title: Upgrade of the extraction system of permanent magnet electron cyclotron resonance ion source.
abstract: A set of new ion extraction electrodes have been designed for the permanent magnetic electron cyclotron resonance ion source at Peking University to improve beam quality and transmission. PBGUNS has been used to optimize the extraction electrodes and simulate the beam behavior at the extraction region. The experiments showed that with the new system, the beam half divergence angle can be less than 40 mrad and the normalized rms emittance is about 0.13pi mm mrad when the extracted current is 100 mA at 50 keV in pulse mode. The voltage of the suppression electrode has great effect on beam divergence. The effect of the microwave power and gas flow is also studied.
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: M
authors.initials: M
authors.lastname: Zhang
authors.forename: S X
authors.initials: SX
authors.lastname: Peng
authors.forename: H T
authors.initials: HT
authors.lastname: Ren
authors.forename: Z Z
authors.initials: ZZ
authors.lastname: Song
authors.forename: Z X
authors.initials: ZX
authors.lastname: Yuan
authors.forename: Q F
authors.initials: QF
authors.lastname: Zhou
authors.forename: P N
authors.initials: PN
authors.lastname: Lu
authors.forename: R
authors.initials: R
authors.lastname: Xu
authors.forename: J
authors.initials: J
authors.lastname: Zhao
authors.forename: J X
authors.initials: JX
authors.lastname: Yu
authors.forename: J E
authors.initials: JE
authors.lastname: Chen
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Guo
authors.forename: Y R
authors.initials: YR
authors.lastname: Lu