Beam tests of full-size prototypes of silicon detectors for TOF heavy-ions diagnostics in Super-FRS

The full-size prototypes of large-area silicon detectors for the Time-Of-Flight (TOF) diagnostics of heavy ions were tested with 132Xe (600 MeV/u) beam. The obtained time resolution of the prototypes was about 13 ps, which satisfied the requirements of diagnostics for the Super Fragment Separator (Super-FRS) that is under development at GSI, Darmstadt, Germany. The irradiation effect on the timing properties of silicon detectors was studied with super-fast silicon pad detectors with a rise time of 190 ps. It was shown that the changes in the rise time of the leading edge of the detector current response to 40Ar ions (40.5 MeV/u) were negligible up to the fluence of 2 × 1011 ion/cm2 expected after one year of Super-FRS operation. This result confirms the model of the leading edge current pulse formation via a flow of the polarization current in dense tracks of heavy ions and shows the perspectives for application of silicon detectors for the TOF diagnostics of intensive heavy-ion beams.