串列加速器358型双等离子体离子源改进及性能研究

为提高北京师范大学GIC4117型串列加速器358型双等离子体离子源束流强度及灯丝使用寿命,改进了离子源灯丝涂覆材料中Ba、Sr、Ca元素的占比、灯丝涂覆方法及离子源保护措施。讨论了在不同灯丝电流下,进气量、弧流、约束磁铁电流对离子源输出束流强度的影响。灯丝累积使用寿命达到200 h以上,靶室束流强度较原来采用860A溅射源提高约500倍。同时本文对358型双等离子体离子源调试过程中的异常断弧情况进行了分析和改进。     

低能高束流氩离子源的结构及性能

离子源技术是等离子体研究中的一项重要内容,而低能大束流源则是离子源技术研究中的一个重要方向,因为这样的源在离子束刻蚀、离子束溅射镀膜以及荷能粒子与物质相互作用方面都有广泛的应用;本文采用空心阴极空心阳极结构,用热阴极电子发射弧放电驱动并用磁场约束产生等离子体,用曲面发射引出离子束,研制成了氩气放电溅射离子源;研究了灯丝加热电流、弧压对弧流的影响和弧流与工作气体压力对离子束引出的影响规律.离子源的引出电压在0-4.0 kV之间连续可调,最大引出束流为100 mA,束斑面积为φ6.0 cm,以Ti为溅射靶时的最大溅射沉积率为0.45 nm/s,离子源可连续工作160 h.     

双潘宁离子源等离子体发生器电源系统

针对强流双潘宁离子源等离子体发生器电源系统的特殊要求,介绍了灯丝电源和弧电源的组成及其作用,并对其主电路设计思路进行了相关的分析。离子源等离子体放电实验结果表明,该套等离子体电源系统达到了设计指标要求。     

HL-1M中性束注入器等离子体发生器电源

HL-1M中性束注入器和供电方框图如图1所示。注入器主要由离子源、束线和电源等部分组成,而离子源由等离子体发生器(放电室)和加减速结构(引出系统)两部分组成。在这种源型中,等离子体发生器电源包括灯丝、弧流和送气电源,也称做放电电源。     

离子源电源光电转换控制接口研制

正离子源产生的束流品质直接影响回旋加速器引出的束流优良。14 MeV强流回旋加速器采用外部多峰场离子源。离子源电源包括灯丝电源、弧压电源、等离子体电源、吸极电源,其均悬浮于30kV高压电源上。现设计一高精度、高线性、高稳定度,低噪声,自动漂移补偿的光电控制接口。通过该接口来完成控制命令的传输和电源本地信号的回采,从而实现经PLC在上位机进行控制。电路中包含供电模块、频率电压转换模块、电压频率转换模块、自动漂移补偿模块。图1为控制接     

真空弧氘离子源中杂质氕对束流品质的影响

分析了真空弧氘离子源中杂质的主要构成,并着重分析了杂质氕的成因及其对氘离子源性能的影响.对单次脉冲和低重复频率脉冲工作状态下的真空弧氘离子源进行了光谱诊断实验和核反应分析实验,结果表明,氘离子源等离子体中的确含有较多的杂质氕,可对氘离子源的引出束流品质产生较大的危害.并对如何减小杂质氕的影响提出了建议.     

CSNS强流负氢离子源及其改进

中国散裂中子源（CSNS）的离子源是1台强流负氢离子源，该离子源负氢束流的能量为50 keV，负氢流强可达40 mA，束流占空比最高为1.25%（重复频率为25 Hz，脉宽为500 μs）。目前该负氢离子源已投入到CSNS中使用。由于等离子体放电电极受带电粒子溅射的缘故，在1.5%（25 Hz，600 μs）的占空比、负氢流强30 mA运行下，离子源的寿命约为30 d。为提高离子源使用的稳定性，对离子源进行改进优化，提高了离子源的运行效率和稳定性。     

强流离子源引出系统的气压及构成材料对离子光学性能的影响

本文简单介绍了从离子源中引出束流的机制及最小角散度的离子光学条件;阐述在研制15cm双潘宁离子源(引出电压25kV、电流20A)时,所解决的二个问题,即:使得引出系统保持最佳真空度的脉冲进气方式;提出了用复合材料制造绝缘环,从而提高了电绝缘强度。这二者都对离子光学作出良好的贡献。     

强流双潘宁离子源弧特性研究

针对22cm双潘宁离子源,研究了其弧流与放电调节参数的关系以及二次进气的效果,确定了拉长弧流脉宽、提高弧流强度与稳定性、达成离子源合适工作状态的措施,为获得高品质的弧流提供了依据.离子源弧特性测试研究结果对提高强流离子源的工作性能以实现NBI系统强流准稳态运行有重要的指导意义.     

真空弧离子源脉冲工作瞬间的放电行为

采用高速摄影和光谱诊断的方法研究了真空弧离子源脉冲工作瞬间的放电行为。拍摄了离子源放电瞬间吸氢电极上阴极斑的形成过程，分析了不同放电电流时阴极斑的发射光谱。实验结果表明，当脉冲工作电流为10^1—10^2A时，真空弧离子源放电区一般只有单个阴极斑，阴极斑的位置在同一次放电中的变化很小；较大的脉冲工作电流有利于提高阴极斑的温度，并最终导致氢离子浓度的增加，但也会使阴极材料的溅射更加严重，造成离子源等离子体品质下降。     

Simulation,Design, Construction of Duoplasmatron and Diagnostic Neutral Beam System for Alborz Tokamak

Diagnostic Neutral Beam (DNB) has been used for measuring plasma parameters of tokamaks such as ion and electron temperature, safety factor, impurity concentration and etc. Ion source and electrical power supply specification are the main part of DNB. Arc discharge current value is affected by filament current and anode voltage. Beam current changes with arc current signal in our experiment that agree with theoretical relations. Sixty milli-ampere (60 mA) pulse beam current is because of arc current of about 40 A and extraction voltage of about 20 kV. The increase of beam current with arc current has been reported experimentally and effect of arc current on beam current has been investigated for several high extraction voltages. Optimum condition, which means having a telescopic beam (minimum divergence) for specific parameters of duoplasmatron, has been simulated and verified with experimental test. The best extraction voltage for these parameters has been found to be about 16-kV. The ratio of the perpendicular velocity to parallel velocity has been calculated to be about 0.012. It has been shown experimentally with optical emission spectroscopy that increase in arc current and magnetic current increase proton content of beam.     

Studies of an Expanded Plasma Front Duoplasmatron Ion Source

A new and more flexible ion source assembly has been built for continued study of a duoplasmatron with an expanded plasma front and a cylindrical Pierce-electrode extraction geometry. Studies of conditions necessary for the formation of an expanded plane plasma boundary are discussed, and progress toward the achievement of an aberration-free parallel beam of several hundred mA of protons is reviewed. Recent studies suggest that a duoplasmatron with an expanded plasma front and a diverging Pierce-electrode extraction geometry would produce significantly higher aberration-free beam currents than can be obtained with the present cylindrical geometry. The information necessary for the design of lens optics for matching such a source, or any source which produces a diverging aberration-free beam, to an accelerator or plasma containment device is provided in a convenient and comprehensive form by beam characteristic curves which give beam radius and divergence as functions of perveance at some convenient measuring plane close to the extractor for several fixed values of arc current. Data provided by a constant perveance experiment establish practical limits on obtainable beam current at the chosen design points on the characteristic curves.     

基于多元线性回归模型的中性束质子比分析

中性束质子比的高低对其注入等离子体后的加热效果具有重要的影响。实验中,强流离子源的灯丝电压、弧压、进气量等宏观运行参数决定了中性束质子比的大小。以东方超环中性束注入测试台束引出实验为基础,利用多元线性回归模型对引出中性束质子比进行分析,建立了影响中性束质子比的预测方程,并对该模型的正确性进行了检验。结果表明,中性束质子比可利用以灯丝电压和弧压为自变量的多元线性回归模型进行分析,灯丝电压是影响质子比的关键参数,弧压次之。     

用于蓝姆移动型极化离子源的低能强流双等源

建立了用于蓝姆移动型极化离子源的双等源和低能引出聚焦系统，实验比较了等离子体出口孔径和聚焦电极之间的距离对引出束的影响，并调整了离子源的运行参数。离子束的质子比可达６０％以上，满足了极化离子源的工作要求。约有４ｍＡ低能氢离子束（５５０ｅＶ）或氘离子束（１１００ｅＶ）进入铯蒸汽电荷交换管道，在极化源上使用低能强流双等源后，可获得２００ｎＡ左右的极化质子（或氘核）束。     

Electrical Parameter Measurement System of the Ion Source for EAST Neutral Beam Injector

Neutral beam injection (NBI) is recognized as one of the most effective means of plasma heating. A virtual instrument (VI) has been designed to provide electrical parameter measurement for the ion source of EAST-NBI. The VI is written using the National Instruments LabVIEW graphical programming language. All data acquisition (DAQ) is accomplished using ADLINK DAQ hardware interface and Task-oriented DAQ Driver. The VI can measure filament voltage, filament current, arc voltage, arc current and accelerating voltage etc. The data obtained from the VI are feedback of the ion source operation state and helpful to direct the operation parameter optimization of the ion source.     

大功率离子源负载端数据采集系统研制

大功率离子源是整个中性束注入装置的核心部件。离子源灯丝、弧等关键部件的运行状态对系统实验参数设定、故障判断至关重要。为了实时监控灯丝、弧的运行状态,设计了一款大功率离子源负载端数据采集系统。系统采用伏频(V/F)转换技术实现了采样信号的远程隔离传输。PXI系统和Lab VIEW将采样信号进行实时显示。实验结果表明,在直流和调制注入模式下,系统实现了离子源灯丝和弧电压的远程实时监控。     

Study the Characteristic of the Hot Cathode of High Current Ion Source

The difference of hot cathode operation mode has great influence on the arc discharge of high current ion source. Based on the analysis of the theory of hot filament with two operation modes and combined with ion source experiments, the paper studies the effects of hot filament operation modes on ion source arc discharge.