title: The effect of gas mixing and biased disc voltage on the preglow transient of electron cyclotron resonance ion source.
abstract: The effect of gas mixing and biased disc voltage on the preglow of electron cyclotron resonance ion source plasma has been studied with the AECR-U type 14 GHz ion source. It was found that gas mixing has a significant effect on the preglow. The extracted transient beam currents and efficiency of the heavier species increase, while the currents and efficiency of the lighter species decrease when gas mixing is applied. The effect of the biased disc was found to be pronounced in continuous operation mode in comparison to preglow. The data provide information on the time scales of the plasma processes explaining the effects of gas mixing and biased disc. The results also have implications on production of radioactive ion beams in preglow mode for the proposed Beta Beam neutrino factory.
authors.affiliation: Department of Physics, University of Jyväskylä, Jyväskylä 40500, Finland. olli.tarvainen@jyu.fi
authors.forename: O
authors.initials: O
authors.lastname: Tarvainen
authors.forename: V
authors.initials: V
authors.lastname: Toivanen
authors.forename: J
authors.initials: J
authors.lastname: Komppula
authors.forename: T
authors.initials: T
authors.lastname: Kalvas
authors.forename: H
authors.initials: H
authors.lastname: Koivisto