Practical Electron Microscopy and Database

The detector envelope function can be split into two main parts: i) The part due to the scattering processes taking place in the scintillator and fiber optical coupling; ii) The part arising when the continuous wave function is delivered to the imaging matrix with a finite pixel size. The situation is more complicated due to the fact that the detector has different transfer characteristics for the signal and the noise which are represented by the modulation transfer function (MTF) and the noise power spectrum (NPS) respectively. Note that the profiles of these two functions vary slightly from camera to camera depending on the type and thickness of the scintillator, pixel size etc.