Pulsed operation of a SNICS ion source – ionization efficiency and ion current output

Martin Martschini (Korresp. Autor*in), Petra Holzer, Esad Hrnjic, Alfred Priller, Peter Steier, Robin Golser

Veröffentlichungen: Beitrag in FachzeitschriftArtikelPeer Reviewed

Abstract

Possible ion output enhancement for C−, C4−, Al−, AlO−, CaF3− and SrF3− by pulsed operation of an NEC-MC-SNICS II ion source under AMS-conditions has been investigated. The cathode voltage was switched periodically between −5.0 kV for regular sputtering and an idle value of −0.8 kV. With normal Cs-supply, all investigated species showed a peak ion current in pulsed mode similar to their DC ion current. A study of ionization efficiency of Al− from Al2O3 likewise revealed no enhancement. However, current enhancements of up to 400 % for C− and C4− were observed in pulsed mode when strongly reducing the cesium supply. This is not reflected in ionization efficiency. Under Cs-scarcity, the ionization efficiency of C− in pulsed mode was 12–13 % for samples graphitized with AGE-3. Irrespective of Cs-level, AGE-3 samples and powder mixed samples in DC operation yielded 15–16 % and 16–21 %, respectively. Summarizing, no immediate benefits for AMS could be identified.
OriginalspracheEnglisch
Seiten (von - bis)7-11
Seitenumfang5
FachzeitschriftNuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Jahrgang527
DOIs
PublikationsstatusVeröffentlicht - 15 Sep. 2022

ÖFOS 2012

  • 103014 Kernphysik

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