• P. Gerhard, W.A. Barth, L.A. Dahl, A. Orzhekhovskaya, K. Tinschert, W. Vinzenz, H. Vormann, S.G. Yaramyshev
  GSI, Darmstadt
• A. Schempp, M. Vossberg
  IAP, Frankfurt am Main

The super heavy element research is one of the outstanding projects at GSI. At SHIP* six new elements have been discovered; moreover, nuclear chemical experiments with transactinides were recently performed at TASCA**. This experimental program strongly benefits from high average beam intensities. In the past beam currents were raised significantly by a number of improvements. The present upgrade program comprises the installation of a superconducting (sc) 28 GHz ECR ion source, a new frontend (low energy beam transport and RFQ), and, in the long term, an sc cw Linac. For the short term, the new RFQ will raise the duty factor by a factor of two (50%), limited by the following accelerator only. This bottleneck will be resolved by the applied cw Linac. Beam tests with a newly developed sc CH cavity are scheduled for 2012. The setup of the RFQ as the major upgrade of the 20 year old HLI*** is in progress, the commissioning will be finished in March 2010. Besides a higher duty factor, improved longitudinal beam quality and transmission are expected. This paper reports on the challenging rf and beam commissioning.

* Separator for Heavy Ion Reaction Products
** TransActinide Separator and Chemistry Apparatus
*** High charge state injector, a part the UNILAC

• P. Spädtke, R. Lang, J. Mäder, F. Maimone, J. Roßbach, K. Tinschert
  GSI, Darmstadt
• J.W. Stetson
  NSCL, East Lansing, Michigan

Electron Cyclotron Resonance Ion Sources (ECRIS) are increasingly used as ion source for different types of accelerator because of their high current densities for highly charged ions. To investigate the ion beam quality, normally delivered to the RFQ of the high charge state injector at GSI, we had the chance to install a viewing target close to the position of ion beam injection into the RFQ. The profile visible on the viewing target could be recorded through a regular glass window by a simple camera outside the vacuum. The RFQ itself has been removed for these measurements. We have found a highly structured ion beam distribution at that position. These structures, already caused by the hexapolar field within the ion source have already been observed directly behind the extraction. They are transported through the beam line without becoming homogeneous, which indicates a high degree of space charge compensation for that cw-beam. If the full beam line is mastered by the dipole, all charge states show similar ion beam distribution on the target for a given extraction voltage. This is also a hint, that the structures have been produced within the source already.