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采用激光驱动光阴级和100kV直流加速间隙可产生宽度为50~100ps的高亮度脉冲电子束.该装置主要由光阴极制备室和直流加速间隙组成.可以用化学气相沉积、离子注入和离子束增强沉积等方法制备光阴极.通过用EGUN和POISSON程序模拟,给出了直流加速间隙的物理设计.光源采用一台主被动双锁的Nd:YAG激光器,可工作在1064、532和266nm三个波长,重复频率为10Hz.此外,也论述了光阴极制备室与超与腔结合的超导高亮度注入器的有关问题. A DC high brigytness laser driven by photoemissive electron gun is being developed at Peking University,in order to produce 50~100ps electron bunches of high quality.The gun consists of a photocathode preparation chamber and a DC acceleration cavity.Different ways of fabricating photocathode,such as chemical vapor deposition,ion beam implantation and ion beam enhanced deposition,can be adopted.The acceleration gap is designed with the aid of simulation codes EGUN and POISSON,100kV DC high voltage is... 相似文献
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微型电子回旋共振(electron cyclotron resonance, ECR)离子源在紧凑型离子注入机、小型中子管、微型离子推进器等领域有着十分广泛的应用.为了深入认识微型ECR离子源的工作机理,本文以北京大学自主研制的一款微型氘离子源作为研究对象,以氢气和氘气放电形成的等离子体为例,发展了一种基于粒子平衡方程的全局模型.研究结果表明,该离子源束流成分与离子源的运行气压和微波功率有着很强的依赖关系.对于氢气放电等离子体,微波功率低于100 W时,离子源可以分别在低气压和高气压情况下获得离子比超过50%的H~+2离子束和H~+3离子束;当微波功率高于100 W时,可以在很宽的运行气压范围内,获得质子比超过50%的束流.因此,提高微波功率是提高微型离子源质子比的关键.对于氘气放电等离子体, 3种离子比例对运行气压和微波功率的依赖关系与氢气放电等离子体的规律基本一致.但是在相同的运行条件下, D~+比例比H~+比例高10%—25%.也就是说,在微型氘离子源的测试和优化过程中,可以利用氢气代替氘气进行实验,并将质子比测量结果作为相同条件下氘离... 相似文献
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Understanding hydrogen plasma processes based on the diagnostic results of 2.45 GHz ECRIS at Peking University 下载免费PDF全文
Optical emission spectroscopy(OES), as a simple in situ method without disturbing the plasma, has been performed for the plasma diagnosis of a 2.45 GHz permanent magnet electron cyclotron resonance(PMECR) ion source at Peking University(PKU). A spectrum measurement platform has been set up with the quartz-chamber electron cyclotron resonance(ECR) ion source [Patent Number: ZL 201110026605.4] and experiments were carried out recently. The electron temperature and electron density inside the ECR plasma chamber have been measured with the method of line intensity ratio of noble gas. Hydrogen plasma processes inside the discharge chamber are discussed based on the diagnostic results. What is more, the superiority of the method of line intensity ratio of noble gas is indicated with a comparison to line intensity ratio of hydrogen. Details will be presented in this paper. 相似文献
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介绍了SFRFQ加速系统的最新研究进展. 为验证SFRFQ结构的抗打火性能, 设计了一个高功率模型腔, 进行了高功率打火实验, 并最终证明了该结构的可行性. 为验证SFRFQ加速器的载束性能, 设计了一台长度仅为1m的600keV O+ SFRFQ加速器, 它将把从1MeV ISR RFQ引出的O+离子加速到1.6MeV. 为解决1MeV ISR RFQ引出束流与SFRFQ加速器的横向匹配问题, 在其间插入了一个三单元磁四极透镜. SFRFQ加速器加工和1MeV ISR RFQ改造的进展顺利. 相似文献
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A totally home-made 9-cell TESLA type superconducting cavity is mane at Peking University. The cavity abrication is according to DESY specification. The cavity is made of high purity niobium from OTIC, Ningxia. The electron beam welding is carried out at Harbin Institute of Technology, Harbin. By the cooperation, the cavity is tested at Thomas Jefferson National Accelerator Facility, USA. The preliminary result shows the acceleration gradient Eacc is 23 MV/m without quench and has potential for improvement. 相似文献
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Beam dynamics and rf designs of a 104 MHz ladder type IH-RFQ (L-IH-RFQ) accelerator are finished at Peking University for the acceleration of 14C+ from 40 keV to 500 keV. As a specific feature, the output beam energy spread is as low as 0.6% achieved with the internal discrete bunching method, which makes potential applications of RFQ feasible, such as accelerator mass spectrometry and ion implantation. Tolerances of the beam dynamics design are studied by means of changing the input beam parameters, and the results are quite satisfying. On the other hand, the L-IH-RFQ structure is employed, taking advantage of its mechanical stability and the absence of inter-electrode voltage asymmetry. Radio-frequency properties are studied and optimized for reducing power loss with Microwave Studio (MWS). Tuning of the field flatness and frequency is investigated in principle. 相似文献