title: Recent development of RIKEN 28 GHz superconducting electron cyclotron resonance ion source.
abstract: Over the past two years, we have tried to improve the performance of the RIKEN superconducting electron cyclotron resonance ion source using several methods. For the production of U vapor, we chose the sputtering method because it is possible to install a large amount of material inside the plasma chamber and thus achieve long-term operation without a break, although it is assumed that the beam intensity is weaker than in the oven technique. We also used an aluminum chamber instead of a stainless steel one. Using these methods, we successfully produced ∼180 eμA of U(35+) and ∼230 eμA of U(33+) at the injected radio frequency (RF) power of ∼4 kW (28 GHz). Very recently, to further increase the beam intensity of U(35+), we have started to develop a high temperature oven and have successfully produced a highly charged U ion beam. In this contribution, we report on the beam intensity of highly charged U ions as a function of various parameters (RF power and sputtering voltage) and discuss the effects of these parameters on the beam stability in detail.
authors.affiliation: RIKEN, 2-1 Hirosawa, Wako, Saitama, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Higurashi
authors.affiliation: RIKEN, 2-1 Hirosawa, Wako, Saitama, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Ohnishi
authors.affiliation: RIKEN, 2-1 Hirosawa, Wako, Saitama, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ozeki
authors.affiliation: RIKEN, 2-1 Hirosawa, Wako, Saitama, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kidera
authors.affiliation: RIKEN, 2-1 Hirosawa, Wako, Saitama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakagawa