  Avalanche photodiodes are commonly used as detectors for low energy x-rays.
In this work we report on a fitting technique used to account for different
detector responses resulting from photo absorption in the various APD layers.
The use of this technique results in an improvement of the energy resolution at
8.2 keV by up to a factor of 2, and corrects the timing information by up to 25
ns to account for space dependent electron drift time. In addition, this
waveform analysis is used for particle identification, e.g. to distinguish
between x-rays and MeV electrons in our experiment.
