Kato Yushi, Nishiokada Takuya, Hamada Kouta, Onishi Koji, Takeda Tatsuto, Okumura Kazuki, Omori Takayuki, Kubo Wataru, Ishihara Masaki, Harisaki Shuhei
Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
Rev Sci Instrum. 2020 Jan 1;91(1):013315. doi: 10.1063/1.5127315.
We have considered the accessibility condition of electromagnetic and electrostatic waves propagating in an electron cyclotron resonance (ECR) ion source (ECRIS) plasma and then investigated experimentally their correspondence relationships with production of multicharged ions. It has been clarified that there exists an efficient configuration of ECR zones for producing multicharged ion beams and has been suggested that a new resonance, i.e., upper hybrid resonance (UHR), must have occurred. We have been trying to perform advanced experiments with 4-6 GHz X-mode microwaves to the 2.45 GHz ECRIS plasma, and we have succeeded in enhancing the production of multicharged ions by launching X-mode microwaves of these bands. Furthermore, at the same time, we have observed sharp increases in electron energy distribution functions in the ECRIS plasma by means of probe methods. It has been concluded that the UHRs must have occurred when applying multiplex microwaves with their frequencies away from those frequencies for ECR in the ECRIS. In this paper, we will describe in brief the theoretical background and the results of these new experiments.
我们考虑了在电子回旋共振（ECR）离子源（ECRIS）等离子体中传播的电磁波和静电波的可及性条件，然后通过实验研究了它们与多电荷离子产生的对应关系。已经阐明，存在一种用于产生多电荷离子束的ECR区的有效配置，并且有人提出一定发生了一种新的共振，即上混合共振（UHR）。我们一直在尝试对2.45GHz的ECRIS等离子体施加4 - 6GHz的X模微波进行先进实验，并且通过发射这些频段的X模微波成功提高了多电荷离子的产生。此外，与此同时，我们通过探针方法观察到ECRIS等离子体中电子能量分布函数急剧增加。可以得出结论，当在ECRIS中施加频率偏离ECR频率的多重微波时，必定发生了UHR。在本文中，我们将简要描述这些新实验的理论背景和结果。
