Conveners
Parallel Session 3: Neutron detection & Methodical aspects/Physics of ultracold neutrons: (1)
- Maxim Zakharov (Joint Institute for Nuclear Research)
Parallel Session 3: Neutron detection & Methodical aspects/Physics of ultracold neutrons: (2)
- Tiancheng Yi ()
Parallel Session 3: Neutron detection & Methodical aspects/Physics of ultracold neutrons: (3)
- Changqing Feng (中国科学技术大学)
Parallel Session 3: Neutron detection & Methodical aspects/Physics of ultracold neutrons: (4)
- Alexander Nezvanov (JINR)
Recent progress of the phycical design for the the Ultra-cold Neutron Source at CSNS
A concept is presented for an ultracold neutron (UCN) source with a superfluid helium converter placed in the thermal column of the WWR-K research reactor (Almaty, Kazakhstan). Similar source designs are employed in the existing TRIUMF project (Vancouver) [1] and the proposed project at the WWR-M reactor (Gatchina) [2]. The main distinguishing features of our concept are more efficient systems...
The development of intense low-energy neutron sources requires extensive calculations to refine the design to meet practical needs. With the appearance of liquid helium-based ultracold neutron sources (UCN), from which all UCN can be released through a small outlet, it became possible to use a new type of mirror neutron guides. They consist of three main parts: a short expanding part, a long...
This study presents numerical and analytical investigations aimed at optimizing the measurement of ultracold neutron (UCN) loss factors on various materials using the gravitational [1] spectroscopy method. The optimization of experimental setup geometry was performed through numerical simulations, allowing for the determination of optimal parameters to enhance measurement accuracy. Within the...
Fast neutron radiography offers distinct advantages over conventional X-ray radiography, demonstrating significant developmental potential and broad application prospects in strategic fields including national defense, aviation, aerospace, and nuclear energy. As a critical performance indicator for imaging systems, spatial resolution has been extensively studied through theoretical simulations...
The report is devoted to the problem of interaction of slow neutrons with matter moving with acceleration. The possibility of transformation of the neutron dispersion law due to the general effect of acceleration is considered. The Acceleration effect consists of that the result of the interaction of a particle with any object moving with acceleration should be a change in its frequency ω and...
Nanodispersed media, such as nanodiamond powders, are efficient diffuse reflectors of low-energy neutrons [1]. This is due to the intense coherent elastic scattering of such neutrons on individual nanoparticles of a few nanometers in size. Such reflectors can be used for quasi-specular reflection of cold neutrons [2] and in the design of very cold neutron sources for their directed extraction...
For the first time, the author proposed the concept of a new direction in the field of cold (cryogenic) neutron moderators for research neutron sources of low, medium and high power and intensity, which is based on the use of a universal cryogenic neutron moderator based on hydrocarbons. It is shown that the successful development of fundamentally new methods, installations, devices and...
A new high-brilliance ultracold neutron (UCN) source is planned to be created for the FLNP JINR pulsed reactor. It is planned to carry out a series of investigations using VCNs, which are essential for the design of the main elements of this UCN source. For this purpose, a test VCN channel at the third channel of the IBR-2M reactor will be built. This will allow us to obtain a VCN beam with a...
The investigation of neutron-induced fission independent yields of actinides is critically important for both the efficient utilization of nuclear energy and nuclear physics research. The fission spectrometer based on the velocity-kinetic energy method consists of a Time Of Flight (TOF）detector and a Frisch-Grid Ionization Chamber (FGIC), achieving mass yield distribution with a mass...
There are several instruments on the flight bases of the IREN facility that are used to carry out measurements on the transmission, capture and scattering of neutrons on samples.
The analysis of experimental data, the assessment of the possibility of conducting, and the planning of experiments with IREN beams require knowledge of the facility parameters: the absolute fluxes of resonance and...
The energy distributions and absolute yields of the long-range alpha particles and the tritons in thermal neutron induced ternary fission of 235U were measured using a twin-gridded ionization chamber. The experimental result shows that the long-range alpha particles and the tritons can be separated obviously in the cathode amplitude vs anode amplitude two-dimensional spectrum, and the absolute...
Conventional photon and neutron bimodal imaging systems suffer from inherent limitations such as different imaging beam geometry, leading to challenges in direct fusion of transmission image and system complexity. While the single-source-single-detector configuration based on a compact electron linear accelerator proposed by Tsinghua University addresses imaging beam geometry issue, it remains...
The Multi-purpose Time Projection Chamber (MTPC) prototype has been successfully developed and commissioned at the CSNS Back-n white neutron beamline. As a novel detection system, its primary design objective focuses on precise measurement of light charged particle emissions in nuclear reactions, while maintaining versatile capabilities for multiple applications including fission cross-section...
Neutron capture reactions play a crucial role in nuclear physics research, as their cross-section measurements provide critical data for nuclear structure studies and nuclear databases, while also enabling the examination of symmetries and conservation laws in nuclear reactions. To meet the requirement for neutron capture cross-section measurements at the back-streaming neutron facility...
To establish a comprehensive and reliable nuclear database for neutron-induced processes, the development of accelerator-driven system (ADS) technology is essential. Despite many efforts have been made, accurate measurements of light charged ions (LCIs), including protons, tritium, and α particles, at zero degrees in the beam direction remain challenges. Conventional detectors often fail to...
The specific geometry of small angle neutron scattering spectrometer YuMO, a central
hole along the neutron beam direction through the two scattering detectors reaching to direct
beam detector (DBD) located at 35 meters from moderator [1-3]
DBD importance return to determine the transmittance of the sample as a function of
wavelength, due to peculiarities of normalization when the ratio...
The work presents application of the particle detection techniques developed in the field of High-Energy Physics (HEPh) to neutron detection. This area has been growing rapidly over the past decade due to ongoing developments at CERN, JINR and other research centers.
Mictro-Pattern Gaseous Detectors (MPGD), such as GEMs, or Gas Electron Multiplier, Micro-Megas, micro-RWELL, micro-GROOVE,...
The damage effect caused by high energy particles, especially Single Event Upset (SEU), is one of the major factor of failure in SRAM-based FPGA components, for applications in harsh radiation environments, such as space-borne payloads and ground-based large scale particle experiments. With the advancement of the integrated circuit industry, in nowadays the feature size of high-performance...
Abstract:
With the advancement of science and technology, the field of Inertial Confinement Fusion (ICF) has entered a new era where fusion yields are sufficiently high to enable nuclear measurements to provide multidimensional information encompassing spatial, temporal, and spectral dimensions. Nevertheless, neutron yield remains one of the most critical parameters of concern in the...
The current polyethylene-moderated 3He neutron detector suffers from low detection efficiency and a dependence on the neutron energy and emission angle, which hinders the accurate measurement of critical data for astrophysical modeling, such as (α, n), (γ, n) cross sections, and β-delayed neutron emission probabilities. To address this, a novel detector design was proposed, using a large...
With the development of ultra-short and ultra-intense laser technology, laser driven plasma electron acceleration is becoming increasingly mature. Compared with traditional RF acceleration, this acceleration method has significant characteristics - an acceleration gradient three orders of magnitude higher. It is precisely because of its ultra-high acceleration gradient that the accelerated...
The dispersed moderating agent for cryogenic moderators of the IBR-2M reactor is produced by the formation of droplets and subsequent freezing in liquid nitrogen. The heat exchange between the droplet and liquid nitrogen leads to intensive local boiling of the liquid nitrogen, resulting in vapor cushioning and heat exchange. This phenomenon is known as the Leidenfrost inverse effect.
The...
The Department of Spectrometers Complex (DSC) of IBR-2 plays an important role in maintaining the efficiency and development of the experimental facilities at the IBR-2 reactor. One of the directions of DSC is the development and creation of wide-aperture neutron detectors based on the 6LiF/ZnS(Ag) scintillator. As part of the modernization of the scientific installations of the IBR-2 reactor,...
This study analyzes the differences in the operation and heat distribution of single-beam and multi-beam Accelerator-Driven Systems (ADS) through burn-up simulation calculations. Compared to conventional single-beam configurations, the multi-beam ADS achieves a flat neutron flux and heat distribution, effectively suppressing radial power peaking. The distributed spallation target design in...
Numerical modeling of the interaction of fast and thermal neutrons with semiconductor microcrystals (InSb, InAs, GaAs) was conducted using the GEANT4 software environment. The study aimed to determine the rates of nuclear reactions (elastic and inelastic scattering, radiative capture) and analyze the influence of secondary fission products on the radiation resistance of semiconductor...
