支持多种温度传感器的多通道低温测量系统的设计

中性束注入(neutral beam injector, NBI)系统的低温泵上必须设置一组温度测量点以监控其工作状态;为满足NBI温度测量需求,设计了一种支持多种温度传感器的多通道低温测量系统;系统采用24位Σ-Δ模数转换(analog-to-digital converter, ADC)芯片AD7193执行模数转换,采用控制器STM32F103ZET6控制设定恒流源、切换测量通道、ADC、以太网通信、串口通信、温度数据处理以及其他控制电路;该温度测量电路的设计可以用于由恒流源驱动的四线制低温温度测量领域。     

Control System of Neutral Beam Injection on HT-7

Neutral Beam Injection control system (NBICS) is constructed to measure the plasma current, Magnet current, vacuum pressure, cryopump temperature, control water cooling, filament voltage, and power supply， etc. The NBICS, consisting mainly of a Programmable Logic Controller (PLC) subsystem, data acquisition and processing subsystem and cryopump and vacuum pressure monitoring subsystem, has successfully been used on a NBI device. In this article, the design of NBICS on HT-7 is discussed and each subsystem is described in particular.In addition, some experimental results are reported which are very important data for further research related to the HT-7 tokamak.     

The Progress of a Microbeam Facility in the Institute of Plasma Physics

The progress of a microbeam facility in the institute of Plasma Physics was discussed in this paper.This kind of equipment can supply single-particle beam which may be implanted into cells in micrometer-radius and measured by a new outstanding detector among global microbeam systems.Measurements by some plain targets showed that the highest current after the accelerator tube can be larger than 20μA ,the H2^ current before the second bending magnet is near 0.9μA ,the current after the second bending magnet is near 0.8μA,and the current of the beam line(after a 2-mm diameter aperture)is near 0.25nA which is enough for the single-particle microbeam experiment.It took scientists 3 months to do their microbeam experiment after setting up the qccelerator beam line and get the microbeam from this equipment.Two pre0collimators were installed between the 2-mm diameter aperture and the collimator to survey the beam.Tracks on the CR39 film ectched in the solution of NaOH showed that the beam can go through the collimator including a 10μm diameter aperture and the 3.5μm thick vacuum sealing film(Mylar).A new method,which is called optimization of the beam quality,was put forward in this paper,in order to get smaller diameter of beam-spot in microbeam system.     

The Experiment of Obtaining Micron Beam in the Single-Particle Microbeam Facility of the Institute of Plasma Physics

The Experiments, methods and results of obtaining micron beam in the Microbeam Facility of the Institute of Plasma Physics were discussed in this paper. The H2^ beam was accelerated by the Van de Graa/f electrostatic accelerator, and the collimator at the end of the beam line is a 60μm thick stainless steel chip. And as a result, particle tracks on the solid track probes (CR39 film) etched in the solution of NaOH showed that the beam can go through the collimator with a small aperure (2000, 300, 55, 30, or 10μm) and 3.5μm thick vacuum film(Mylar). Besides the CR39 method, the beam was measured by an energy spectrum detector after the 10μm diameter aperture and the 3.5 μm thick vacuum film too.     

中性束注入器Tank充气特性对离子源放电的影响

利用对PV-10型压电阀定标实验,研究了中性束注入器Tank内补充气体的参数对离子源放电弧电流的影响,对比压电阀脉冲电源的脉宽和幅值,显示后者对Tank内补充气体量具有更显著的线性关系.据此进行的中性束注入器离子源放电实验结果表明,采用压电阀定标值计算获得的参数,可以稳定重复地获得最大放电脉宽达到400 ms的等离子体弧电流,为下一步向托卡马克装置注入高能中性粒子束奠定了应用基础.     

EAST-NBI用差分式低温冷凝泵的设计

为了维持EAST-NBI内的真空环境以满足中性束生成与传输过程对真空压力分布的要求,设计了EAST-NBI用差分式低温冷凝泵.本文概述了中性束注入加热的原理以及EAST-NBI真空系统的组成,详细阐述了EAST-NBI用差分式低温冷凝泵的结构设计,抽速和冷凝面积的确定,液氦系统和液氮系统热负荷的计算等关键问题.该差分式低温冷凝泵通过在EAST-NBI综合测试台上进行大量实验验证,完全满足EAST-NBI对真空系统的要求.     

射频负离子源关键参数测量系统研制

强流离子源是大功率中性束注入系统的关键部件之一,为了实现中性束注入系统的稳态运行,需要开展射频负离子源的实验研究。射频负离子源的负离子引出电流、引出总电流和引出电子流等关键参数的测量是射频离子源实验理论分析的基础,本系统通过信号调理隔离传输实现射频负离子源关键参数的测量。实验结果表明,系统测量采集数据精准可靠,运行稳定。     

静电场分析法优化设计负离子源中性束注入系统高压仓结构

为探究最为合理的负离子源中性束注入(NNBI)装置高压仓(HVD)结构,采用有限元静电场分析方法,对不同结构高压仓进行仿真计算分析,在考虑分布电容影响的前提下,优化设计了高压仓的主体和外形结构,并确定了安全绝缘距离,对高压仓的工程研制提供了理论指导,为NNBI的安全稳定运行奠定了基础。     

HT-7诊断中性束装置真空远程监控系统设计

本文介绍了真空实时远程监控系统的设计要求,讨论了该系统的硬件设计、软件设计及其工作原理,给出了部分实验结果。系统成功地应用于实验并获得理想的实验结果,为诊断中性束稳态运行提供可靠保障。     

诊断中性束装置离子源起弧实验的多元非线性回归分析

通过调节影响诊断中性束离子源弧流的进气量、灯丝电流和弧压三个参量，进行了三组离子源起弧实验。建立了多元非线性回归模型，得到了三个参量对弧流的回归方程。回归分析表明，弧流对进气量和灯丝电流相当敏感，且有趋于饱和的特征，这与实验结果相吻合。在进气针阀开度492、灯丝总电流469A、弧压190V时重复起弧，均得到弧流170A以上、脉宽150ms的稳态放电，满足了诊断中性束流对弧流的要求。