Wire proportional chambers in an intensive particle beam

A system including six wire proportional chambers is described. The system is used to measure the coordinates of particles in the πsub(--)meson beam with an intensity up to 3x106 particles per second at a loading of 0.5x106 particles/s per wire. Proportional chambers are made as two units, each consisting of three coordinate planes. The wires in two planes are mutually perpendicular, the third one being turned through 45 deg. To reconstruct the beam particle trajectory, it is sufficient to have data from two planes. The additional coordinate allows to reduce significantly the unit inefficiency due to calculation errors and to identify definitely such events when during the resolution time of the chambers two particles pass through them. All chambers have circular electrodes. Each chamber contains 64 signal wires 20 mkm in dia made of gilded tungsten wound up with a pitch of 2 mm. The chamber gap is equal to 6 mm. The chamber electronics is described. The data obtained are processed using a computer operating on-line with measuring instruments. The operating experience with the system of wire proportional chambers described has shown the system to provide an efficient recording of particle coordinates in beams with an intensity of 3x106 particles/s, when choosing thoroughly the chamber operating conditions, applying fast electronics and using additional chambers