分类: 核科学技术 >> 粒子加速器 提交时间: 2023-11-07
摘要: EPICS控制软件广泛应用于粒子加速器等大型科学实验装置。根据装置规模的不同,其EPICS PV的数量从几万到上百万不等,快速查询EPICS PV的相关信息,可提升加速器的运维效率。为此,设计和开发了EPICS PV信息平台,该平台支持在统一的用户界面中查询 PV列表、实时状态、历史数据、操作日志以及IOC状态、IOC网络信息,并将这些信息关联在一起,实现综合展示。平台的用户界面采用Web技术,服务端基于Node.js运行环境开发以及结合EPICS社区已有的软件模块,网络信息采集等周期执行的程序采用Python语言开发。目前,EPICS PV信息平台已应用于CSNS加速器,并在实际运维中发挥了重要作用。
分类: 物理学 >> 核物理学 提交时间: 2023-07-12
摘要: The 232Th(n,f) cross-section is very important in basic nuclear physics and applications based on the Th/U fuel cycle. Using the time-of-flight method and a multi-cell fast fission ionization chamber, a novel measurement of the 232Th(n,f) cross-section relative to 235U in the 1200 MeV range was performed at the China Spallation Neutron Source Back-n white neutron source (Back-n). The fission event-neutron energy spectra of 232Th and 235U fission cells were measured in the single-bunch mode. Corrected 232Th/235U fission cross-section ratios were obtained, and the measurement uncertainties were 2.53.7% for energies in the 220 MeV range and 3.66.2% for energies in the 20200 MeV range. The 232Th(n,f) cross-section was obtained by introducing the standard cross-section of 235U(n,f). The results were compared with those of previous theoretical calculations, measurements, and evaluations. The measured 232Th fission cross-section agreed with the main evaluation results in terms of the experimental uncertainty, and 232Th fission resonances were observed in the 13 MeV range. The present results provide 232Th(n,f) cross-section data for the evaluation and design of Th/U cycle nuclear systems.
分类: 物理学 >> 核物理学 提交时间: 2023-12-15
摘要: Nondestructive and noninvasive neutron assays are essential applications of neutron techniques. Neutron resonance transmission analysis (NRTA) is a powerful nondestructive method for investigating the elemental composition of an object. The back-streaming neutron line (Back-n) is a newly built time-of-flight facility at the China Spallation Neutron Source (CSNS) that provides neutrons in the eV to 300 MeV range. A feasibility study of the NRTA method for nuclide identification was conducted at the CSNS Back-n via two test experiments. The results demonstrate that it is feasible to identify different elements and isotopes in samples using the NRTA method at Back-n. This study reveals its potential future applications.
分类: 物理学 >> 核物理学 提交时间: 2024-03-10
摘要: Theutilization of a proton beam fromthe China Spallation Neutron Source (CSNS) for producingmedical radioisotopes is appealingowing toits high current intensity and high energy. The medical isotope production based on the proton beam at the CSNS is significantfor the development of futureradiopharmaceuticals, particularly for the α-emitting radiopharmaceuticals.The production yield and activity of typical medical isotopes wereestimated using theFLUKA simulation. The results indicate that the 300-MeV proton beam with a power of 100 kW at CSNS-II ishighly suitable for proof-of-principle studies of most medical radioisotopes. In particular, this proton beam offers tremendous advantages for the large-scale production of alpha radioisotopes, such as 225Ac, whose theoretical production yield can reach approximately57 Ci/week. Based on theseresults, we provideperspectives on the use ofCSNS proton beams to produce radioisotopes for medical applications.
分类: 物理学 >> 核物理学 提交时间: 2024-05-10
摘要: 中国散裂中子源(CSNS)可提供0.3 eV至300 MeV的白光中子束流,总束流强度可达107n/s/cm2,为中子俘获反应截面的测量提供了一个优秀的实验平台。CSNS在正常的运行模式下会由加速器产生两个间隔410 ns的质子束团先后打靶,因此产生的中子束流也由间隔为410 ns的两个束团混合而成。为避免两个束团的效应相互干扰,影响中子俘获截面的能量精度,需要对实验数据进行解析和重构,还原单个束团的效应。现有的解析方法可以得到非常精细的解谱结果,但相对复杂,具有一定使用门槛。本工作提出了一种简化的双束团解谱方法,在保证中子能量精度的情况下适用于中子能量低于1.2 MeV的数据,为同类型的实验工作提供一种新的数据处理思路。
分类: 核科学技术 >> 辐射物理与技术 提交时间: 2024-06-10
摘要: This study investigates the effects of displacement damage on the dark signal of a pinned photodiode CMOS image sensor (CIS) following irradiation with back-streaming white neutrons from white neutron sources at the China Spallation Neutron Source (CSNS) and Xi’an Pulsed Reactor (XAPR). The mean dark signal, dark signal non-uniformity (DSNU), dark signal distribution, and hot pixels of the CIS were compared between the CSNS back-n and XAPR neutron irradiations. The non-ionizing energy loss and energy distribution of primary knock on atoms in silicon, induced by neutrons, were calculated using the open-source package Geant4. An analysis combining experimental and simulation results showed a noticeable proportionality between the increase in the mean dark signal and the displacement damage dose (DDD). Additionally, neutron energies influence DSNU, dark signal distribution, and hot pixels. High neutron energies at the same DDD level may lead to pronounced dark signal non-uniformity and elevated hot pixel values.
分类: 物理学 >> 核物理学 提交时间: 2024-02-20
摘要: 在中国散裂中子源反角白光终端,测量了中子能量为33.9MeV 12C(n,d)x的角微分反应截面。利用轻带电粒子探测器阵列(LPDA)E-E 望远镜系统, 测量了在实验室坐标系下从24.5到155.5 12C(n,d)x 的角微分反应截面。实验结果能够很好的符合以前的实验结果。由于缺少实验数据,这项工作为相关数据库的评价及数据库研制提供了重要参考。