紧凑型磁质子反冲谱仪磁分析系统的能量刻度

介绍了一种用于多种特定环境下脉冲氘氚聚变中子能谱测量的紧凑型磁质子反冲谱仪的磁分析系统。通过三维粒子输运和蒙特卡罗模拟对磁分析系统性能进行了分析,使用CR-39径迹探测器和多个能量α单能粒子对系统进行了能量刻度。结果表明,磁分析系统具有良好的能量离散与聚焦性能,对给定能量范围的反冲质子,能够以1.5%~2.1%的能量分辨率实现（0.5~1.4）×10^－4的探测效率。     

磁质子反冲谱仪磁分析器的设计与谱仪性能研究

设计一种用于紧凑型磁质子反冲(magnetic proton recoil,MPR)谱仪的小型单聚焦磁分析器,用钕铁硼二级永磁铁作分析磁铁,焦平面探测器为CR39。用实际磁铁的磁场分布数据和带电粒子输运程序分析磁分析器的性能,并用Pu-239α源实验标定。结合粒子输运程序的结算和蒙特卡罗模拟,研究了MPR谱仪的整体性能。结果表明:磁分析器能对3.5-8.5MeV范围内的质子和α粒子进行动量分析,有良好的动量色散和径向聚焦能力,符合紧凑型MPR谱仪的设计要求;对14MeV的DT聚变中子,谱仪有4%的能量分辨率和10-8的探测效率。     

磁约束聚变“点火”装置中聚变中子测量

概述了大、中型托卡马克在D-D和D-T运行条件下聚变中子能谱和强度的测量的最新方法;推介了几种最新的聚变中子探测器和能谱仪及活化分析方法;评估了各种聚变中子探测器和能谱仪的优势,适用的范围和技术方面的局限性。对即将建成的HL-2A(中环流器二号A型)托卡马克的聚变中子的泄漏能谱和辐射强度的时、空分辨测量以及研究聚变中子在通过中子倍增剂过程中的能谱变化,在探测器方面提供了几种可供选择的技术方案。     

反冲质子探测系统中子灵敏度的Monte Carlo算法

在强流脉冲中子测量工作中,常利用PIN探测器测量中子与聚乙烯中的H核发生弹性散射产生的反冲质子.本文利用Monte Carlo技术进行快速计算的反冲质子探测系统中子灵敏度表达式,给出了算法和计算流程.     

硅半导体二重符合反冲质子望远镜

文章叙述半导体二重符合反冲质子望远镜的调试和在14MeV中子源上与伴随粒子法的比对测量。     

静态真空度对PIN-反冲质子探测系统测量的影响

在用于脉冲中子辐射场测量的PIN-反冲质子探测系统中,静态真空的获得和保持是顺利开展测试、获取可信结果的重要保证。论文从真空度对测量产生影响的两个主要方面着手进行了研究:(1)计算了真空度对中子测量计数损失的影响;(2)分析了适于PIN探测器使用的真空条件。从两方面综合考虑,提出实际应用时将系统静态真空指标确定为百帕左右是合理和可行的。     

反冲质子谱的计算模拟及氢深度分布的研究

本文介绍了一种弹性反冲探测分析冲质子谱模拟的计算方法。用这种方法对４０ｋｅＶ质子注入硅中和非晶硅薄膜中氢浓度的深度分布进行了研究，并取得了良好的结果。     

中子通量测量的质子反冲望远镜

研制了用于测量D-T中子通量的质子反冲闪烁望远镜,望远镜由二个对带电粒子响应的半导体探测器(△E)和一个CsI(TI)闪烁探测器(E)组成.利用脉冲形状甄别技术抑制CsI闪烁探测器的γ射线本底,△E探测器的高偏压对提高信噪比是重要的.二个△E探测器和一个E探测器实现了三重符合.在三重符合条件下,通过有、无辐射体的测量得...     

D-T中子源的反冲质子望远镜模拟研究

为了设计用于监测D-T中子产额的反冲质子望远镜系统,采用MCNP程序模拟了14MeV中子在不同厚度的聚乙烯膜上产生的反冲质子的产额、能谱及角分布,通过对反冲质子的产额、能谱和角分布数据的分析,给出了用于D-T中子产额监测的反冲质子望远镜系统的聚乙烯膜最佳厚度和探测器放置位置。建立了D-T中子源模型,模拟设计了反冲质子望远镜系统,并给出了系统的探测效率。     

中子核反应中反冲核的平均射程

用活化法测量了快中子核反应中反冲核在靶中的平均射程,发现不同的核反应（ｎ,２ｎ）,（ｎ,ｐ）,（ｎ,ａ）和（ｎ,ｎｐ）中的反冲核的平均射程存在系统性规律,导出了经验公式。此外,把理论公式计算的结果同实验结果进行了比较,并给出了修正的理论计算公式。     

HD-2010质子旋进磁力仪的研制与应用

简单阐述了HD-2010质子旋进磁力仪测量地磁场的原理、介绍了新一代质子旋进磁力仪的电路和程序设计,通过中国计量科学研究院的计量测试及野外实际应用证明HD-2010质子旋进磁力仪的技术指标达到了国内、外同类仪器水平,验证了仪器设计的可靠性和先进性。     

Neutron response functions and detection efficiency of a spherical proton recoil proportional counter

<正>The neutron response function and detection efficiency of a spherical proton recoil proportional counter (SP) play key roles in precise measurement of neutron spectra of the interior materials.In this paper,the response functions and detection efficiency of three SPs developed at CAEP are simulated by Geant4.The simulated spectra are compared with pulse-height spectra measured at 0.165,0.575,1.4,and 14.1 MeV of incident neutrons.And the calculated detector efficiencies agree within 5%with the data obtained by neutron activation.     

170MeV硫离子入射引起的反冲氩离子产额

利用１７０ＭｅＶ的Ｓ＾９＋与Ａｒ原子气体靶发生碰撞反应,采用高能离子引起的多重电离的飞行时间技术,测量了反冲击离子相对产额,并与多体经典轨道蒙特卡罗理论的计算结果进行了对比分析,发现理论低估了较高电荷态反冲离子的产额。     

N~+和Bi~+离子注入InP反冲原子P和In深度分布偏离的研究

本文给出了用背散射和沟道技术所分析的N~+和Bi~+注入InP中In和P原子位移的面密度分布。发现移位原子In和P面密度分布峰的深度随注入剂量的增大而加深。在相同的剂量下磷原子分布峰与表面的距离比In原子峰的大。从移位原子面密度分布峰的移动和分布的展宽与注入剂量的关系出发,研究了离子注入过程中所存在的反冲效应。并讨论了移位原子的反冲机理。     

Energy and angular distribution of recoil proton of fast neutron in scintillation fiber： a simulation study

Due to their low cost,big reaction cross-section with neutrons,flexibility,and convenience for long distance data transfer,plastic scintillation fibers (PSF) have been increasingly used as detectors or sensors for high-energy neutron radiography.In this paper,Geant4 Monte Carlo simulation tool was used to obtain some chalacteristics of energy and angular distributions of recoil protons in plastic scintillation fibers irradiated by fast neutrons.The plastic fiber with BCF-20 as the core and an acrylic outer cladding was used in the simulation.The results show that there is a big range of energy and angular distribution of recoil protons in energies varying inversely with the recoil angle.     

On the useful range of application of molecular dynamics simulations in the recoil interaction approximation

The validity of the binary collision (BC) approximation and of the so-called recoil interaction approximation (RIA) in ion–solid interactions at low energies is investigated by comparison with molecular dynamics (MD) simulations. The systems studied are channeling through a (1 1 0) oriented layer of Si, implantation into a (1 0 0)-Si target, and reflection from (1 0 0)-Si. It is found that the BC approximation does not introduce significant errors in the case of channeling simulations even at very low energies. Under non-channeling conditions an upper limit to the break-down energy of the BC approximation in Si is given by 30M₁^0.55 eV, taking 5% deviation in the projected range as the criterion.     

Investigation of the confinement of high energy non-neutral proton beam in a bent magnetic mirror

By using the particle-in-cell (PIC) simulation method, we studied how the proton beam is confined in a bent magnetic mirror. It is found that the loss rate of the charged particles in a bent mirror is less than that in the axi-symmetric mirror. For a special bent mirror with the deflection angle of the coils α = 45°, it is found that the loss rate reaches maximum value at certain ion number density where the ion electrostatic oscillation frequency is equal to the ion cyclotron frequency. In addition, the loss rate is irrelevant to the direction of the proton beam. Our results may be helpful to devise a mirror. In order to obtain the least loss rate, we may choose an appropriate deflection angle, and have to avoid a certain ion number density at which the ion electrostatic oscillation frequency is equal to the ion cyclotron frequency.