Monte Carlo Simulation Study on Optimization of Detection Efficiency and Spatial Resolution of Coated ⁿMCP

Since neutron sensitive microchannel plates (ⁿMCP) has high detection efficiency and the spatial resolution, combined with advanced readout electronics it can be a better choice for energy-resolved neutron imaging detectors. Compared with the matrix-doped ⁿMCP, the ⁿMCP based on Atomic Layer Deposition(ALD) has the advantages of less neutron sensitive material consumption and high secondary electron emission coefficient on the inner wall of the channel. Firstly, the typical neutron and gamma signal of ^natGd-doped ⁿMCP were studied experimentally. Geant4 simulation and theoretical calculation were performed to optimize the pore diameter, wall thickness, bias angle and coating thickness of the coated ¹⁰B₂O₃ ⁿMCP. It was shown that the thermal neutron detection efficiency was about 56% and the spatial resolution was about 22 μm when the coating thickness was 1 μm, the pore diameter was 10 μm, the wall thickness was 1 μm and the bias angle was 3°. The results are of great significance to the geometric parameter design of ⁿMCP used as energy-resolved neutron imaging detectors at CSNS.