[Evaluation of peak efficiency of high purity Ge detector in examination of volume samples]

The Monte Carlo code PEAK was developed to calculate the peak efficiency of Ge(Li) and high purity Ge( HPGe ) detectors to voluminous sources of cylindrical and Marinelli -type shapes. The accuracy of the PEAK code has already been verified for Ge(Li) detectors and in this study its accuracy to HP Ge detectors was investigated. First, the sensitive region of the HP Ge detector was determined from the combination of the collimated beam and the standard point source experiments. By using this shape of the sensitive region, the peak efficiencies to radioactive agar, activated alumina and manganese dioxide samples encapsulated in a cylindrical vessel were calculated and showed very good agreement within about several % with the experimental results.