title: Measurements and effects of backstreaming ions produced at bremsstrahlung converter target in Dragon-I linear induction accelerator.
abstract: Positive ions released from x-ray converter target impacted by electron beam of millimeter spot size can be trapped and accelerated in the incident beam's potential well. As the ions move upstream, the beam will be pinched first and then defocused at the target. Four Faraday cups are used to collect backstreaming ions produced at the bremsstrahlung converter target in Dragon-I linear induction accelerator (LIA). Experimental and theoretical results show that the backstreaming positive ions density and velocity are about 10(21)/m(3) and 2-3 mm/micros, respectively. The theoretical and experimental results of electron beam envelope with ions and without ions are also presented. The discussions show that the backstreaming positive ions will not affect the electron beam focusing and envelope radius in Dragon-I LIA.
authors.affiliation: Institute of Fluid Physics, CAEP, Mianyang, Sichuan 621900, China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Yu
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.forename: Nan
authors.initials: N
authors.lastname: Chen
authors.forename: Yutong
authors.initials: Y
authors.lastname: Xie
authors.forename: Xiaoguo
authors.initials: X
authors.lastname: Jiang
authors.forename: Cheng
authors.initials: C
authors.lastname: Jian