GEANT4 Simulation Studies for Neutron Detection Using GEM Based Gas Detector

Detailed simulation studies using the GEANT4 Simulation tool on the detection of neutrons have been carried out. Based on the guidance through simulation the goal is to carry out an experiment at VECC Kolkata. A mono-energetic neutron beam and neutrons produced from the reactions of alpha and proton beams on the targets of Indium and Tantalum have been used for the studies. It has been planned to use GEM based gaseous detector for the neutron detection. Triple GEM detector consists of drift plane, GEM foils and readout plane. The detector layout of the simulation consists of a converter material (e.g. B10) coated on the inner portion of the drift plane for the conversion of neutrons. The charge particles (e.g. alpha & Li7 for B10) produced in the converter materials create ionization in the drift volume of the GEM detector consisting of a gas mixture of Ar and CO2 (70% Ar, 30% CO2). Neutron detection efficiencies for mono-energetic neutron beams for different converter thicknesses and various threshold cuts (energy deposition value) will be reported. Neutron yields for the setup involving alpha and proton beams have been studied for different target thickness. The gammas produced in these reactions are rejected using lead sheets alongwith threshold cuts on energy deposition. The systematic studies of the variation of yields involving several beam-target combinations and detector-converter configurations have been studied.