title: Note: Enhanced production of He⁺ from the Versatile Ion Source (VIS) in off-resonance configuration.
abstract: The Versatile Ion Source (VIS) is a microwave discharge ion source installed at INFN-LNS and here used as test-bench for the production of high intensity low emittance proton beams and for studies on plasma physics. A series of measurements have been carried out with VIS in order to test the source with light ions. In particular a He(+) beam has been characterized in terms of plasma discharge parameters. The experiment has been triggered by the observation of X-radiation emission from the plasma for some configuration of the magnetic field profile. The plasma electron energy distribution function is in fact modified when in some regions of the plasma chamber under-resonance discharge takes place, fulfilling the condition that allows the electromagnetic wave to electrostatic wave conversion. These tests allowed obtaining more than 50 mA of He(+) beams.
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Castro
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Mascali
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Celona
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Gammino
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Caliri
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Di Bartolo
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Lanaia
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Mazzaglia
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Miracoli
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Neri
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Torrisi
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Altana
authors.affiliation: INFN-Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Ciavola