本文所讨论的复合板筒镜电子能量分析器,和通用的筒镜分析器一样,具有二级聚焦和传输率高的优点.其主要特点是:当一次入射束垂直入射于试样表面,激发出的次生电子以喷泉状通过弯曲的轨道绕过试样,重新会聚到试样背后的对称轴上.因此,在用于电子枪位于分析器外的扫描俄歇电子显微镜中作俄歇电子能谱仪时,可以缩短电磁物镜的工作距离,减小物镜的球差系数,增加一次电子束流密度,从而提高俄歇分析的灵敏度.其次,与电子枪在内筒中的简镜分析器相比,可以简化内筒的结构,并便于电子枪的调整.

The Combined Plane-Cylindrical Mirror Analyzer (PCMA) hag the advantage of high transmission and the possibility of second-order focusing, just like the conventional cylindrical mi ror analyzer (CMA). In the POMA all fountain electrons emitted from the specimen (electron source) on the cylinder s ooaxis will be focused behind the specimen on the axis after travelling through 180 degrees. By using PCMA as the electron energy analyzer in a scanning electron microscope (SEM), the working distance of the SEM magnetic objective lens could be shortened, and its spherical abberation reduced as compared with non-coaxial gun type CMA, thus the primary electron beam current density oould be increased. As a result, the sensitivity of the scanning Auger Mioroprobe (SAM) might be enhanced. Furthermore, the structure within the irrer cylinder of PCMA is much simpler than the conventional CMA with coaxial gun.