Implementation and operation of a fiber-coupled CMOS detector in a low energy electron Microscope.

The intrinsically weak signals in ultrafast electron microscopy experiments demand an improvement in the signal-to noise ratio of suitable electron detectors. We provide an experience report describing the installation and operation of a fiber-coupled CMOS based detector in a low energy electron microscope. We compare the detector performance to the traditional multi-channel-plate-based setup. The high dynamic range CMOS detector is capable of imaging spatially localized large intensity variations with low noise. The detector is blooming-free and overexposure appears uncritical. Overall, we find dramatic improvements in the imaging with the fiber-coupled CMOS detector compared to imaging with our previously used multi-channel-plate detector.