A digital readout system for the SYRMEP silicon strip detectors

The SYRMEP project (SYnchrotron Radiation for MEdical Physics) intends to improve mammography performances using two non-traditional means: synchrotron radiation and silicon detectors. A silicon crystal (the monochromator) allows to choose the optimal beam energy that leads to the maximum signal to noise ratio, while the detectors are arranged to form a matrix of pixels and coupled to low noise high-gain VLSI integrated circuits making the single photon counting technique possible. We present the data acquisition system implemented to read out the VLSI circuit with particular emphasis on two dedicated CAMAC modules that generate the control signals and store the chip digital output on memories that can be accessed via the CAMAC bus. It has been useful in testing the chip performances and can be considered a prototype of the final SYRMEP data acquisition system.