Two-dimensional thermal neutron detector

A two-dimensional thermal neutron detector for neutron diffraction experiments has been developed and designed at the St. Petersburg Nuclear Physics Institute, Russian Academy of Sciences. The detector is based on a multiwire proportional chamber with cathode-strip delay line readout. The detector aperture is 170 × 300 mm2 and the anode wire spacing is 4 mm. The chamber is filled with a 1.5 atm 3He + 2 atm CF4 gas mixture. To conserve high purity of the gas mixture, all electrodes are made of quartz glass. The spatial resolution of the detector is 2.5 mm and the detection efficiency is 60% for 9 A neutrons.