CALCULATION ON PLANE-CYLINDRICAL MIRROR ENERGY ANALYZER.

The Combined Plane-Cylindrical Mirror Analyzer (PCMA) has the advantage of high transmission and the possibility of second-order focusing, just like the conventional cylindrical mirror analyzer (CMA). In the PCMA all fountain electrons emitted from the specimen (electron source) on the cylinder's coaxis 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 could be increased. As a result, the sensitivity of the Scanning Auger Microprobe (SAM) might be enhanced. Furthermore, the structure within the inner cylinder of PCMA is much simpler than the conventional CMA with coaxial gun.