Design, manufacturing and calibration of the new models of Silver GM activation counters

Abstract The innovative single and array models of silver Geiger Muller (GM) activation counters were designed to measure the fast neutron fluence. These counters were made of inner and outer neutron moderators (PE) sections with special designs of silver foil and thin wall GM counter. The Monte Carlo N-Particles MCNPX2.6 code was used to simulate the optimum dimension and energy responses of these counters. The two counters were calibrated by means of 241Am-Be radioisotopic neutron source with 16Ci activity. The detection efficiencies of single and array counters were 0.07±0.005 and 0.785±0.05, respectively. The energy responses of these two counters were determined to be flat for low energy neutrons of 2keV to 1MeV which were rarely observed in other neutron detectors. The directional sensitivities were also improved after rejecting scattered neutrons by surrounding materials which will be of high importance for intense pulsed neutron sources.