Performance of an Improved TEM SDD Detector

External SDD systems can also replace Si(Li) detectors on existing microscopes and offer many of the advantages of the in-situ SDD systems. Since the SDDs do not operate at liquid nitrogen temperatures, the insulation gaps in the nosepiece/collimator assemblies can be reduced or eliminated. Also, the detector window and the associated support frame are no longer used. This means that the detecting area can be moved closer to the sample improving the solid angle for signal collection. In addition, the fact that the detector operates at -20C to -30C instead of cryogenic temperatures means that ice buildup on the detector is no longer an issue. One limitation to increasing the solid angle is that the detector must fit through the port in the sample stage area. While detectors are being made with larger and larger active areas, if they can’t fit through the microscope port they are useless.