The digital data acquisition chain and the cosmic ray trigger system for the SLD Warm Iron Calorimeter
The entire data-acquisition chain, from the custom-made front-end electronics to the Fastbus readout and data-reduction module, for the digital readout of the SLD limited streamer tube Warm Iron Calorimeter and Muon Identifier is described. Also described is a Fastbus Cosmic Logic Unit being developed to achieve the capability of reading cosmic ray events, also during the inter-crossing time, for apparatus monitoring and calibration purposes. 9 refs., 9 figs.
A FASTBUS digital readout module for streamer tubes
A FASTBUS module has been designed for the acquisition and preliminary elaboration of digital data coming from limited streamer-tube strip readout electronics. The module is based on the Motorola MC68020 microprocessor and will perform fast readout with zero suppression, cluster searching, and apparatus monitoring on calorimeter cathode strip data. A description is given of the readout system architecture, the front-end processor, and the FASTBUS interface. >
rPET detectors design and data processing
Small animal PET systems based on rotating planar detectors posses some interesting advantages for high sensitivity, high resolution imaging. We have designed the rPET detectors based on MLS crystals assembled on a 30times30 matrix optically coupled to a flat-panel PS-PMT. Weighted position readout circuits pre-process the 64 signals from the 8times8 anodes matrix, which are digitized using a charge-integrating converter. The amplification electronics, including the trigger output for coincidence detection, and the high voltage supply are integrated in a three PCBs stack that forms the base attached to the back of the PMT. The whole assembly is enclosed in a light tight, lead (Pb) shielded aluminum box. The detectors are mounted on a rotating gantry with more than 180 degrees rotation span. The digitized events are screened and histogramed, and a modified center of gravity algorithm removes from the position calculation those signals with poor signal to noise ratio. Apparent mean crystal size on the 511 keV field-flood images is 0.6 mm, mean peak-to-valley ratio is better than 8, and intrinsic resolution is 1.5 mm at the central row, with the energy window wide open. Sensitivity (CPS) for a pair of these detectors set in coincidence at 160 mm distance is 1%