Source reconstruction for neutron coded-aperture imaging: A sparse method

Neutron coded-aperture imaging has been developed as an important diagnostic for inertial fusion studies in recent decades. It is used to measure the distribution of neutrons produced in deuterium-tritium plasma. Source reconstruction is an essential part of the coded-aperture imaging. In this paper, we applied a sparse reconstruction method to neutron source reconstruction. This method takes advantage of the sparsity of the source image. Monte Carlo neutron transport simulations were performed to obtain the system response. An interpolation method was used while obtaining the spatially variant point spread functions on each point of the source in order to reduce the number of point spread functions that needs to be calculated by the Monte Carlo method. Source reconstructions from simulated images show that the sparse reconstruction method can result in higher signal-to-noise ratio and less distortion at a relatively high statistical noise level.