A multiwire proportional counter for very high counting rates

Preliminary measurements in a proportional counter with two independently counting wires showed that counting rates up to 10⁶ counts s^-1 wire^-1 can be reached without critical loss in the `true versus measured' linearity relation. Results obtained with a detector containing 30 active wires (2 mm pitch) are presented. With each wire is associated a fast pre-amplifier and a discriminator channel. Global counting rates in excess of 10⁷ events s^-1 are reported. Dead-time losses are corrected by use of simple mathematical-modelling functions. Data-acquisition systems are described for one-dimensional (real-time) and two-dimensional (off-line) position-sensitive detection systems.