摘要
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子比例的下限.
Miniature electron cyclotron resonance(ECR)ion sources are widely used in compact ion implanters,miniature neutron tubes,and miniature ion thrusters.To understand the mechanism of miniature ECR ion source,a miniature deuterium ion source developed by Peking University is taken as the research object.In this work,a global model based on particle balance equations is developed for studying the hydrogen plasma and the deuterium plasma inside the miniature ECR source.The research results show that both the hydrogen discharge process and the deuterium discharge process of the ion source are strongly dependent on the gas pressure and microwave power.The calculated results show that high power is beneficial to increasing the proportion of H^(+)(D^(+))ions,low pressure is helpful in augmenting the ratio ofH_(2)^(+)(D_(2)^(+))ions,high pressure and low power are beneficial to enhancing the proportion of H_(3)^(+)(D_(3)^(+))ions.In addition,there is a large difference in ion proportion between hydrogen discharge and deuterium discharge.Under the same operating parameters,the proportion of D+ions is 10%-25% higher than the proportion of H^(+)ions since the plasma density of deuterium discharge is higher than that of hydrogen plasma.Therefore,during the operation of miniature source,H_(2) gas,instead of D_(2) gas,can be used in experiment,and the proportion of D+ions under the corresponding operating parameters can be estimated based on the proportion of H+ions.Finally,the calculated results show that high microwave power is a prerequisite for achieving the high proportion of H^(+)(D^(+))ions.However,owing to the limitation of microwave coupling efficiency,the miniature ECR ion source cannot work when the microwave power is greater than 150 W,so that the H^(+)(D^(+))proportion cannot be further increased,thereby limiting its further applications in neutron sources,implanters,etc.Therefore,how to improve the microwave coupling efficiency has become one of the key research contents of the miniature ECR ion source.The global mo
作者
武文斌
彭士香
张艾霖
周海京
马腾昊
蒋耀湘
李凯
崔步坚
郭之虞
陈佳洱
Wu Wen-Bin;Peng Shi-Xiang;Zhang Ai-Lin;Zhou Hai-Jing;Ma Teng-Hao;Jiang Yao-Xiang;Li Kai;Cui Bu-Jian;Guo Zhi-Yu;Chen Jia-Er(Institute of Applied Physics and Computational Mathematics,Beijing 100094,China;State Key Laboratory of Nuclear Physics and Technology,School of Physics,Peking University,Beijing 100871,China;Department of Modern Physics,University of Science and Technology of China,Hefei 230026,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第14期163-174,共12页
Acta Physica Sinica
基金
国家自然科学基金专项基金(批准号:12147144)
国家自然科学基金(批准号:11775007,11975036)
中国博士后科学基金(批准号:2021M700506)资助的课题.
关键词
电子回旋共振离子源
等离子体模拟
离子比
中子源
electron cyclotron resonance ion source
plasma simulation
ion fraction
neutron source
