title: High current H2(+) and H3(+) beam generation by pulsed 2.45 GHz electron cyclotron resonance ion source.
abstract: The permanent magnet 2.45 GHz electron cyclotron resonance ion source at Peking University can produce more than 100 mA hydrogen ion beam working at pulsed mode. For the increasing requirements of cluster ions (H2(+) and H3(+)) in linac and cyclotron, experimental study was carried out to further understand the hydrogen plasma processes in the ion source for the generation of cluster ions. The constituents of extracted beam have been analyzed varying with the pulsed duration from 0.3 ms to 2.0 ms (repetition frequency 100 Hz) at different operation pressure. The fraction of cluster ions dramatically increased when the pulsed duration was lower than 0.6 ms, and more than 20 mA pure H3(+) ions with fraction 43.2% and 40 mA H2(+) ions with fraction 47.7% were obtained when the operation parameters were adequate. The dependence of extracted ion fraction on microwave power was also measured at different pressure as the energy absorbed by plasma will greatly influence electron temperature and electron density then the plasma processes in the ion source. More details will be presented in this paper.
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Shixiang
authors.initials: S
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Ren
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Jia
authors.initials: J
authors.lastname: Chen
authors.affiliation: University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Ailin
authors.initials: A
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Jia'er
authors.initials: J
authors.lastname: Chen