Study of the response function of a HPGe detector for low-energy X-rays

Accurate processing of low-energy X-ray spectra requires detailed knowledge of the detector response function. This has been determined for a high-purity germanium (HPGe) detector by using monochromatized synchrotron radiation in the 1–20 keV energy range. Due to the high peak-to-background ratio, the spectra reveal shapes that were hidden using previous detectors. In addition to escape peaks, features caused by electron interactions characterize the background shape: escape of photoelectrons and Auger electrons from the active part of the crystal and penetration of the electrode ones into the detector. The tunable incident radiation makes it possible to examine and identify these different features by fine scanning at the binding energies of the detector materials.