Simulation and performance study on the four type substrates of domestic thick gaseous electron multiplier

Abstract:

Ceramic-based Thick Gaseous Electron Multipliers (THGEMs) have been successfully applied to neutron detection. The influences of ceramic, FR4, kapton, and PTFE substrates on the thermal neutron scattering and absorption were studied and compared by Geant4 software. The ceramic-THGEMs, FR4-THGEMs, kapton-THGEMs and PTFE-THGEMs are homemade in PCB factory, which have the same geometric parameters such as aperture of 200 μm, hole spacing of 600 μm, thickness of 200 μm, insulation ring width of 80 μm, and sensitive area of 50 mm × 50 mm. The gas gain, energy resolution and gain stability were measured using 5.9 keV X-rays, four different type substrates THGEM can work normally. The maximum gain of a single and double layer ceramic THGEMs reach 1.2×104 and 4×104 in Ar + CO2 =80:20, respectively. The energy resolution is better than 24.4% in Ar + iC4H10 = 97:3. Good gain stability was obtained during a more than 100 hours continuous test. By using a 239Pu source, the alpha deposited energy spectrum and gain curve of the ceramic THGEM were measured.

Key words:THGEM; Ceramic substrate; Thermal neutron