Numerical simulation of neutron penumbral imaging

Penumbral imaging has high sensitivity, which will be the main technical method of neutron imaging in inertial confinement fusion (ICF) experiments. Based on the requirement of neutron penumbral imaging, two-dimensional image of neutrons transport in the coded aperture is simulated by Monte Carlo method, with the biased sampling skill and surface-flux replaced by volume-flux skill. The source image is obtained by reconstruction program. According to the simulation result, the 5 cm thick W bulk is selected as the shileding material and the optimized aperture outer radius is 1 cm.