HPGe vs NaI

Every radionuclide of concern in homeland security naturally emits a unique set of one or more gamma ray energies from which it can be uniquely identified. To make identifications accurately, one needs to be able to measure these energies to approximately 0.1%. HPGe detectors can provide this level of accuracy while NaI detectors provide only about 6% and the best photoconductive CZT detectors provide approximately 2%. The polycrystalline CZT inductive radiation detectors (iRD) operating at room temperature are expected to achieve energy resolution much better than that of CZT photoconductive detectors meeting homeland security requirements.

Based on: ORTEC » (HPGe) Radiation Detectors