A sealed ceramic GEM-based neutron detector

The GEM-based neutron detector has flourished in the past decade. However, most of the GEM-based neutron detectors operate in the flow-gas mode, and the long-term performances of the detectors may be unstable due to the dynamic changes of atmospheric pressure and ambient temperature. In this work, a sealed ceramic GEM-based neutron detector with 100 mm $\times$ 100 mm sensitive area was developed at China Spallation Neutron Source (CSNS). Various characteristics of the detector were determined. These included the plateau curve, neutron beam profile, neutron wavelength spectrum, spatial resolution (FWHM: 2.77 ± 0.01(stat) mm), two-dimensional (2D) imaging ability, neutron detection efficiency and long-term counting rate instability (Relative Standard Deviation (RSD): 0.80%). The results revealed the good performance of the detector in sealed mode. Furthermore, the detector can be used for measurements of the direct neutron beam at CSNS.