反应堆中子边缘增强效应成像初步研究

Neutron edge enhancement image is a recently developmental technique which is based not only on the amplitude like in the projection imaging but also on the contribution of phase alteration of the neutron beam. With the additional contrast from the difference of neutron refraction index in the sample which mainly leads to edge enhancement, this method can show more details about the neutron phase materials, especially some low attenuation contrast materials. Numerical simulation of neutron edge enhancement imaging is processed by MATLAB based on reflection theory and some experiments are carried out at a reactor using polychromatic thermal neutron beam line. The simulation and experiment results all show that a proper L/D condition would cause image enhancement at the edge of aluminum materials and the monochromatic neutron source isn't needed. The effect is related to L/D and the distance between sample and scintillator.