A fast back-projection reconstruction method for fast neutron scatter imaging

A fast back-projection method is established. This method does not need to search all image space, but just to check and search the pixels inside the scope determined by scatter events. So the computational speed of image reconstruction is greatly improved. This method is applied to data from a simulation prototype of a neutron scatter camera with five detector elements. The results show that the reconstruction result is the same as the true point source at azimuth, and it takes only 3 seconds to process 1000 scatter events by this method, the angular resolution of reconstruction result is 8.0. The influence of the reconstruction parameters on runtime and resolution was analyzed,and the conclusion indicates that this method is of advantage to reconstruction the distribution of neutron sourcefor neutron detection in large field of view.