First OTR Beam Time at X2 (Oct. 2011)

OTR (Optical Transition Radiation) is widely used for profile measurements of elecron beams. Since there are no experiences at GSI for OTR measurements with heavy ions, an experiment was set up in the experimental area X2 for the first prove of principle and for validation of expected denpedencies as estimated by A. Lumpkin.

The uranium ions delivered from the UNILAC have an energy of 11.4 MeV/u and a charge state of 28+. Stripping foils on a drive (carbon: 370 µg/cm² ; 571 µg/cm² ; 563 µg/cm²) are used to achieve charge states of ~73+ (without charge separation).

With CCD & IICCD cameras the beam spot on the OTR target was observed for U28+ and U73+. Different stripping foils and OTR target materials were tested as well as the observable light yield for different beam currents. Additionally, spectroscopic investigations were performed.