A latest developed all permanent magnet ECRIS for atomic physics research at IMP

Electron cyclotron resonance (ECR) ion sources have been used for atomic physics research for a long time. With the development of atomic physics research in the Institute of Modern Physics (IMP), additional high performance experimental facilities are required. A 300 kV high voltage (HV) platform has been under construction since 2003, and an all permanent magnet ECR ion source is supposed to be put on the platform. Lanzhou all permanent magnet ECR ion source No. 2 (LAPECR2) is a latest developed all permanent magnet ECRIS. It is a 900 kg weight and circle divide 650 mm X 562 mm outer dimension (magnetic body) ion source. The injection magnetic field of the source is 1.28 T and the extraction magnetic field is 1.07 T. This source is designed to be running at 14.5 GHz. The high magnetic field inside the plasma chamber enables the source to give good performances at 14.5 GHz. LAPECR2 source is now under commissioning in IMP. In this article, the typical parameters of the source LAPECR2 are listed, and the typical results of the preliminary commissioning are presented.

基于ECRIS的等电荷态序列离子与氦、氖、氩碰撞反应中的多电子过程研究

本工作设计并建立了一个离子-原子碰撞实验终端。该终端具有一定的通用性，可用于我所EcRIS、ECRIS一300kV高压平台和兰州大学Zxl．7MV串列加速器。终端的设计特别考虑了气体靶实验中系统的动态真空和对高品质弱束流流强的控制。2004年7月-10月，利用我所ECRIS提供的束流，在该终端上进行了首轮实验。本工作指出，除了入射离子的电荷态和速度外，其空能级结构是碰撞反应的另一个主导因素，并在此基础上提出了等电荷态序列离子的概念。为了确定离子空能级结构对碰撞反应的影响，本工作系统研究了等速度的q＝6序列离子（C6＋、N6＋、。6＋、F6＋、Ne6＋、Ar6＋、co6＋）、q＝7序列离子（07＋、F7＋、Ne7＋、57＋、Ar7＋）、q＝8序列离子（FS＋、Nes＋、Ars＋、cos＋）、q：9序列离子（Fg＋、Neg＋、519＋、59＋、Arg＋、cag＋）和叮：11序列离子（Si1、Aill＋、Call＋）与氦、氖、氢的碰撞反应。实验证实，对于等速度、等电荷态序列离子，碰撞反应与离子种类强烈相关。利用同位素纯的13coZ作为EcRIs的工作气体，获得了纯净的全裸离子13C6＋束流，研究了13C6＋离子与氦、氖、氢碰撞反应与碰撞速度的关系。实验发现，在C6十一He的碰撞反应中，纯双电子俘获（DC）与双电子转移（DE）截面比JDcDIZ随碰撞速度的增加而明显下降，这暗示准分子俄歇机制在本能区C6＋一He碰撞反应中的贡献不可忽略。用MCBM描述离子-原子相互作用阶段，用电子蒸发模型统一处理碰撞后多电了激发态散射离子和反冲离子的衰变，作者编写了计算程序COBEEM。经典过垒模型（如ECBM和MCBM）仅用电荷态q一个参数描述入射离子，本工作实验证实了这种描述是不完备的。COBEEM程序对此问题进行了初步修正。该程序还包含了ECBM和Selberg等人提出了经验公式的计算。

兰州重离子加速器的状态和发展

文章首先简要地介绍了世界上重离子加速器的发展状态 .然后对兰州重离子加速器 (HIRFL)的结构、建造过程、运行情况、多年来以及目前正在进行的主要改造项目进行了描述 .为适应核物理及其相关学科的持续发展研究的需要 ,对HIRFL近期和将来的发展情况作了概括的描述 .

36-segmented high magnetic field hexapole magnets for electron cyclotron resonance ion source

Two high magnetic field hexapoles for electron cyclotron resonance ion source (ECRIS) have successfully fabricated to provide sufficient radial magnetic confinement to the ECR plasma. The highest magnetic field at the inner pole tip of one of the magnets exceeds 1.5 T, with the inner diameter (i.d.)=74 mm. The other hexapole magnet provides more than 1.35 T magnetic field at the inner pole tip, and the i.d. is 84 mm. In this article, we discuss the necessity to have a good radial magnetic field confinement and the importance of a Halbach hexapole to a high performance ECRIS. The way to design a high magnetic field Halbach structure hexapole and one possible solution to the self-demagnetization problem are both discussed. Based on the above discussions, two high magnetic field hexapoles have been fabricated to be utilized on two high performance ECRISs in Lanzhou. The preliminary results obtained from the two ECR ion sources are given

A high charge state all-permanent magnet ECR ion source for the IMP 320 kV HV platform

A 320 kV high voltage (HV) platform has been constructed at Institute of Modern Physics (IMP) to satisfy the increasing requirements of experimental studies in some heavy ion associated directions. A high charge state all-permanent magnet ECRIS-LAPECR2 has been designed and fabricated to provide intense multiple charge state ion beams (such as 1000 e mu A O6+, 16.7 e mu A Ar14+, 24 e mu A Xe27+, etc.) for the HV platform. LAPECR2 has a dimension of 0 650 mm x 560 mm. The powerful 3D magnetic confinement to the ECR plasma and the optimum designed magnetic field for the operation at 14.5 GHz makes it possible to obtain very good performances from this source. After a brief introduction of the ECRIS and accelerator development at IMP, the conceptual design of LAPECR2 source is presented. The first test results of this all-permanent magnet ECRIS are given in this paper.

Commissioning test of LAPECR2 source on the 320kV HV platform

The high charge state all permanent Electron Cyclotron Resonance Ion Source (ECRIS) LAPECR2 (Lanzhou All Permanent magnet ECR ion source No.2) has been successfully put on the 320kV HV platform at IMP and also has been connected with the successive LEBT system. This source is the largest and heaviest all permanent magnet ECRIS in the world. The maximum mirror field is 1.28T (without iron plug) and the effective plasma chamber volume is as large as circle divide 67mm x 255mm. It was designed to be operated at 14.5GHz and aimed to produce medium charge state and high charge state gaseous and also metallic ion beams. The source has already successfully delivered some intense gaseous ion beams to successive experimental terminals. This paper will give a brief overview of the basic features of this permanent magnet ECRIS. Then commissioning results of this source on the platform, the design of the extraction system together with the successive LEBT system will be presented.

Lanzhou all permanent ECR ion source No.1 - LAPECR1

The Lanzhou All Permanent magnet ECR ion source NO. 1 (LAPECR1) is the first all permanent magnet multiple ECRIS made in IMP. This ECRIS is running at 14.5GHz and can provide intense low charge state ion beams (varying from several to hundreds of e mu A) or medium charge state ion beams (varying from several to tens of e mu A). The size of source body is circle divide 102mmx296mm, the compactness and economical features enable the source suitable to be put on a HV platform or equipped by a small laboratory. This article gives the main parameters of the ion source.

Production of highly charged ion beams with SECRAL

Superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is an all-superconducting-magnet electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged ion beams to meet the requirements of the Heavy Ion Research Facility in Lanzhou (HIRFL). To further enhance the performance of SECRAL, an aluminum chamber has been installed inside a 1.5 mm thick Ta liner used for the reduction of x-ray irradiation at the high voltage insulator. With double-frequency (18+14.5 GHz) heating and at maximum total microwave power of 2.0 kW, SECRAL has successfully produced quite a few very highly charged Xe ion beams, such as 10 e mu A of Xe37+, 1 e mu A of Xe43+, and 0.16 e mu A of Ne-like Xe44+. To further explore the capability of the SECRAL in the production of highly charged heavy metal ion beams, a first test run on bismuth has been carried out recently. The main goal is to produce an intense Bi31+ beam for HIRFL accelerator and to have a feel how well the SECRAL can do in the production of very highly charged Bi beams. During the test, though at microwave power less than 3 kW, more than 150 e mu A of Bi31+, 22 e mu A of Bi41+, and 1.5 e mu A of Bi50+ have been produced. All of these results have again demonstrated the great capability of the SECRAL source. This article will present the detailed results and brief discussions to the production of highly charged ion beams with SECRAL.

低速高电荷态离子与微孔箔的相互作用研究

低速高电荷态离子与纳米微孔箔相互作用的研究无论在基础研究方面还是实际应用方面都扮演着重要的角色，因此在近年来受到了广泛的关注，成为一个研究热点。 论文介绍了在兰州重离子加速器国家实验室320kV高压电子回旋共振离子源（ECRIS）上新建成的表面物理实验终端；着重叙述了在该终端上开展的高电荷态离子与绝缘体纳米微孔箔相互作用的实验工作，包括高电荷态离子穿过微孔箔后的电荷态分布、角分布以及微孔箔的导向能力；系统的研究和讨论了（1）出射离子的电荷态分布；（2）出射离子产额的角度分布，具体内容有入射倾角、入射离子的动能、电荷态以及后表面带电对角度分布的半高宽度的影响；（3）微孔箔导向能力，具体内容有表征导向能力的临界角、入射离子的动能、电荷态的变化以及后表面带电对临界角的影响；（4）总的离子产额随入射离子束流强的变化情况。 实验结果表明，微孔箔对入射的低速高电荷态离子有明显的导向作用，出射离子的角度分布为对称分布，且超过97%的出射离子保持了入射时的电荷态；入射倾角、初始动能、初始电荷态以及微孔箔后表面带电与否等对离子产额角度分布的半高宽和临界角会产生影响；总的离子产额会随入射流强的变化出现拐点。论文还利用导向效应模型对实验中出现的各种现象进行了定性的解释，并对进一步深入研究该项课题提出了初步的设想