title: The role of seed electrons on the plasma breakdown and preglow of electron cyclotron resonance ion source.
abstract: The 14 GHz Electron Cyclotron Resonance Ion Source at University of Jyväskylä, Department of Physics (JYFL) has been operated in pulsed mode in order to study the plasma breakdown and preglow effect. It was observed that the plasma breakdown time and preglow characteristics are affected by seed electrons provided by a continuous low power microwave signal at secondary frequency. Sustaining low density plasma during the off-period of high power microwave pulses at the primary frequency shifts the charge state distribution of the preglow transient toward higher charge states. This could be exploited for applications requiring fast and efficient ionization of radioactive elements as proposed for the Beta Beam project within the EURISOL design study, for example. In this article we present results measured with helium and neon.
authors.affiliation: Department of Physics, University of Jyvaskyla, Jyvaskyla 40500, Finland. olli.tarvainen@jyu.fi
authors.forename: O
authors.initials: O
authors.lastname: Tarvainen
authors.forename: T
authors.initials: T
authors.lastname: Ropponen
authors.forename: T
authors.initials: T
authors.lastname: Thuillier
authors.forename: J
authors.initials: J
authors.lastname: Noland
authors.forename: V
authors.initials: V
authors.lastname: Toivanen
authors.forename: T
authors.initials: T
authors.lastname: Kalvas
authors.forename: H
authors.initials: H
authors.lastname: Koivisto