Large area thin film semiconductor detectors using multichannel counting Castor readout chip

The performance of charged particle counters associating thin diamond or amorphous silicon (a-Si) detectors to Castor VLSI analog-digital circuits for the fabrication of large area detectors an reported. The 20 /spl mu/m thick semiconductor detectors were synthesised using chemical vapour deposition (CVD) technique. Detectors of 2.5/spl times/2.5 cm/sup 2/ area were segmented in 32 sub-areas of 13 mm/sup 2/ in order to limit the electronic noise per reading channel. The 32 channel circuit was used to record the counting rate and the total number of counts on each segment. Such detection systems were tested under alpha particles (/sup 241/Am) as well as under low energy beta particles (/sup 14/C). The results show that large area detection systems can readily be fabricated at low cost by the association of an application specific readout chip (ASIC) with chemically vapour deposited semiconductor detectors.