High-Density Drift Spaces

Multiwire proportional chambers, with high-density drift spaces attached, have been developed as position-sensitive detectors for non-ionizing radiation. A chamber with a 5 g/cm3 drift space comprising a lead-bismuth converter of 0.8 mm round holes on a 1 mm pitch has been investigated. The detection efficiency is 14% at 0.5 MeV, rising to 18% at 0.66 MeV, with a spatial resolution of 1 mm. Higher efficiencies are possible. These chambers offer new possibilities for photon and neutron detection, and for shower detectors for high-energy particles.