采用Si薄膜的光子计数成像系统性能的研究  

Properties of photon counting imaging system with Si thin films

作　　者：赵菲菲[1,2] 刘永安[1] 胡慧君[1,2] 赵宝升[1] 

机构地区：[1]中国科学院西安光学精密机械研究所瞬态光学与光子技术国家重点实验室,西安710119 [2]中国科学院研究生院,北京100039

出　　处：《物理学报》2010年第10期7096-7104,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10878005)资助的课题~~

摘　　要：在陶瓷基底上利用电子束蒸镀方法制备了Si薄膜,用作感应读出方式光子计数成像系统的电荷感应层,并研究了薄膜的结构特征和表面形态.X射线衍射(XRD)测试和场发射扫描电子显微镜(FESEM)图像表明,沉积的Si薄膜为无定形态,由于陶瓷晶界的存在,薄膜较粗糙.搭建了相应的实验系统,对比了采用不同厚度Si薄膜时系统的空间分辨率、计数率、脉冲高度分布曲线等,发现薄膜的厚度对探测器的计数率影响较大.此外,实验还对比了采用相同电阻值的Si薄膜和常用的Ge薄膜时系统的性能.研究表明,采用Si薄膜时系统的畸变较小、计数率高、暗计数小。The Si thin films on ceramic substrates,which were fabricated by electron beam evaporation,were applied as charge induction layers in photon counting imaging system with induction readout.The structures and micrograph of Si thin films were studied.The X-ray diffraction（XRD） analysis and field emission scanning electron microscopy（FESEM） images indicate that the thin film has amorphous structure and is coarse due to the lattice boundary of ceramic substrate.The experimental setup was established and the detector resolution,counting rate,pulse height distribution curves etc.,with different Si film thickness were compared.The results suggest that the film thickness influences on spatial resolution less than on the counting rate.Moreover,the properties of the system with Si and Ge thin films of the same resistance were compared,which shows that the properties such as distortion,counting rate and dark count rate are better with the Si films.

关 键 词：探测器 光子计数成像 电荷感应 微通道板 

分 类 号：O484.41[理学—固体物理]