Efficiency and noise measurements of non-uniformly irradiated double-sided silicon strip detectors

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