GEM探测器的计数性能研究  

Counting Properties of Gas Electrons Multiplier

作　　者：苏青峰[1] 夏义本[1] 王林军[1] 汪琳[1] 刘健敏[1] 史伟民[1] 

机构地区：[1]上海大学材料科学与工程学院电子信息材料系,上海200072

出　　处：《上海有色金属》2005年第3期110-113,共4页Shanghai Nonferrous Metals

基　　金：国家自然科学基金(60277024);上海市纳米专项(0452nm051);上海应用材料研究与发展基金(0307)

摘　　要：采用真空热蒸发法在50μm的聚酰亚胺薄膜上蒸镀5μm^8μm的铜层,并用激光掩模打孔法在其上制备了孔径80μm、孔间距285μm的GEM复合薄膜,成功组装了20mm×20mm的GEM探测器。对GEM探测器在55Fe X射线(5.9keV)辐照下进行了脉冲幅度分布谱测试,讨论了漂移区电场、ΔGEM电场、收集区电场对探测器记数的影响。结果表明,随着漂移区电场的增加,计数先增加后减小,在13kV/cm时达到最大值9.7×104。随着ΔGEM电场的增加,记数呈指数增长,最大可达1.2×104。随着收集区电场的增加,计数增大并趋向饱和,最大可达1.3×105。A GEM with an effective area of 20mm × 20mm was assembled based on GEM composite grid fabricated by thermal evaporation and laser mask perforating method. The pulse-height spectra of GEM for 5.9keV ^55 Fe X-ray were tested and the effects of drift electric field, △GEM electric field and transfer electric field on counts of GEM were studied. Results indicated that counts of peak first increase and then decrease with the change of the drift electric field from 10kV/cm to 19kV/cm, the maximum counts reach 9.7 × 10^4 at the field of 13kV/cm. Counts of X-ray peak increase with the increase of △GEM electric field and transfer electric field, and the maximum counts reach 1.2 × 10^4 and 1.3 × 10^5, respectively.

关 键 词：电子倍增器 X射线 工作电场 计数 

分 类 号：O572.212[理学—粒子物理与原子核物理]