Performance study of trial M-THGEM

Background: M-THGEM is a new type of electron multiplier, which is developed with a high gain, good stability and uniformity based on THGEM. With the successful application of small area M-THGEM, the large-area M-THGEM is proposed based on large-volume gas detector. Purpose: The production of large-area M-THGEM is difficult compared with the small one with more holes and more stable instruments. To meet the requirements of large-area gas detectors, the performances of the large-area M-THGEM need to be measured and researched, which will provide a guidance on the process and design of the M-THGEM. Methods: The M-THGEM membrane was loaded into a chamber to complete the test under the conditions of ⁵⁵Fe/X-ray source (5.9 keV) and working gas Ar:iC₄H₁₀ = 97:3. The performance of gain, energy resolution, uniformity and long-term stability can be tested. Results: Based on the small area M-THGEM, the research and design of large-area M-THGEM with 200×200mm2 were finished. The basic performances were measured. The results show that the gain with the working gas of Ar:iC₄H₁₀ = 97:3 can reach to 6 × 10 ³ , and the energy resolution of the ⁵⁵Fe /X-ray source (5.9 keV) reaches 29.4% with a good gain uniformity and stability. Conclusion: At present, the production and measurement of the large-area M-THGEM has been finished. The M-THGEM of 200×200mm2 shows a good performance, which will provide many references for the future design.