静电双圆筒透镜、单透镜的一种传输矩阵计算方法

在高压型多种加速器里,常用双圆筒和单透镜对束流进行加速和聚焦,这两种电透镜又经常被安装在离子源引出电极附近,这里粒子所获得的能量低,束流较强,空间电荷效应明显。文献[1、2]较好地讨论了某些电透镜中束流光学的一种传输矩阵法,文献[3—5]用成象光学法讨论了双圆筒、单透镜的成象光学参数;文献[6—8]用求解Laplace方程的方法将等径     

图形显示直线加速器与静电加速器粒子动力学计算程序LEADS

计算机程序ＬＥＡＤＳ用ＭＳＦＯＲＴＲＡＮ５．１写成，约６６００个语句，适合在ＩＢＭＰＣ及其兼容机上运行。程序可计算由三圆筒单透镜、三膜片单透镜、双圆筒透镜、均匀场静电加速管、磁四极透镜、电四极透镜、偏转磁铁、单间隙射频加速元件、双间隙射频加速元件（一般指ＱＷＲ结构）和三间隙射频加速元件（一规能ＳＬＲ结构）组合而成的离子光学系统。程序采用多粒子跟踪与σ矩阵相结合的万式，用ＭｏｎｔｅＣａｒｌｏ方法随机产生初始相空间中各代表点的坐标，并用Ｐｏｗｅｌｌ非线性最优化方法进行光路系统的最优化计算。计算结果可以在微机屏幕上直观地显示出来。     

磁四极透镜测量装置的研制

本文介绍一台测量磁四极透镜的磁中心和各次谐波的测试仪器和设备。它是采用旋转长线圈的方法来测量四极透镜孔径内场形分布,测量线圈长500 mm,线圈的旋转速度为     

高分辨高纯锗低能光子探测器研制

用硼离子注入方法制备P~+电极,采用沟槽形结构,成功地研制出高分辨高纯锗低能光子探测器。4个有代表性的探测器能量分辨率分别为FWHM=183,178,165,162eV。探测器灵敏体积分别为φ16mm×12mm,φ13mm×10mm,φ13mm×9.7mm和φ13mm×9.5mm。此4个探测器的性能达到了国际先进水平。     

极尖断面为折线的四极透镜磁性能研究

对传统双曲线极尖的四极透镜进行了磁性能分析。在此基础上，提出了极尖断面为折线的四极透镜结构。磁场的数值分析以及测量结果表明：该结构产生的场梯度均匀，且具有磁场集中、磁场梯度高、便于加工和安装的对称性控制等优点。该结构的四极透镜已用于ＣＹＣＩＡＥ－３０回旋加速器和ＨＩ－１３串列加速器束流输运线之中     

三合透镜系统的腰腰传输图解法

一、引言众所周知,由两个极性相反的四极透镜所组成的双合透镜以及由三个极性相互交替的四极透镜所组成的三合透镜系统,可以在两个方向上实现聚焦,它们常常被用来聚焦束流或实现束流横向相空间的匹配。由于双合透镜在结构上比三合透镜简单,在束流输运系统中,一般多采用双合透镜系统。但是,三合透镜在x,y两方向较对称,如果要求所设计     

一种用于X射线源剂量率监控的小尺寸穿透电离室

一种用于X射线源剂量率监控的小尺寸穿透电离室，涉及辐射检测技术领域。本发明由电离室体、绝缘套管和接线盒组成。接线盒位于绝缘套管的一端，电离室体固定在绝缘套管内。电离室体和绝缘套管的沿着射线方向的两个面上都刻有开槽。电离室体内形成密闭的灵敏区，两根电极管固定在灵敏区内。电极管与充气管相连。充气管穿过同轴的后陶瓷管和前陶瓷管伸入灵敏区，它的另一端置于接线盒内。通过软线分别将从保护环上引出的镍丝和螺钉、充气管连接到第一插座和第二插座用于输入高压和输出测量信号。本发明在环境适应性好、测量精度高的基础上，可以使穿透电离室的尺寸大大减小，从而可以安装在加速器的钨屏蔽体中，减小散射。     

裂变电离室极间电场计算

正堆用裂变电离室电极结构通常有多层平板型结构和同轴圆筒结构等,两种结构原理基本相同。为保证足够的电极涂镀面积,同轴圆筒电极需有一定的长度,这样电极筒容易受外界设备振动的影响。相对于圆筒电极,多层平板电极结构中每层电极片尺寸较小,电极片受外界设备环境振动的影响较小,因此结构的抗振性更好。针对这两种结构,对电离室极板间的电场分布进行计算。计算使用Maxwell 16.0完成,极板间的距离设定为2 mm,极间所加电压为     

HPGe探测器对圆形面源探测效率的研究

实验刻度了GEM60P4型高纯锗(High Purity Germanium,HPGe)探测器在H=250mm处对三种圆形面源(φ24 mm、φ80 mm和φ90 mm)的峰探测效率,结果表明,这三种源的效率基本一致。采用MCNP模拟了φ40–160mm内的圆形面源效率,研究了探测效率随样品直径的变化关系,并采用Geant4计算了圆形面源对同轴探测器的有效立体角。对φ90mm以上的样品源,探测效率随源直径的增大在逐渐减小,且高能γ射线效率减小程度较快,需采用标准源进行效率刻度。     

BRISOL谱仪关键技术研究

HI-13串列加速器升级工程在线同位素分离器（BRISOL）需对同质异位素进行分辨,谱仪设计质量分辨率为20 000,是很高的技术指标,对离子源、高压、分析磁铁、四极透镜等设备均有很大的挑战。本文详细介绍了BRISOL谱仪关键技术及其测试结果。能散对谱仪的质量分辨率影响较大,BRISOL谱仪设计采用异能大小铁结构消除能量色散。离子源采用表面离子源,并采用三电极引出系统,中间电极电压可调用以优化束流品质,优化后离子束RMS发射度好于3.8 πmm•mrad。分析磁铁采用表面线圈进行磁场垫补,垫补后积分场均匀性好于3.5×10^-5。为修正像差,大分析磁铁安装了β线圈和γ线圈,同时,在分析磁铁前后共设置了4台电六极透镜。     

J-2.5MV静电加速器加速管的研制

介绍了为２．５ＭＶ静电加速器研制的加速管的结构特点和性能测试结果。该加速管已成功地用于国产Ｊ－２．５ＭＶ质子静电加速器上,性能稳定可靠。     

TUNL高分辨率核物理实验的能量刻度和校正

一、引言TUNL(Triangle Universities Nuclear Laboratory)是世界上著名的高分辨率实验室之一。该实验室的4 MeV静电加速器在独特的能量稳定系统及PDP-11计算机控制下,可     

Analysis and Optimization of Stability of CAS-LIBB Single Ion Microbeam

Single ion microbeam is the most advanced technology which can emit a single ion for precise localization. A single-ion microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering （LIBB）, Chinese Academy of Sciences （CAS）, with a spatial resolutions of about 5 μm. Based on CAS-LIBB microbeam, three key elements affecting the quality of the system are assessed： the size of beam spot, the energy range and the counting accuracy of implanting ions. Various contributions to the ion beam stability, including the ion source, the terminal voltage of electrostatic accelerator and the components in beam pipeline, are discussed. Analysis shows that the improvement of terminal voltage stability is the most important issue for future optimization of CAS-LIBB facility. Some preliminary investigations and project aimed at optimization and development are proposed as well.     

Evaluation of activated area in the electrostatic accelerator facilities

In order to clear the activated area in electrostatic accelerator facilities,four accelerator facilities were selected and typical neutron emission experiments were performed.Neutron flux during operation and induced activity caused by charged particles on the accelerator and its surrounding area after irradiation were measured.Also the monitored neutron flux and calculated value by Monte Carlo calculation using PHITS code were compared.It was confirmed that the results between calculated data and measured data showed the good agreement with each other.Finally,it was concluded that we have to take care the activation of beam line and target.But,it is not necessary to treat accelerator tank,surrounding materials,and building concrete as radioactive materials in case of decommissioning.     

A model for electrical fast transient analyses of the ITER NBI power supplies and the MAMuG accelerator

The design of ITER Neutral Beam Injector (NBI) is based on a five-stage electrostatic accelerator, known as Multi-Aperture Multi-Grid (MAMuG) and characterised by an overall acceleration voltage of ?1 MV. The MAMuG accelerator requires a five-stage power supply system under strict load protection requirements, being subjected in operation to breakdowns. In this paper a circuit model of ITER Neutral Beam Injector power supplies and MAMuG accelerator is illustrated, for the simulation of fast transients related to accelerator breakdowns in particular. Consideration of the high voltage involved and of the complex inductive and capacitive couplings implied careful assessment of stray parameters by calculations with finite element techniques. The circuit model, developed to address a number of design issues requiring simulations at system level, is now ready for use—the optimisation of passive protections being the most significant application.     

加速器间隙透镜电压稳定装置的研制

在５ＳＤＨ串列静电加速器中，采用串联电压补偿方法对间隙透镜１６ｋＶ电压进行稳定，从而提高了束流的稳定性，并明显延长了注入系统的使用寿命。     

Characteristics of a Surface Contact Hall Current Accelerator

An electric propulsion device is described which utilizes surface contact ion generation followed by space-charge-neutralized, electrostatic ion acceleration in an annular, low-density, Hall current accelerator. Performance analyses and design criteria are presented to illustrate the potentialities of the device for use as an efficient, high-thrust-density engine in the intermediate specific impulse regime. Preliminary experimental data obtained with a laboratory model are presented.     

A Study on the Vibration of the Charging Belt in an Electrostatic Accelerator

1. IntroductionAn electrostatic arcelerator ascelerates particlesby the extremely high electrostatic voltage (up toMV order) which is produced by charging the stain-less steel ball--like terminal [l]. The charging beltis designed for transferring the charge to the terminal. A special circuit sprays the charge to the beltthrough a row of pins, then the beIt picks up thecharge and transfers it to the terminal continuously.The jitter of the belt directly influences the pick--upof the charge, so…     

200keV直流/脉冲中子发生器束流输运模拟计算

计算机模拟计算在各种类型加速器的设计中起着很重要的作用。例如,计算机模拟很快就可以确定加速器各部件的最佳工作参数和所需要的光学条件,使一台加速器复杂的束流输运系统设计变成简单的工作。TRANSPORT程序是当今世界上关于束流输运计算的最优秀程序之一。但是,该程序不能进行静电加速器离子光学系统的计算,也不能作直线加速器的粒子动力学计算。为此从北京大学引进了LEADS程序,它不仅具有TRANSPORT程序的优点,还克服了其不足。对含有聚束(脉冲束流)系统的加速器粒子动力学进行模拟是LEADS程序的新特色。实验中用LEADS程序模拟了200keV直流/脉冲中子发生器束流输运过程,得到了横向相图、纵向相图和束包络图。还用LMOV程序计算和验证了聚束系统,束流脉冲波形图和实验结果比较接近。     

Status of the New Zealand tandem accelerator mass spectrometry facility

A tandem accelerator mass spectrometry system is being installed at the Institute of Nuclear Sciences, and will become operational this year. Laboratories for ¹⁴C dating and low level radioactivity counting have been established here for several years, and the advent of the accelerator technique is expected to widen significantly the scope of investigations using these facilities, as well as open up new research possibilities. Oceanographic and atmospheric studies in particular are seen as fields where accelerator mass spectrometry can be fruitfully employed.The system being developed is similar to that at Zürich, and is based on a type EN tandem Van de Graaff, with magnetic and electrostatic beam analysis, and sequential acceleration of isotopes under computer control.Techniques have been developed for the conversion of carbonaceous material to graphite, for ¹⁴C dating, and the extraction of beryllium from sediments for ¹⁰Be measurements.