气体电子倍增器的研制及性能测试

Fabrication and measurement of gas electron multiplier

气体电子倍增器(GEM)以其独特的性能在辐射探测器领域得到了广泛的应用,对50μm厚聚酰亚胺(kapton)薄膜利用真空热蒸发和激光掩膜打孔法制作GEM膜,孔径100μm,孔距223μm,并封装流气式探测器,有效探测面积3mm×3mm。5.9keV55F e X射线测量了GEM在不同高压和混合气体比例时的脉冲幅度分布情况。讨论了高压和气体比例对探测器计数率和能量分辨率的影响。结果表明GEM具有较高的信噪比,能量分辨率可达18.2%。

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 55Fe 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%.