中国散裂中子源RCS注入区H0CT测量系统研制

中国散裂中子源的强流质子加速器采用剥离注入的方式,碳膜将H^-剥离两个电子后变成质子,多圈涂抹注入到快循环同步环加速中,并加速至1.6 GeV。为了精确测量剥离膜的剥离效率并研究不同厚度剥离膜的使用寿命,在I-Dump束线上新研发并安装了一套束流流强探测器(H⁰CT),用于测量未完全剥离的H^-和H⁰(H^-被剥离一个电子)粒子。为了测量μA级束流,H⁰CT弱流强测量系统的研制考虑了外部干扰,配合探头、线缆及电子学低噪声的抗干扰设计,将环境噪声及干扰的影响降至最低,提高信噪比,实现了μA级脉冲电流的测量。     

中国散裂中子源快循环同步加速器主剥离膜设计

设计了中国散裂中子源(CSNS)快循环同步加速器(RCS)注入区的主剥离膜装置。为降低研制难度和成本，提高运行可靠性，选择了回转体式的结构。根据在线可调性、高稳定性、高定位精度和超高真空等技术难点，给出了CSNS/RCS主剥离膜的具体结构方案和控制方案。利用ANSYS有限元分析软件和材料力学原理，对设备的核心部件不锈钢同步带进行了模拟计算和理论分析。     

7MeV注入剥离膜系统设计

设计了一台注入能量为7 MeV的快循环同步加速器剥离膜装置,介绍了主体结构设计及高精度换膜运动结构,实现膜片精确定位及在线换膜功能。针对注入参数对膜片开展分析计算,分析了7 MeV的负氢离子束注入时相应的碳膜材料的反应截面及不同厚度的剥离效率,给出了膜片厚度的参数选择。对所设计膜片的温升和寿命进行分析,膜片的温升最高点达到755 K,远小于同类的加速器的剥离膜温度,具有更高的寿命和可靠性。     

中国散裂中子源快循环同步加速器壁电流探测系统

在中国散裂中子源工程中, 快循环同步加速器负责将剥离注入的能量为80MeV的质子束加速至1.6GeV后引出。在快循环同步加速器上共安装了两台壁电流探测器, 用来观测束流从注入至引出过程中束团在时域上的变化情况。详细介绍了壁电流探测器在陶瓷间隙、磁性材料和匹配电阻等方面的设计考虑, 以达到带宽满足百kHz到30 MHz的设计目标, 并对实际带束流测量结果进行分析讨论。经实际在线运行测试, 此壁电流探测器完全满足束流调试及运行需要。     

CSNS反角白光中子源束线控制系统研制

中国散裂中子源(CSNS)反角白光中子源束线主要由中子束窗、中子开关、中子准直器和真空管道等组成。为了保证CSNS反角白光中子源束线安全、稳定、可靠地运行,研制了基于EPICS(Experimental Physics and Industrial Control System)软件架构的控制系统。该系统主要由中子束窗、中子开关及中子准直器的运动控制系统、真空控制系统和控制室三部分组成,实现了对反角白光中子源束线主要设备的远程监测和控制。测试结果表明,该系统具有稳定可靠性高、人机交互友好的特点,很好地满足了反角白光中子源束线运行的需要。     

散裂中子源与中子散射

文章介绍了散裂中子源的物理基础、中子散射用散裂中子源对加速器的要求和靶系统的特点，阐述了利用散裂源，尤其是脉冲散裂源进行了散射实验的主要优点，并对我国建造散裂中子源的发展战略提出了建议。     

CSNS加速器真空控制系统的设计与实现

中国散裂中子源(CSNS)加速器真空控制系统负责真空数据采集、设备监控和闸板阀控制与联锁,是设备运行和故障诊断以及超高真空保持的重要保障。本文介绍了加速器真空需求,基于实验物理及工业控制系统EPICS软件框架的真空控制系统设计与实现,使用横河可编程逻辑控制器PLC控制与联锁设备,摩莎MOXA工控机监测真空状态,EPICS PV数据直接进入声音报警系统和历史数据库系统,为工作人员及时发现和处理问题、进行后续数据分析和机器研究等提供了便捷途径和可靠保障。目前,该系统已完成现场安装和调试,并已正式投入运行。运行结果表明,该系统具有稳定性好、可靠性高、人机交互友好的特点,很好地满足了加速器真空控制系统运行的需要。     

中国散裂中子源首次打靶成功

<正>位于广东东莞的中国散裂中子源(CSNS)首次打靶成功,这表明加速器和靶站设计合理,证明了各项设备加工制造与安装调试的高质量和高可靠性。这标志着中国散裂中子源主体工程顺利完工,进入试运行阶段,这是科技领域里的重大里程碑。建成后的CSNS将成为世界第四台脉冲式散裂中子源,在材料科学和技术、生命科学、物理、化学化工、资源环境、新能源等诸多领域具有广泛应用前景。CSNS将是国际前沿的高科技、     

第二届散裂中子源多学科应用研讨会简讯

散裂中子源是基于质子加速器产生的高能质子轰击重金属靶造成重金属原子散裂从而提供高脉冲中子通量的平台型大科学装置，散裂中子源在众多学科领域，特别是物质科学领域得到了广泛的应用，结合目前正在筹备阶段的北京散裂中子源（BSNS）项目的“第二届散裂中子源多学科应用研讨会”于2005年7月27日—29日在北京中国科学院物理研究所召开。     

CSNS RCS注入横向相空间涂抹的研究

中国散裂中子源(CSNS)加速器系统由80MeV的直线加速器和1.6GeV的快循环同步加速器(RCS)构成. CSNS第一阶段采用H^－剥离注入方法, 将粒子数累积至1.88×10¹³. 注入束流被涂抹在较大的横向相空间内, 以减小空间电荷效应. 粒子注入后, 为了降低由空间电荷效果引起的工作点漂移和工作点弥散, 束流分布的均匀性很重要. 引入了评估束流分布均匀性的三个参数. 为了抑制注入过程中束流发射度和束晕的增长, 通过采用三维的模拟程序ORBIT, 对不同的横向相空间涂抹方案进行了比较. 同时还介绍了工作点、注入峰值流强和斩波调制比等因素对注入过程的影响.     

HCSB DEMO 中子通量谱分析及活化片法测量系统概念设计研究

利用蒙特卡罗粒子输运程序(MCNP)对氦冷固态增殖剂包层聚变示范堆(HCSB DEMO)做了中子通量谱分析。根据中子通量谱特点选出活化片材料,根据跑兔系统和活化片法测中子通量的原理设计出适用于测量HCSB DEMO 增殖包层中子的活化片法测量系统,并对其各组成部分及功能做了说明。计算了活化片在测量系统辐照端辐照时的活化反应率、活化片特征γ 射线发射率及特征γ 计数率,并得到一套合理的测量方案,用于HCSB DEMO 包层中子的测量。     

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利用蒙特卡罗粒子输运程序(MCNP)对氦冷固态增殖剂包层聚变示范堆(HCSB DEMO)做了中子通量谱分析。根据中子通量谱特点选出活化片材料,根据跑兔系统和活化片法测中子通量的原理设计出适用于测量HCSB DEMO增殖包层中子的活化片法测量系统,并对其各组成部分及功能做了说明。计算了活化片在测量系统辐照端辐照时的活化反应率、活化片特征γ射线发射率及特征γ计数率,并得到一套合理的测量方案,用于HCSB DEMO包层中子的测量。     

Performance improvements with advanced design foils in high-currentelectron beam diodes

A design for the vacuum/pressure barrier of an electron-beam diode ready to be fielded on a large krypton-fluoride excimer laser is described. The barrier is a composite foil, fabricated from carbon fibers, Kapton-membrane, epoxy, and copper foil. This composite foil has advantages over more traditional metal foils, exhibiting particularly high tensile strength and a high modulus of elasticity. Other important properties of these composites for use in KrF excimer laser applications include: high electron transmission with low loss to scattering, chemical compatibility with fluorine, low porosity, and low reflectivity in the ultraviolet. The mechanical properties of the composite foil allow the design of support structures (hibachis) which incorporate larger openings than are possible with metal foils with similar electron transmission characteristics     

Experimental study of the plasma window

The plasma window is an advanced apparatus that can work as the interface between a vacuum and a high pressure region. It can be used in many applications that need atmosphere-vacuum interface, such as a gas target, electron beam welding, synchrotron radiation and a spallation neutron source. A test bench of the plasma window is constructed in Peking University. A series of experiments and the corresponding parameter measurements have been presented in this article. The experiment result indicates the feasibility of such a facility acting as an interface between a vacuum and a high pressure region.     

与散裂中子靶物理相关的理论计算程序探讨I薄靶计算

利用中能强流质子加速器形成的散裂中子源作为外加中子源驱动次临界反应堆的洁净核能系统是目前国际上的一个研究热点 .散裂中子源是这个系统的一个重要部分 ,也是一个急需解决的重点.有关散裂靶物理的理论计算程序的建立和基准检验是目前工作的一个重点.The research for intermediate energy proton accelerator driven radiologically clean nuclear power system has attracted considerable attention. The spallation neutron source induced by intermediate energy proton nucleus interaction is a key point and has not solved yet for the transmutation and applications. The theoretical programs related to the spallation neutron source for accelerator driven system (ADS) are discussed at present work.     

HI－13串列加速器的改进

本文总结了ＨＩ－１３串列加速器投入运行以来所做的各项改进工作及国产化情况． Imptovements on HI-13 tandem accelerator which have been made since 1986 are summerized. Modifications and home made components for the injector, the vacuum system, the foil stripper system,the laddertron charsing system and beam lines are described.     

The measurements of thermal neutron flux distribution in a paraffin phantom

The term ‘thermal flux’ implies a Maxwellian distribution of velocity and energy corresponding to the most probable velocity of 2200 m s^???1 at 293.4 K. In order to measure the thermal neutron flux density, the foil activation method was used. Thermal neutron flux determination in paraffin phantom by counting the emitted rays of indium foils with two different detectors (Geiger–Muller counter and NaI(Tl)) was the aim of this project. The relative differences of the outcome of the experiments were between 2.5% and 5%. The final results were compared with MCNP4C outputs and the best agreement was generated using NaI(Tl) by a minimum discrepancy of about 0.6% for the foil placed 8.5 cm from the neutron source.     

Neutron field mapping and dosimetry by CR-39 for radiography and other applications

A neutron telescope based on the n–p elastic scattering on H is suggested to investigate the inhomogeneity of neutron fields used for different applications like neutron radiography, biological investigations or dosimetry where the number of neutrons with high energy (above 8 MeV) is negligible. The telescope consists of a thin polyethylene foil and a track etch detector divided by an air gap and placed inside a glass tube which can be evacuated by a simple vacuum pump. The angular and energy resolution of the telescope mostly depend on the diameter of the tube, the length and pressure of the air gap, on the thickness and H content of the radiator and on the type of the track detector. The response of the telescope is characterized by several parameters: the incident angle distribution of protons, the length and the minor diameter distributions of the etched tracks. The response was calculated for several assemblies by a Monte Carlo code and based on the results, three different experimental telescopes were constructed and tested. The most suitable one was selected for routine measurements.     

质子入射散裂产物理论研究方法探讨

简要介绍了几种关于中高能质子入射引起散裂反应产物理论计算的方法,以及这些方法的最新发展.比较了这些方法在理论计算中的特点,指出经典外推方法有局限性,量子分子动力学方法和改进后的M C方法的计算结果与实验数据有较好的符合,但是计算量大,而且量子分子动力学方法在与宏观输运理论连接上存在不少的困难.半经验计算方法已经取得了初步的成果,需要根据新的实验结果来对其进行发展. The analysis on spallation product of proton-induced reaction with intermediate energy has important applications, such as astrophysics, biophysics, spallation neutron source, and accelerator-driven system (ADS) etc. In recent year, some theoretical models have been developed to investigate this reaction processes. At present work, we introduce the extrapolated classic theory, the quantum molecule dynamic (QMD) plus statistical decay and fission models, the method of Mento-Carlo and Smiempirical method for...