RIBLL终端光纤矩阵探测单元时间分辨测量

本文描述了兰州放射性束流线(RIBLL)终端大面积闪烁光纤矩阵探测装置的结构。用两种方法测量了该光纤矩阵单元的时间分辨,得到的最佳时间分辨为520ps(FWHM)。光纤矩阵探测装置的角分辨为?φ≈0.39°,?θ≈0.79°。同时,实验研究了探测器所用光导的传输效率和对时间分辨的影响。     

塑闪墙在束性能测试

在HIRFL通用散射室的终端调试时完成了0°附近Pilot U塑闪墙的性能测量,给出了位置分辨为Δx=3cm,时间分辨为600ps,并能分辨出Z≤6的几种主要粒子,测得100×5×1cm~3的Pilot U有效光速为16.37cm/ns,有效衰减长度为92.4cm,并解决了同一条塑闪在0°附近的粒子多击问题。     

用大角度伴随粒子法测量聚变中子产额及其校对实验

描述了用大角度（178.2°）伴随α粒子方法测量绝对D-T 聚变中子产额及其校对实验。为此,设计和加工了一套三叉管校对靶室,α粒子探测器分别置于与D∧ 束成90°、135°和178.2°的方向上,测量和比较了三个方向的α粒子谱和绝对中子产额。分析了实验误差来源,并对实验结果进行了讨论。     

大面积闪烁光纤阵列探测器的在束测试

利用70AMeV²⁶Mg初级束流及其产生的次级束流,在兰州重离子加速器放射性次级束流线（RIBLL）终端测试了大面积闪烁光纤阵列探测器(LASFA)探测单元的时间分辨和位置分辨能力。利用70AMeV²⁶Mg初级束流测试得到的时间分辨约为128ps,对应的位置分辨约为10mm;利用次级束流测试得到的时间分辨约为158ps,对应的位置分辨约为13mm,具有很好的时间分辨和空间角分辨能力。结合RIBLL的ΔESi探测器,给出了ΔE_Si-TOF二维谱,并将测试结果与RIBLL的粒子鉴别系统进行详细比较。结果表明,大面积闪烁光纤阵列作为轻带电粒子的飞行时间终止探测器,性能优于RIBLL上采用的时间拾取探测器,可更清楚地鉴别次级束流。     

关联α粒子探测器设计和性能研究

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。本文依托中国原子能科学研究院核数据重点实验室移动中子发生器,结合具有快时间响应的ZnO：Ga与最新的位置灵敏光电倍增管(PSPMT)H13700,设计可用于API的关联α粒子探测器系统。通过SCDC-TCOG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1 mm,并通过狭缝法和栅条法进行了验证。通过测量²⁵²Cf裂变碎片和瞬发伽马符合测量获得系统时间分辨好于1 ns,达到了应用需求。     

双栅位置灵敏雪崩室

本文描述了一个灵敏面积为250mm×200mm,采用双栅结构的两维位置灵敏雪崩室。在流动的360 Pa的异丁烯气体中,使用~(252)Cf裂变源对探测器的性能进行了检验,得到Δx=Δy=4mm的位置分辨和Δt=290ps的时间分辨。     

基于能量-速度关联技术的裂变产物质量分布测量方法研究

采用能量E-速度v关联技术测量裂变产物碎片的动能和飞行速度能精确测定裂变产物核的质量。本工作主要研究能量-速度关联技术的可行性并解决相关关键技术。实验测量系统由飞行时间测量单元、能量探测器和真空靶室系统组成。实验中用1对微通道板探测器测量粒子飞行时间来确定粒子速度,金硅面垒探测器测量粒子能量。对于~(241) Am放射源5.48 MeVα粒子,飞行时间测量系统时间分辨(FWHM)为186ps,金硅面垒探测器能量分辨(FWHM)为44keV。实验完成了~(252) Cf自发裂变源产物质量分布试测量。初步实验结果显示,裂变产物质量分布在110amu(amu为原子质量单位)的位置时,其质量分辨为1.6amu。     

位置灵敏塑料探测器阵列

本文描述了一个有效探测面积为100×70cm~2的位置灵敏塑料闪烁探测器阵列,它由两条100×5×1cm和6条100×10×1cm的Pilot U型塑料闪烁体组成。用~(252)Cfα放射源测得10cm宽的闪烁体的时间分辨、位置分辨和能量分辨分别为740ps,5.7cm和60％;5cm宽的闪烁体分别为610ps,4.7cm和40％。     

一台锯齿形阳极位置灵敏电离室

本文介绍了一台锯齿形极位置灵敏电离室，它是在普通电离室的基础上把阳极改变为锯齿形结构，从而实现对带电业子位置的测定，用＾２４１Ａｍ源的α粒子对探测器的性能进行了测试，得到的能量分辨为２％，位置分辨好于２ｍｍ。     

一种多极平行板雪崩探测器

描述了一种为RIBLL研制的在线束流监测用双维位置灵敏多极平行板雪崩探测器(Multi-platePPAC)。它主要由中心阳极、两个位置灵敏栅极和两个阴极平面组成。灵敏面积为100mm×100mm。使用异丁烷工作气体,气压稳定在650Pa,阳极在+400V,阴极在-350V时,对三组分α源测得探测器的位置分辨约0.58mm(FWHM),位置非线性±50μm,探测效率好于99.2%。由于该探测器明显的高增益,它适合探测较高能量的较轻粒子。     

Au-Si面垒型带电粒子望远镜的研制

介绍了厚度为350μm、有效面积为530mm~2的△E和厚度为700μm、有效面积为1380mm~2E探测器所组成的全耗尽Au-Si面垒型带电粒子望远镜的制备工艺、测试结果(Thc-c'源8.78MeV的能量分辨率△E探测器为0.8%、E探测器分辨为1.2%)和该探测器的主要用途.     

GEANT4 simulation of photo-peak efficiency of small high purity germanium detectors for nuclear power plant applications

GEANT4 – based Monte Carlo simulations have been carried out for the determination of photo-peak efficiency of heavily shielded small high purity germanium detector (HPGe) used for monitoring radiation levels in nuclear power plants. The GEANT4 simulated values of HPGe detector efficiency for point as well as for disk sources, for two different values of collimator diameter, have been found in good agreement with the corresponding published results obtained by using the MCNP code. The work has been extended to study the effect of radial displacement of a source relative to a detector on photo-peak efficiency for both point and disk source, and at various values of γ-ray energies. Also the effect of disk source radius on photo-peak efficiency has been studied. Besides the results of different available physics models in GEANT4 have also been compared. The computed values of efficiency for point as well as for disk sources using the Penelope and Livermore physics models have been found correspondingly consistent for various values of γ-ray energies while some differences (e.g., Penelope model yields 6.3% higher values of photo-peak efficiency for Eγ = 1.332 MeV, 10 mm collimator diameter) have been observed in the corresponding valued obtained by using the Standard physics model.     

Overview of the SLD

The SLD is a second generation detector for the SLAC Linear Collider (SLC). It is optimized for Z° physics and exploration of new physics in the Z° energy region. The SLD will have a CCD vertex detector, high resolution drift chambers for momentum measurement, a ?erenkov Ring Imaging Detector for particle identification, and calorimetry based on lead/liquid argon followed by an iron/gas system. The detector covers the full solid angle.     

应用于PandaX-Ⅲ实验探测器测试平台的Bulk Micromegas性能研究

探测无中微子双贝塔衰变的PandaX-Ⅲ实验需要一个能同时对多个Micromegas探测器的增益、能量分辨、坏道分布、位置分辨等性能参数进行测试的平台,为此中国原子能科学研究院建立了PandaX-Ⅲ实验探测器测试平台。本文采用由光蚀刻技术制作的Bulk Micromegas对该测试平台进行研究：利用⁵⁵Fe放射源在Ar+10%CO₂的流气情况下,使用基于AGET读出芯片制作的通用读出电子学进行数据采集;运用C++与ROOT软件库编写相应的后端数据分析软件,并对数据进行了分析。测试结果表明,PandaX-Ⅲ实验探测器测试平台各系统工作状态良好,应用于测试平台的Bulk Micromegas探测器具有良好的信噪比,X射线成像效果清晰,对5.9 keV X射线的能量分辨率为19.7%。     

Multi-elemental characterization of organic liquid samples by use of a 13 MeV Li beam

Evaporated amniotic fluid (AF) targets have been bombarded with a 13 MeV ⁶Li³⁺ beam. Forward angle data have served to identify the ¹H(⁶Li,¹H)⁶Li reaction as an alternative for hydrogen characterization of such organic samples. Detected ⁶Li ions elastically scattered from C, N, O, Na and Cl can also be used to determine the concentrations of these elements in AF. The analyzed AF samples have been diluted with distilled water. The effect of sample dilution on the improvement of spectrum energy resolution has been observed, confirming previous reports. The hydrogen concentration determined in the studied AF targets is shown to vary linearly with sample dilution. Two detector arrangements have been used to find out which detection scheme is the most convenient. The combination of a counter telescope and a single detector, set up at the same polar angle on the opposite side of the beam, seems to be the best choice to have a reliable particle identification and an adequate energy resolution simultaneously.     

高分辨X射线成像器件——微间隙室(MGC)的研究

详细讨论了微间隙室的基本结构、特性及其主要研究内容;并在此基础上,探讨了微间隙室采用金刚石薄膜作为阳极电极微条和阴极电极微条之间的极间绝缘材料的可能性和有效性。为在第三代同步光源上实现具有良好时间和空间分辨的成像实验或衍射实验,提供了一种潜在的辐射成像探测器。     

Applications of Detectors in Low Energy Nuclear Physics

This review paper discusses new applications of detectors in low energy nuclear physics and emphasizes semiconductor particle detectors where new developments have had an outstanding influence on the nuclear physics which can be done. The paper includes an account of: new limits of detector resolution; a new method for measurement of gamma ray lifetimes; gamma-gamma angular correlation studies with multiple scintillation detectors; kinematic energy shift correction with radial position sensitive detectors; an improved particle identification system with multiple detectors; and the application of germanium to measurements of long-range charged particles. The paper also discusses present state-of-the-art limitations and possibilities in areas of particular importance to nuclear physics.     

中国先进研究堆中子织构谱仪的分辨率和极图窗研究

为计算中国先进研究堆（CARR）中子织构谱仪的分辨率和极图窗,基于倒空间衍射几何的误差分析推导了谱仪分辨率和极图窗的计算公式,并将其应用于CARR中子织构谱仪。结果表明,极图窗近似为狭窄的长方形,其沿β方向的分辨率较高,沿α方向的分辨率随衍射角变化较大。对于特定的衍射角,³He管点探测器的α分辨率为固定值,而二维位置灵敏探测器的α分辨率可根据样品和织构分布的测量需要沿纵向进行分份调整。     

双维位置灵敏探测器性能测试

对用于放射性次级束测量的大面积双维位置灵敏探测器（PSD）的性能进行了测试。通过选择实验中电子线路的脉冲成形时间,并改进数据处理方法,即主放大器的成形时间常数要大于6μs,而位置路的时间常数约为0．5－1μs,且在位置公式中使用能量信号作为公母,测试得到了较好的位置分辨和能量分辨及线性。结果表明,这一类型的PSD探测器可以用于低能放射性束流的测量。     

Depth resolution of TOF-ERDA using a He beam

Depth resolution of time-of-flight ERDA using a ⁴He beam (He TOF-ERDA) has been studied. The measurement system consists of a time detector of the ion transmission type and a silicon surface-barrier detector. Depth resolution was measured using samples of carbon layers on silicon wafers and ⁴He beams with energies between 3.5 and 10.1 MeV. The depth resolution of 6.0 ± 1.6 nm (FWHM) was obtained with a 3.5 MeV ⁴He incident beam. The measured depth resolution agreed with that evaluated by a calculation. Comparison with other methods such as heavy ion (HI) TOF-ERDA, resonant elastic scattering and nuclear reaction analysis (NRA) was performed. Depth resolution obtained by He TOF-ERDA is superior to that by NRA or resonant elastic scattering, and comparable to that by HI TOF-ERDA.