Effects of irradiation of energetic heavy ions on digital pulse shape analysis with silicon detectors

The next generation of 4p detector arrays for heavy ion studies will largely use Pulse Shape Analysis to push the performance of silicon detectors with respect to ion identification. Energy resolution and pulse shape identification capabilities of silicon detectors under prolonged irradiation by energetic heavy ions have thus become a major issue. In this framework, we have studied the effects of irradiation by energetic heavy ions on the response of neutron transmutation doped (nTD) silicon detectors. Sizeable effects on the amplitude and the rise time of the charge signal have been found for detectors irradiated with large fluences of stopped heavy ions, while much weaker effects were observed by punching-through ions. The robustness of ion identification based on digital pulse shapet echniques has been evaluated.