An overall MWPC-readout system based on chamber mounted ASIC´s

At the Julich Cooler Synchrotron COSY the magnetic spectrometer ANKE (Apparatus for Studies of Nucleon and Kaon Ejectils) is installed. Reaction products emitted by an internal target in forward direction are measured. About 11,000 channels must be read out. This justified the design of a VLSI based readout system. For this, an analog chip (RAL 118)-a low power high speed eight channel amplifier and discriminator-is foreseen. Digital delay, zero suppression and address encoding are done by the digital chip RAL 111 from the Rutherford Laboratory. A scalable and flexible array of chamber mounted front end boards may be extended to instrument detectors of any size. Readout is performed by serializing hit addresses over a high speed optical link to a CAMAC readout module which serves for additional data reduction, subevent building and a number of test functions. Furthermore, subevent data is transferred over a front panel ECLbus (FERAbus*) to a crate controller with PCI-interface. An industrial PC with diskless UNlX-compatible operating system (NetBSD) controls the CAMAC crate, processes the event data and offers a connection to a central event builder