Development of epithermal neutron camera with resonance filters

For measurement of spatial distribution of epithermal neutron source in BNCT, we propose an epithermal neutron camera based on a gas electron multiplier (GEM) and the filter that has a resonance in epithermal energy region. A prototype detector that consisted of GEM with a neutron to charged particle converter of ¹⁰B and a resonance filter of Ag was constructed. Difference in the response function between with and without the resonance filter was found in the epithermal region as a clear resonance dip, therefore the epithermal neutron detection with the prototype detector was successfully demonstrated.