Yamamoto K, Tanji T, Hibino M, Schauer P, Autrata R
Department of Electronics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
Microsc Res Tech. 2000 Jun 15;49(6):596-604. doi: 10.1002/1097-0029(20000615)49:6<596::AID-JEMT10>3.0.CO;2-A.
A new lens coupling television (TV) system using a YAG (Yttrium Aluminum Garnet: Y(3)Al(5)O(12) : Ce(3+)) single crystal screen has been developed for a high-voltage electron microscope (HVEM), and its performance is examined. The system, using a combination of YAG and lenses, is less damaged by high-energy electron irradiation and reduces the influence of X-rays on the image. YAG screens have not been used for lens-coupling systems, because the high refractive index (n = 1.84) of YAG results in a low light collection efficiency for emitted light. This disadvantage is overcome by combining a thin YAG disk screen (thickness; 100 microm) with a glass hemisphere whose refractive index is 1.81. We found that the light intensity is almost the same as that obtained with a conventional P22 powder screen and lenses system. The resolution is about 55 microm on the YAG screen, and this value is 1.3 times higher than that measured by the conventional system. Shading and distortion do not affect TV observation. Detection quantum efficiency, obtained after correction of the channel mixing effect, is about 0.1.
已为高压电子显微镜（HVEM）开发出一种使用YAG（钇铝石榴石：Y(3)Al(5)O(12) : Ce(3+)）单晶屏幕的新型透镜耦合电视（TV）系统，并对其性能进行了检测。该系统结合了YAG和透镜，受高能电子辐照的损伤较小，且减少了X射线对图像的影响。YAG屏幕此前未用于透镜耦合系统，因为YAG的高折射率（n = 1.84）导致发射光的光收集效率较低。通过将薄YAG圆盘屏幕（厚度为100微米）与折射率为1.81的玻璃半球相结合，克服了这一缺点。我们发现光强度与使用传统P22粉末屏幕和透镜系统时几乎相同。YAG屏幕上的分辨率约为55微米，该值比传统系统测量值高1.3倍。阴影和畸变不影响电视观察。校正通道混合效应后获得的探测量子效率约为0.1。
