High intensity operation of multiwire proportional chambers

Abstract We report on a system of 17 multiwire proportional chambers operated in a 28.5 GeV/ c proton beam with intensities up to 10 6 particles/s for a total integrated intensity of 10 12 protons. Data for both low (∼10 4 protons/s) and high intensity beams are presented; no variation of efficiency was seen as a function of instantaneous integrated intensity; some variation was seen in the frequency of double firing. Results are also presented on the dependence of firing multiplicity on angle of incidence and on track ionization (up to 7 times minimum).