The quantum efficiency of the pn-CCD detector on the XMM satellite mission was determined in the spectral range between 150 eV and 15 keV. The unstructured entrance window of the device, which is formed by an ultrathin reverse biased pn-junction, results in an excellent spatial homogeneity with a good spectroscopic performance and high detection efficiency for low energy photons. The large sensitive thickness of the detector guarantees a high quantum efficiency for photons up to 10 keV. We give a review of the calibration techniques applied for quantum efficiency measurements at the Synchrotron Radiation Facility at the Institut d'Astrophysique Spatial in Orsay and the radiometry laboratory of the Physikalisch-Technische Bundesandstalt at the electron storage ring BESSY in Berlin. We summarize the applied data correction such as charge transfer loss and split event recognition and describe the data analysis to conclude in an absolute quantum efficiency of the pn-CCD.

Date Published: 22 October 1999
PDF: 11 pages
Proc. SPIE 3765, EUV, X-Ray, and Gamma-Ray Instrumentation for Astronomy X, (22 October 1999); doi: 10.1117/12.366552

Published in SPIE Proceedings Vol. 3765:
EUV, X-Ray, and Gamma-Ray Instrumentation for Astronomy X
Oswald H. W. Siegmund; Kathryn A. Flanagan, Editor(s)