Fabrication and measurement of gas electron multiplier

Gas electron multiplier (GEM) with special performance has been widely used in the field of radiation detectors. In this work, GEM film was fabricated using a 50μm -thick kapton film by the thermal evaporation and laser masking drilling technique. GEM film has many uniformly arrayed holes with a diameter of 100μm and a gap of 223μm. It was then set up to a gas-flowing detector with an effective area of 3×3cm~2, 5.9keV X-ray generated from a ()~(55)Fe source was used to measur the pulse height distribution of GEM operating at various high voltage and gas proportion. The effect of high potential and gas proportion on the count rate and the energy resolution was discussed in detail. The results indicate that GEM has a very high ratio of signal to noise and better energy resolution of 18.2%.