Design and operation of front-end electronics for the HERA-B muon detector

We have implemented a cost-effective design for the readout electronics of both the anode wires and the cathode pads of large area proportional wire chambers for the HERA-B muon system based on the ASD-08 integrated circuit. To control and monitor the large number of readout channels, we have built a distributed control system based on Philips Semiconductors' I/sup 2/C bus and microcontrollers. To date we have installed about 10800 channels of muon chambers and electronics. The average single channel noise occupancy is less than 10/sup -5/, and the detectors have been operated with target interaction rates as high as 70 MHz.