Electron stripping of Bi ions using a modified 1.4 MeV/u gas stripper with pulsed gas injection

The GSI UNILAC will serve as an injector system for the future Facility for Antiproton and Ion Research (FAIR) facility. To meet the high demands for high-intensity heavy-ion beams, an upgrade of the existing 1.4 MeV/u gas stripper is envisaged with the aim of increasing the stripping efficiency for the required charge state. For this, an increase of the stripping gas density is pursued. Since FAIR will use pulsed beams with a very small duty cycle, a new stripper setup with a pulsed gas injection was implemented to minimize the gas load and thereby enables an increase of the gas pressure. The setup was tested using a bismuth ion beam with a nitrogen gas target. The performance is compared with that of the existing nitrogen gas-jet stripper. The charge stripping of bismuth ions into the same average charge state (26 + ) was achieved.