极端紫外波段碱卤化物光阴极材料量子效率计算  

Calculation of quantum efficiency of alkali halide photocathode materials in the extreme ultraviolet region

作　　者：李敏[1,2] 尼启良[1] 陈波[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所应用光学国家重点实验室,长春130033 [2]中国科学院研究生院,北京100049

出　　处：《物理学报》2009年第10期6894-6901,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:40774098;60677043)资助的课题~~

摘　　要：为了满足极端紫外波段微通道位敏阳极光子计数探测器研究的需要,研究了碱卤化物光阴极材料的量子效率.由于光阴极材料的光电发射电流主要是由次级电子形成的,给出碱卤化物光阴极材料次级电子发射的理论模型,推导出次级电子产出的计算公式,针对光子能量30—250eV范围内,计算并分析了光阴极材料厚度和光入射角对次级电子产出的影响.分析结果显示,光阴极材料厚度大于100nm并且掠入射角大于临界角,是获得高次级电子产出的最佳条件.最后,应用推导的公式分析20种碱卤化物在能量30—250eV范围内次级电子产出的光谱响应特性,特性分析显示,次级电子产出的光谱响应峰值位置在材料的共振吸收波长位置.In order to meet the requirement of microchannel plate position-sensitive photon counting detector in the extreme ultraviolet region,the quantum efficiency of alkali halide photocathode was studied.Based on the fact that the photoemission from photocathode is formed by secondary electrons,the theoretical model of secondary electron emission for alkali halide photocathode was presented,and the formula of secondary electron yield was obtained.For photon energy ranging from 30 to 250 eV,the effect of the thickness of photocathode and the incidence angle on the secondary electron yield was calculated and analyzed, the result showed that when the thickness was higher than 100 nm and the grazing angle was larger than the critical angle of photocathode material, high secondary electron yield was obtained. Finally, according to the derived formula, the spectrum response of the secondary electron yield for twenty alkali halides was analyzed, and the result showed that the position of the peak yield was in accordance with the resonant absorption of photocathode materials.

关 键 词：极端紫外 碱卤化物 光阴极 次级电子 

分 类 号：O462.3[理学—电子物理学]