Charge collection efficiency of an irradiated cryogenic double-p silicon detector

Abstract

We present results on the measurement of the charge collection efficiency of a p +/n/p + silicon detector irradiated to 1×10 15 n/cm 2, operated in the temperature range between 80 and 200 K. For comparison, measurements obtained with a standard silicon diode (p +/n/n +), irradiated to the same fluence, are also presented. Both detectors show a dramatic increase of the CCE when operated at temperatures around 130 K. The double-p detector shows a higher CCE regardless of the applied bias and temperature, besides being symmetric with respect to the polarity of the bias voltage. At 130 K and 500 V applied bias the double-p detector shows a CCE of 80%, an unprecedented result for a silicon detector irradiated to such a high dose.