Investigation of the Afterglow Mode with the Caprice ECRIS for the GSI Heavy-Ion-Synchrotron Operation

Tinschert K., Bossler J., Lang R., Schulte H., Spaedtke P.
Gesellschaft fuer Schwerionenforschung mbH, Planckstrasse 1, D-64291 Darmstadt, Germany

Langbein K.
Physikalisch-Technische Beratung, Kraichgaustr. 2, 76698 Ubstadt-Weiher, Germany

The Caprice-type ECRIS of the High Charge State Injector (HLI) of GSI predominantly has been operated in DC mode so far to deliver high duty cycle beams for the experimental area of the LINAC (UNILAC). The increasing demand of the Heavy Ion Synchrotron (SIS) for high intensities of heavy ion beams at very low duty cycle favours the application of the afterglow mode by pulsed operation of the ECRIS in these cases. Experiments with O, Ar, Xe and mainly with Pb were performed at the new ECR injector setup (EIS) which is a copy of the HLI injection beam line. Different RF pulse lengths and repetition rates were compared to optimise the respective afterglow intensities. For Pb two different types of ovens were investigated and modifications of the extraction system were applied. Thus peak intensities in the afterglow for 208Pb27+ of up to 200 emA could be obtained. Stable operation for time periods of several days could be achieved at reduced intensity level. Operational experiences are reported under the aspect of adaptation to SIS injection.

Presenting Author : Tinschert K.
Presentation : Poster
Tuesday Poster Session at 16:00