Image Enhancement for High frame-rate Neutron Radiography

High frame rate neutron radiography has been utilized to investigate two-phase flow in a metallic duct. However, images obtained by high frame-rate neutron radiography suffered from severe statistical noise due to its short exposure time. In this study, a spatio-temporal filter was applied to reduce the noise in the sequence images obtained by high frame-rate neutron radiography. Experiments were performed at the B4-port of the Research Reactor Institute, Kyoto University, which has a thermal neutron flux of 5.0×107 n/cm2s. Results were also compared with those obtained at the JRR-3, the Japan Atomic Energy Institute,with athermal neutron flux of 1.6×108n/cm2s.