustness against angular cutoff constraints, highlighting its promising applicability for muon scattering imaging and multi-target material differentiation. Relevant findings have been published in Physica Scripta and will be elaborated in this talk.

Speaker: Ms 宇晗 范 (华北电力大学)

30 基于钻孔条件约束下深地矿脉勘探的双螺旋缪子探测器模拟研究

本研究面向钻孔直径受限条件下深部地下矿脉勘探需求，提出了一种紧凑型圆柱形三层塑料闪烁体宇宙线缪子探测器结构。该探测器由内层与外层反向螺旋塑料闪烁体条以及中间层轴向垂直排列的矩形塑料闪烁体条组成。反向螺旋结构用于获取缪子入射方位信息，中间垂直层用于增强轴向定位约束，从而在井下有限空间内兼顾探测效率、方向重建能力和位置分辨能力。基于Geant4 蒙特卡洛模拟平台，并结合EcoMug宇宙线缪子源模型，本文对探测器几何参数与探测性能之间进行了研究，重点研究了闪烁体条宽度、厚度以及螺旋角对探测效率、方位角分辨率、天顶角分辨率和位置分辨率的影响。模拟结果表明，当闪烁体宽度为10 mm、厚度为10 mm、螺旋角为21°时，探测器综合性能达到较优水平，模拟测得对应方位角分辨率为48.16 mrad，天顶角分辨率为14.41 mrad，位置分辨率为3.17 mm。进一步构建高密度矿体模型和低密度空腔模型开展成像验证，结果显示该探测器能够有效响应不同密度异常区域，重建结果可较好反映目标体空间位置及密度差异特征。研究表明，所提出的双螺旋圆柱形三层塑料闪烁体探测器在深部地下钻孔缪子探测与矿脉成像中具有较好的适用性，可为井下受限空间条件下的缪子成像探测系统设计提供参考。
关键词：缪子成像，Geant4，蒙特卡洛模拟，缪子径迹探测器，探测器建模与模拟

Speaker: 立志 王 (南华大学核科学技术学院)

应用于深地矿脉勘探的宇宙射线缪子探测器研究.pptx

31 面向地质体结构勘查的宇宙线缪子成像探测系统设计与研究进展

宇宙线缪子成像技术利用天然宇宙射线缪子在不同密度介质中的衰减差异，实现对物体或地质体内部结构的非破坏性探测。该技术具有穿透能力强、无需人工放射源、环境友好等特点，在矿产资源勘查、地下空间探测和复杂地质结构识别等领域具有潜在应用价值。针对坑探条件，本研究设计了基于塑料闪烁体与光电转换器件耦合的大面积缪子成像系统。该系统有效探测面积为 500 mm × 500 mm，可实现毫米级位置分辨，为缪子通量测量和径迹重建提供实验基础。针对钻探条件下探测空间受限的问题，进一步开展了小直径钻井型缪子探测系统设计研究，采用塑料闪烁体光纤构建紧凑型径迹探测结构，使其适用于钻孔环境，并具备多井联合探测的应用潜力，并可引入地震、重力等方法获得的地层密度先验模型，可提高复杂地质条件下密度异常体识别和空间定位的可靠性。

Speakers: 思远 罗 (南华大学) , Mr 立志 王 (南华大学)

32 缪子透射系统在大坝检测场景中的应用

Large concrete dams require non-invasive methods capable of probing internal density structures over metre-to-decametre scales, especially when detailed geometric priors or internal drawings are incomplete. Here we report a field-deployable plastic-scintillator muon transmission imaging framework for quantitative structural imaging of the reservoir dam in Yichang, Hubei, China. The framework combines detector-response modelling, Geant4-based dam-scale simulation, scattering-migration analysis, low-count transmission reconstruction and limited-prior three-dimensional localization. Applying the calibrated reconstruction pipeline to field data, we resolve and localize gallery-like internal low-density structures in the dam and estimate their spatial extent under limited geometric priors. We further assess the potential of the same framework for suspicious defect-candidate localization using controlled simulations. Our results demonstrate that muon transmission imaging can provide a cautious and quantitatively interpretable probe of internal structures in large concrete infrastructure.

Speaker: 子扬 陈 (Tsinghua University)

33 The muon Moonshot: Moon subsurface tomography with upward-going muons

Muon tomography has been widely used on Earth to probe internal structures using secondary cosmic-ray muons. We investigate its application to the Moon by studying muons produced in the lunar regolith. Using Monte Carlo simulations, we evaluate the energy spectrum, angular distribution, and flux of muons escaping the lunar surface under different regolith conditions. The results show that the angular muon flux is sensitive to near-surface composition, indicating its potential as a non-invasive tool for lunar subsurface exploration. Possible detector configurations and applications in future lunar missions, including the Chang’e program, are briefly discussed.

Speaker: Mr Zimo Hu (Peking University)

34 交流讨论

茶歇与自由交流

评奖与总结

35 颁奖

Speakers: Cheng-en Liu (Peking University) , Leyun Gao (Peking University)

36 合影

Speaker: Yinxuan Qu (Peking University)

37 总结讨论与论坛反馈

38 未来展望

期待您承办下一届缪缪论坛！