Efficiency of non-uniformly irradiated double-sided silicon strip detectors

We have investigated the efficiency and the noise occupancy of a double-sided silicon strip detector, which was subjected to non-uniform proton irradiations up to a maximum equivalent fluence of 5/spl middot/10/sup 13/p/spl middot/cm/sup -2/. The depletion voltage, varying over time due to controlled annealing, was close to zero on one end of the 6 cm strips and 190 V at the high radiation end. We have determined the efficiency and noise occupancy on both n-side and p-side in a /sup 106/RU telescope, using a binary read-out system with 22 ns shaping time. The n-side exhibits superior performance after type inversion.