title: Commissioning of helium injector for coupled radio frequency quadrupole and separated function radio frequency quadrupole accelerator.
abstract: A project to study a new type of acceleration structure has been launched at Peking University, in which a traditional radio frequency quadrupole (RFQ) and a separated function radio frequency quadrupole are coupled in one cavity to accelerate the He+ beam. A helium injector for this project is developed. The injector consists of a 2.45 GHz permanent magnet electron cyclotron resonance ion source and a 1.16 m long low energy beam transport (LEBT). The commissioning of this injector was carried out and an onsite test was held in June 2013. A 14 mA He+ beam with the energy of 30 keV has been delivered to the end of the LEBT, where a diaphragm with the diameter of 7 mm is located. The position of the diaphragm corresponds to the entrance of the RFQ electrodes. The beam emittance and fraction were measured after the 7 mm diaphragm. Its rms emittance is about 0.14 π mm mrad and the fraction of He+ is about 99%.
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Shixiang
authors.initials: S
authors.lastname: Peng
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Jia
authors.initials: J
authors.lastname: Chen
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Ren
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Ailing
authors.initials: A
authors.lastname: Zhang
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Xia
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Shuli
authors.initials: S
authors.lastname: Gao
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Wang
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Luo
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Guo
authors.affiliation: SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Jia'er
authors.initials: J
authors.lastname: Chen