Radiation damage test of silicon microstrip detectors

Radiation damage tests of newly developed silicon microstrip detectors were performed using 800 GeV proton beam. The leakage current increased proportional to the integrated beam intensity. No fatal damages such as breakdown are observed up to the integrated intensity exceeding 1014cm2. The peak of minimum ionizing particles is clearly seen for irradiated silicon detectors with leak current of as high as 1.4 μAstrip. There is no pulse height degradation. The bias voltage necessary for full depletion had to be raised from 20 V to 40 V for radiation damaged samples. The authors observed a strong temperature dependence of leak current caused by the radiation damage. It is demonstrated that by cooling the detector to 70C, they are able to reduce the leak current by factor 4. They demonstrated that the silicon detector could be made operational by moderate cooling even after irradiation much higher than 1014cm2