The Simulation on Two-dimensional position sensitive scintillation neutron detector

Chinese Spallation Neutron Source(CSNS) project has started since October 2011, As substitute of ³He gas detector, scintillator neutron detector has been a research focus internationally. In this paper, a module of position sensitive neutron detector based on ⁶LiF/ZnS(Ag) scintillator was constructed by GEANT4 package, and its key properties were studied. The simulation results show that the thermal neutron detection efficiency could reach 49.1% when 'sandwich structure' of detector was set. Both simulation and experimental result reveal its good ability of n/γ rejection ration, and the gamma sensitive could be less than 10^-5. The smaller of the distance between each WLSF, and the gap between the WLSFs array and scintillator are, the better the position resolution is. The intrinsic spatial resolution is 0.08 mm for X-axis and 0.12 mm for Y-axis. The simulation results and that of parts experimental results plot the detector have a good 2D imaging capability. Work above can provide reliable data for scintillation neutron detector in CSNS. (authors)