Cold neutron imaging and efficiency measurements with a Boron-10 coated double-GEM detector

A 10B-coated cathode double-GEM neutron detector (BGEM) was developed as a 3He-free cold-neutron beamline detector using a single 10B4C converter cathode and a 512-channel APV25 orthogonal-strip readout over 10 × 10 cm2. The detector was tested at the HANARO Bio-REF beamline with a monochromatic 4.5 Å beam (En=4.03meV). The detection efficiency relative to a 6Li-based Ce:LiCAF reference detector was ɛBGEM=(8.69±0.20)%(stat.). The pulse-height spectrum was qualitatively consistent with Geant4 energy-deposition simulations, and Cd-mask imaging yielded σ=(555⊕102)μm, corresponding to FWHMLSF=(1.31⊕0.24)mm. These results establish a cold-neutron beamline benchmark for a single-converter BGEM detector with full-strip APV25 readout.