Evaluation of the characteristics of a slow-scan CCD camera for a transmission electron microscope

The sensitivity, the signal to noise ratio (S/N) and the defective quantum efficiency (DQE) of the slow-scan CCD camera (SSC) for TEM, which has the CCD fibre-optically coupled to a high-resolution phosphor scintillator and no cooling device, were measured at 100 kV in order to understand characteristics of the SSC for electron exposure. The SSC had the dynamic range of almost four orders for electron intensity, and a linear relationship between the average number of incident electrons and the recorded image signal. The S/N curve of the image signals without the gain correction tended to take a constant value and the DQE of them tended to decrease drastically in high exposure region, but the gain correction contributed to improve the S/N and the DQE in the high exposure region. These characteristics of the SSC were compared with the previous results reported on the SSC with a YAG scintillator.