Evaluation of virtual point detector location in HPGe planar detector for 13-661 keV photon energies by using filter paper sources

One of the most important instruments in gamma ray spectroscopy is HPGe detector. Concept of virtual point detector was considered for Ge(Li) detector. On the basis of this concept, there is a point inside a Ge detector that can be regarded as a fictitious point detector hosting all the interactions. If there is really a point whose response can be considered similar to that of the whole real bulky detector, the geometrical considerations used in calibrations of the detector will be much simpler. This simplification is important, especially in measuring radioactivity of bulky sample. In this research, with using filter paper sources,the location dependence of virtual point detector for HPGe planar detector in 13-661 keV photon energy range was investigated.