Design and operation of a fast high-granularity silicon detector system in a high-radiation environment

We have designed, realized and operated a fast silicon detector system (50 MHz sampling frequency) to measure the angular distribution and the multiplicity of charged secondaries produced in high-energy Pb–Pb interactions, within the NA50 experiment. We present here the detector design, discuss some of the problems faced during the commissioning and report on the first results on the operation of the full system. In particular, the questions related to the operation of an integrated high-speed binary readout in a high-radiation environment (10^14 particles/cm^2 and about 10 Mrads) and to the radiation effects on the system during the run will be addressed.