title: Carbon beam extraction with 14.5 GHz electron cyclotron resonance ion source at Korea Atomic Energy Research Institute.
abstract: A 14.5 GHz Electron Cyclotron Resonance ion source (ECRIS) has been made to produce C(4+) beam for using a carbon therapy facility and recently tested at KAERI. Highly charged carbon ions have been successfully extracted. When using only CO2 gas, the beam current of C(4+) was almost 14 μA at 15 kV extraction voltage. To get higher current of the C(4+) beam, while optimizing confinement magnetic field configuration (e.g., axial strengths at minimum and extraction side), gas-mixing (CO2/He), and biased disk were introduced. When the gas mixing ratio of the CO2/He gas is 1:8 at an operational pressure of 5 × 10(-7) mbar and the disk was biased to -150 V relative to the ion source body, the highest current of the C(4+) beam was achieved to be 50 μA, more than three times higher than previously observed only with CO2 gas. Some details on the operating conditions of the ECRIS were discussed.
authors.affiliation: Korea Atomic Energy Research Institute, Daejeon 305-353, South Korea.
authors.forename: Cheol Ho
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Korea Atomic Energy Research Institute, Daejeon 305-353, South Korea.
authors.forename: Byung-Hoon
authors.initials: BH
authors.lastname: Oh
authors.affiliation: Korea Atomic Energy Research Institute, Daejeon 305-353, South Korea.
authors.forename: Dae-Sik
authors.initials: DS
authors.lastname: Chang
authors.affiliation: High Energy Accelerator Research Organization, Tsukuba-shi, Japan.
authors.forename: Sun-Chan
authors.initials: SC
authors.lastname: Jeong