title: Experimental results of superimposing 9.9 GHz extraordinary mode microwaves on 2.45 GHz ECRIS plasma.
abstract: Efficient production of multicharged ions has been investigated on the tandem-type ECRIS in Osaka University. According to the consideration of the accessibility conditions of microwaves to resonance and cutoff regions, it was suggested that the upper hybrid resonance (UHR) heating contributed to enhancement of ion beam intensity. In order to enhance multicharged ion beams efficiently, injecting higher frequency microwave with extraordinary (X-mode) toward UHR region has been tried. In this study, 2.45 GHz frequency microwaves are used for conventional ECR discharge, and 9.9 GHz frequency microwaves with X-mode are superimposed for UHR heating. The effects of additive microwave injection are investigated experimentally in terms of plasma parameters and electron energy distribution function (EEDF) measured by Langmuir probe and ion beam current. As the results show, it is confirmed that the electrons in the high energy region are affected by 9.9 GHz X-mode microwave injection from the detailed analysis of EEDF.
authors.affiliation: Division of Electrical, Electronic, and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Nishiokada
authors.affiliation: Division of Electrical, Electronic, and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Nagaya
authors.affiliation: Division of Electrical, Electronic, and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Hagino
authors.affiliation: Division of Electrical, Electronic, and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Takuro
authors.initials: T
authors.lastname: Otsuka
authors.affiliation: National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-855, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Muramatsu
authors.affiliation: Division of Electrical, Electronic, and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Fuminobu
authors.initials: F
authors.lastname: Sato
authors.affiliation: National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-855, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kitagawa
authors.affiliation: Division of Electrical, Electronic, and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Yushi
authors.initials: Y
authors.lastname: Kato
mesh_terms: D008872:Microwaves; D058626:Plasma Gases
chemical_list: D058626:Plasma Gases