Low magnification gas limiting aperture assembly for electron microscopy devices

摘要

The present invention pertains to scanning electron microscope devices with an improved design that allows for lower magnification capabilities without signal degradation. In particular, the design improvement is in the aperture carrier for the electron detector/differential pumping system therein. Advantages of this improvement include shorter working distances of a specimen under examination to obtain the same magnification for prior art type ESEM apparatus, lower magnification capabilities of an ESEM apparatus, better signal/noise ratio of the specimen and higher chamber pressures in which the specimen can be examined. Other features of the invention herein includes use of a variable displacement mount for holding the sample using a piston design which allows for variable detector positioning with respect to the specimen.