title: On the role of electron energy distribution function in double frequency heating of electron cyclotron resonance ion source plasmas.
abstract: Double frequency heating (DFH) is a tool to improve the output of highly charged ions particularly from modern electron cyclotron resonance ion source installations with very high RF-frequencies. In order to gain information on the DFH-mechanism and on the role of the lower injected frequency we have carried out a series of dedicated experiments where we have put emphasis on the creation of a discrete resonance surface also for this lower frequency. Our well-established method of inserting an emissive MD (metal-dielectric) liner into the plasma chamber of the source is used in these experiments as a tool of investigation. In this way, the electron temperature and density for both ECR zones is increased in a controlled manner, allowing conclusions on the role of the change of the electron-energy-distribution function with and without DFH.
authors.affiliation: National Institute for Physics and Nuclear Engineering, Bucharest, Romania.
authors.forename: L
authors.initials: L
authors.lastname: Schachter
authors.affiliation: Institut für Kernphysik der J. W. Goethe Universität, Frankfurt/Main, Germany.
authors.forename: K E
authors.initials: KE
authors.lastname: Stiebing
authors.affiliation: National Institute for Physics and Nuclear Engineering, Bucharest, Romania.
authors.forename: S
authors.initials: S
authors.lastname: Dobrescu