Performance Study And Applications Of THGEM

The Micro-Pattern Gaseous Detectors(MPGD) have been experienced a flourishing development in the past decades. Among which the Thick Gaseous Electron Multiplier(THGEM) has achieved great success, because it is very robust, has high gas gain, and is easy to be produced by PCB factories within relatively low costs.The traditional THGEM detector is produced by drilling a lot of regular holes on a copper-coated PCB substrate, and then etching the edge copper to make small insulated rings(the so-called rims) around all of the holes. And the process can be completed in PCB factories. The article is based on the domestic PCB factory to develop ceramic, FR4, PTFE, and Kapton which are four type substrates THGEM. And four type substrates THGEM have the same geometric parameters. By using the 5.9 ke V X-rays, the gas gain, energy resolution were measured in different gas mixtures to four type substrates THGEM, respectively. Among them, detailed introduces the ceramic THGEM detection of neutrons, for five layer ceramic substrate, the ceramic THGEM detection of neutrons detector efficiency is better 12%, position resolution of 2.95 mm, γ ray rejection ratio was 4.6‰. And developed one of the most delicate THGEM, which is the laser drilling THGEM. Whose holes diameter of 100 um, pitch of 300 um, thickness of 100 um. In the working gas of Ar + i C4H10=97:3, the maximum gain of double layer laser drilling THGEM is 5×104, the energy resolution of double layer laser drilling THGEM is better than 24%, and can be long-term stable working.A THGEM-based 2D position detector is developed for low energy electron detection. The spatial resolution is less than 200 um in 50 mm×50 mm sensitive area. The THGEM is homemade with 150 um holes diameter, 400 um pitch, and 100 um thickness. By using the 5.9 ke V X-rays, the gas gain, energy resolution were measured in different gas mixtures. The maximum gas gain of single and double layer THGEMs reach 1×104 and 6×104, respectively, and the energy resolution is better than 23% for both single and double layer THGEMs, The influences of film’s thickness, air-layer’s thickness, etc., on the electron transfer efficiency and transverse diffusion were simulated by Geant4. And the transverse diffusion of the electron avalanche was also simulated by Garfield. According to the simulation results, the design and structure of the detector was optimized.