1000B型SEM普通三极电子枪低加速电压像的改进  

To Improve the Resolation of Low Accelerative Voltage Image by Ameliorating Conventional Triode Electron Gun of SEM

作　　者：姜新力[1] 章一鸣[1] 

机构地区：[1]中国科学院北京科学仪器研制中心

出　　处：《电子显微学报》1992年第1期63-67,共5页Journal of Chinese Electron Microscopy Society

摘　　要：通过对kyky—1000B型扫描电镜普通三极电子枪的不同几何尺寸、低加速电压下的束斑直径电子枪亮度、信噪比的测量,以及对低压高倍像的观察,探讨了观察低压象的条件。实验表明,在正常状态下加速电压低于5KV时,由于空间电荷效应,电子束斑点急骤加大;亮度急骤下降;致使图象分辩率变坏;S/N差,观察较高倍率很困难。对不同加速电压下缩短1000B SEM的阳—栅极间距离,使电子束斑直径明显减小,亮度提高半个数量级,使图象分辩得到明显改善。Usually, the image resolution of SEM is good when the aecelerative voltage is higher than 10KV, and poor when it is less than 1-4KV, because of space charge effect, and the brigtness of electron beam is decreased rapid-ly. In thes paper, the distance between anode-grid of kyky 1000B SEM is reduced. In this case the image resolu-tion under low accelerative voltage has leen improved, as a resalt, the diameter of electron beam is reduced distinctly, and it' s brightness is increased.

关 键 词：SEM 电子枪 加速电压像 生物样品 

分 类 号：Q－336[生物学]