Two-Dimensional Proportional Chamber Readout Using Digital Techniques

Two systems of two-dimensional proportional chamber readout are presented, using digital hardware techniques. Centre-of-cluster readout is simple, cheap and very fast: 100 nsec dead-time. Centre-of-gravity readout is slower, with a dead-time of 1 ¿sec, but capable of considerable electronic spatial resolution: 10 ¿m FWHM from 3 mm spaced channels. With this resolution the asymmetry of avalanche formation on anode wires has been observed.