A novel method to improve the spatial resolution of GEM neutron detectors with a stopping layer

This paper proposes a novel method to improve the spatial resolution of ceramic GEM detectors by adding a stopping layer on top of the solid 10B4C neutron converter. This will restrict the emission of the secondary ion products of large angles and consequently improve the spatial resolution. The Monte Carlo program FLUKA is used to validate the method, and the verification experiments are carried out at the beam line #20 (BL20) of the China Spallation Neutron Source (CSNS). The experimental results are approximately in agreement with the simulations. The measured spatial resolution is 1.61 mm for the GEM neutron detector operated at ambient pressure with a 1-μm-thick 10B4C converter, and it is improved to ~0.8 mm by coating a 3-μm-thick titanium on top of the 10B4C converter.