Simulation and performance study of ceramic THGEM

THGEMs based on a ceramic substrate have been successfully developed for neutron and single photon detection. The influences on thermal neutron scattering and internal radioactivity of both ceramic and FR-4 substrates were studied and compared. The ceramic THGEMs are homemade, of 200 μm hole diameter, 600 μm pitch, 200 μm thickness, 80 μm rim, and 50 mm×50 mm sensitive area. FR-4 THGEMs with the same geometry were used as a reference. The gas gain, energy resolution and gain stability were measured in different gas mixtures using 5.9 keV X-rays. The maximum gain of a single layer ceramic THGEM reaches 6×10⁴ and 1.5×10⁴ at Ne+CH₄=95:5 and Ar+i-C₄H₁₀=97:3, respectively. The energy resolution is better than 24%. Good gain stability was obtained during a more than 100 hour continuous test in Ar+CO₂=80:20. By using a ²³⁹Pu source, the alpha deposited energy spectrum and gain curve of the ceramic THGEM were measured.