Spectral response of the EPIC-pn detector: basic dependences
  One of the three cameras behind the X-ray telescopes on board XMM-Newton is equipped with a pn CCD detector. Here the current status of the pn spectral response calibration is summarized. Several parameters describing the spectral response of the EPIC-pn detector show spatial dependencies. E.g. spectral resolution and single- to double-pixel event ratios are functions of the charge transfer losses and therefore depend on the distance to the read-out node of the CCD (the RAWY detector coordinate). 
F. Haberl, U.G. Briel, K. Dennerl, V.E. Zavlin (MPE, Garching)