DETECTION EFFICIENCY OF THE NEUTRON MODULAR DETECTOR DEMON AND RELATED CHARACTERISTICS

DEMON is a detector array for neutrons emitted in heavy ion induced reactions at low to intermediate energies. The neutron detection efficiency of some single DEMON modules has been measured in the energy range 8-21 MeV, with detection thresholds down to 0.1 MeV equivalent-electron (MeVee). The influence on the efficiency of cross talk, neutron-gamma and neutron-charged particle discrimination techniques was found to be negligibly small. Monte Carlo simulations have been performed and are compared with the experimental data. The relative weight of the interaction channel C-12(n,n'gamma) in the organic liquid scintillator was determined experimentally. Taking into account observed saturation effects in the detector output, a calibration method is proposed for high light outputs, based on the energy loss of cosmic ray muons.