A hybrid method for calculating absolute peak efficiency of germanium detectors

We propose a hybrid method using the Moens concept of effective solid angle for calculating absolute peak efficiency of germanium detectors for extended sources. The effective solid angle is evaluated according to Monte Carlo integration instead of conventional numerical integration. The proposed hybrid method was tested for point, disk, cylinder, and Marinelli-beaker sources with essentially identical results as compared with those calculated using conventional numerical integration. The off-axis effect of source positions and the absolute peak efficiency for cuboid sources were also analyzed to demonstrate the powerful capability of the proposed hybrid method.