尼尔逊离子源重离子束流的发射度

尼尔逊离子源已广泛地应用于重离子加速器、同位素分离器及研究用离子注入机。用于C-600离子注入机的尼尔逊离子源,目前已获得达100μA的三十余种重离子束,其中有近二十种固体元素。     

微波离子源聚焦离子束光学系统的研究

设计了一种微波离子源的聚焦离子束光学系统,分析计算了光学系统的束径。并数值模拟了由空间电荷作用造成的束径增宽效应,找出了影响束斑大小的主要因素和减小束径的方法。测试结果表明,在束能在２５ｋｅＶ时,束流为１４８ｎＡ,束径约为２０μｍ左右。     

EAST-NBI离子源电极打火分析及处理

强流离子源是EAST(Experimental Advanced Superconducting Tokamak)中性束注入器(Neutral Beam Injector,NBI)最关键的核心部件,其能达到的性能在很大程度上决定了EAST中性束注入器所能达到的指标。离子源在束引出时电极打火现象偶有发生,这对于离子源的正常运行有非常严重的影响,甚至危害离子源的寿命。本文结合离子源运行过程中的束引出实验波形和水流量热计(Water Flow Calorimetry,WFC)系统的测量数据得出等离子体发射面的束流光学系统一直处于非最佳聚焦状态是导致打火的原因,试通过优化高压投入时刻等离子体与高压的匹配,实现高压的稳定投入有效抑制打火现象的发生,并且给离子源加入硬件保护机制,为离子源安全稳定运行奠定基础。     

The effects of beam line pressure on the beam quality of an electron cyclotron resonance ion source

The results of a series of measurements studying the possibility to use neutral gas feeding into the beam line as a way to improve the quality of the heavy ion beams produced with an electron cyclotron resonance ion source (ECRIS) are presented. Significant reduction of the beam spot size and emittance can be achieved with this method. The observed effects are presumably due to increased space charge compensation degree of the ion beam in the beam line section between the ion source and the analyzing magnet. This is the region where the neutral gas was injected. It is shown that the effects are independent of the ion source tuning. Transmission measurements through the beam line and K-130 cyclotron have been carried out to study the effects of improved ion beam quality to the transmission efficiency.     

弗里曼源热阴极弧放电在高温下应用中的几个问题

介绍弗里曼源在典型气体流量下弧室内、源缝口侧、引出缝口后３００ｍｍ处和监控处的真 空度间的关系,纯灯丝热和弧放电热引起的弧室内壁、料炉末端的温升分布特性,以及微渗水 蒸汽使高温灯丝氧化对放电特性的影响。同时研究了几种特殊气体放电的氦离子辅助以及灯丝 电极夹下垂引起的灯丝外短路问题。     

溅射负离子源靶的制作与使用

研究制作了多种溅射负离子源靶,在2×1.7MV串列加速器上采用Middleton-Ⅶ型溅射负离子源引出了流强大、稳定的30多种元素的负离子束。探讨了靶的材料、形状和尺寸等因素对束流质量的影响,以及如何通过控制铯蒸汽、电离器电流、靶压和靶位等来改善束流的质量,提高靶及电离器的寿命,降低源体的污染等。     

RADI—A RF source size-scaling experiment towards the ITER neutral beam negative ion source

IPP Garching is currently developing a negative hydrogen ion RF source for the ITER neutral beam system. The source demonstrated already current densities in excess of the ITER requirements (>200 A/m² D⁻) at the required source pressure and electron/ion ratio, but with only small extraction area and limited pulse length. A new test facility (RADI) went recently into operation for the demonstration of the required (plasma) homogeneity of a large RF source and the modular driver concept.The source with the dimension of 0.8 m × 0.76 m has roughly the width and half the height of the ITER source; its modular driver concept will allow an easy extrapolation in only one direction to the full size ITER source. The RF power supply consists of two 180 kW, 1 MHz RF generators capable of 30 s pulses. A dummy grid matches the conductance of the ITER source. Full size extraction is presently not possible due to the lack of an insulator, a large size extraction system and a beam dump.The main parameters determining the performance of this “half-size” source are the negative ion and electron density in front of the grid as well as the homogeneity of their profiles across the grid. Those will be measured by optical emission and cavity ring down spectroscopy, by Langmuir probes and laser detachment. These methods have been calibrated to the extracted current densities achieved at the smaller source test facilities at IPP for similar source parameters. However, in order to get some information about the possible ion and electron currents, local single aperture extraction with a Faraday cup system is planned.     

Use of a duoplasmatron ion source for negative ion generation

The use of electronegative species as primary ions considerably enhances the emission of positive secondary ions in SIMS. Considering furthermore that negative primary ions can be required due to instrumental configurations (e.g. the Cameca NanoSIMS 50 requires an opposite polarity of the primary and secondary ions), O⁻ ion bombardment is employed in SIMS analysis. These O⁻ ions are typically created in a duoplasmatron source, which suffers however from its low brightness and which is thus not suited for high resolution imaging applications. The development of new (electro)negative ion sources is thus necessary to optimize the analysis of electropositive elements in terms of lateral resolution and sensitivity.In this paper, we present the performance of a duoplasmatron ion source generating F⁻, Cl⁻, Br⁻ and I⁻ ion beams. In particular, we experimentally determine on a dedicated test bench the brightness of the source in the F⁻, Cl⁻, Br⁻ and I⁻ modes as a function of the gas pressure, the magnetic field strength and the arc current in the source. The obtained results are compared to the performances of the duoplasmatron in the standard O⁻ mode. In this context, a five times higher brightness was found for F⁻ (200 A/cm² sr) compared to the standard O⁻ (42 A/cm² sr).     

微波离子枪离子束光学的数值模拟

用数值模拟方法研究了聚焦离子束系统中微波离子枪的束光学性能，将离子枪看作由源等离子体极和Ｏｒｌｏｆｆ－Ｓｗａｎｓｏｎ透镜组成的双级加速系统，分析了各参对束发射特性的影响。结果展示出引出束光学主要取决于引出导流系数和电势分布，在一定条件下可获得发散度小的离子束。     

Production of intense highly charged ion beams by IMP 14.5 GHz electron cyclotron resonance ion source

A new 14.5GHz Electron Cyclotron Resonance(ECR) ion source has been constructed over the last two years.The source was designed and tested by making use of the latest results from ECR ion source development ,such as high mirror magnetic filed,large plasma volume,and biased probe.140μA of O^7 ,185μA of Ar^11 and 50 μA of Xe^26 could be produced with a RF power of 800W, The intense beams of highly charged metallic ions are produced by means of the method of a metal evaporation oven and volatile compound throuth axial access,The test results are 130μA of Ca^11 ,70μA of Ca^12 and 65 μA of Fe^10 ,The ion source has been put into operation for the cyclotron at the Institute of Moderm Physics(IMP).     

First results of negative ion extraction with Cs for CRAFT prototype negative beam source

In order to understand the physics and pre-study the engineering issues for radio frequency(RF)negative beam source, a prototype source with a single driver and three-electrode accelerator was developed. Recently, the beam source was tested on the RF source test facility with RF plasma generation, negative ion production and extraction. A magnetic filter system and a Cs injection system were employed to enhance the negative ion production. As a result, a long pulse of 105 s negative ion beam with current density of 153 A m-2 was repeatedly extracted successfully. The source pressure is 0.6 Pa and the ratio of co-extracted electron and negative ion current is around0.3. The details of design and experimental results of beam source were shown in this letter.     

Development of laser ion source for heavy ion applications

We have been developing a high-performance laser ion source (LIS) for practical applications since 2009. Ideally, the LIS should generate a carbon beam with a peak current of 20 mA and a pulse duration of over 1 μs. We selected a Nd:YAG laser with a Gaussian-coupled resonator as the laser source based on our experience of generating high-charge-state ion beams. This laser can produce fundamental pulses with a power of 650 mJ and durations of about 6 ns. The graphite target used is 10 cm high and 10 cm in diameter, as it can be irradiated with up to 10⁵ laser shots. The maximum extraction voltage was designed to be 50 kV. We have already finished designing the LIS and we commenced fabrication. We intend to measure the source performance by performing plasma and beam tests up to the end of March 2011.     

Progress with a gas-accepting ion source for Accelerator Mass Spectrometry

The National Ocean Sciences AMS (NOSAMS) facility at Woods Hole Oceanographic Institution has developed a novel, gas-accepting microwave-plasma ion-source. The source is a key component of a compact Accelerator Mass Spectrometry (AMS) system built for the analysis of ¹⁴C in a continuously flowing gas stream. The gas source produces carbon currents from a stream of CO₂ with currents typical of a traditional graphite source. Details of the gas source, including ion current achieved, optimal flow rate, efficiency, and memory are presented. Additionally, data obtained from coupling a gas chromatograph to the source shown. Details about ion optics are presented separately [1].     

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.     

基于CSS的NBI射频离子源控制程序设计

离子源是中性束注入器(Neutral Beam Injector,NBI)的关键子系统之一,根据射频离子源的实验和运行需求,本文设计了一套基于物理实验与工业控制系统(Experimental Physics and Industrial Control System,EPICS)架构的控制程序,实现对射频离子源实验和调试过程的远程监控功能。NBI射频离子源控制程序通过集成开发平台(Control System Studio,CSS)的交互界面开发模块(Best OPI Yet,BOY)实现友好的人机交互界面,使用Jython实现界面逻辑,支持服务器/客户端和EPICS两种通信架构。程序已经上线近半年,实验表明,射频离子源控制程序具备了放电模式设置、时序幅值设置、设备状态实时监控、采集数据实时波形显示等功能,满足了射频离子源实验的远程控制和数据可视化的需求。     

The development of data acquisition and control system for extraction power supply of prototype RF ion source

A 16 kV/20 A power supply was developed for the extraction grid of prototype radio frequency (RF) ion source of neutral beam injector.To acquire the state signals of extraction grid power supply (EGPS) and control the operation of the EGPS,a data acquisition and control system has been developed.This system mainly consists of interlock protection circuit board,photoelectric conversion circuit,optical fibers,industrial compact peripheral component interconnect (CPCI) computer and host computer.The human machine interface of host computer delivers commands and data to program of the CPCI computer,as well as offers a convenient client for setting parameters and displaying EGPS status.The CPCI computer acquires the status of the power supply.The system can turn-off the EGPS quickly when the faults of EGPS occur.The system has been applied to the EGPS of prototype RF ion source.Test results show that the data acquisition and control system for the EGPS can meet the requirements of the operation of prototype RF ion source.     

兰州在线同位素分离器的FEBIAD源研制

叙述了兰州近代物理研究所的在线同位素分离器FEBIAD源的设计原理、 结构、运行状况及离线和在线调试结果。离线测定Kr和Xe的总效率分别为3．1％和4．5％,^129Xe分辨本领达到360,离子源总离子束流小于10μA。在线测到截面为10^-28cm^2、寿命短至1s的反应产物,在线测出^104In总效率达到1.5%-2%,^104Ag和^104Gd达到1％。