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 per wire 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. To each wire is associated a fast pre-amplifier and a discriminator channel. Global counting rates in excess to 107 events/s are reported. Data acquisition systems are described for 1D (real time) and 2D (off-line) position sensitive detection systems. (author)