Development of epithermal neutron camera based on resonance-energy-filtered imaging with GEM

An epithermal neutron camera based on energy-filtered imaging with gas electron multipliers was developed. Epithermal neutron imaging is achievable without time-of-flight detection of neutrons by using a resonance filter and a thermal neutron absorber. This technique is applicable to compact accelerator-based neutron sources. Blurring of epithermal neutron images caused by neutron scattering in the Ag resonance filter and the B 4 C sheet (used as a thermal neutron absorber) was investigated experimentally. The spatial resolution for epithermal neutrons with energies in the range 4.2 to 6.3 eV (corresponding to the resonance peak of 109 Ag) was estimated to be 1.9±0.5 mm in a prototype detector.