Point spread function of neutron pinhole imaging in high gamma ray background

The ratios of good event, energy deposition of gamma and neutron with different offsets are obtained by the model of pinhole imaging based on Geant4 system. The effect on the point spread function(PSF) of neutron pinhole imaging caused by the high gamma ray background is simulated and analyzed. The results show that with the offsets less than 1 cm the ratios of good event, peak value of energy deposition, total energy deposition of gamma and neutron are 0.40~0.42, 0.63~0.65, 0.46~0.49, respectively; with the offsets greater than 1 cm the ratios fall obviously, i.e., the impact of gamma on neutron decreases. With the same offset, the distribution of PSF of gamma is smaller than that of neutron, and the distribution of PSF of the two particles’ superposition is between that of gamma and tha