Evaluation of high-purity germanium detector performance at elevated temperatures and conceptual design considerations for a closed, self-contained germanium photon spectroscopy system using a solid melting cryogen

Abstract

It is concluded that the utility of HPGe detector systems may be enhanced through the use of solid, non-volatile cryogens.

A review of the applicability of Cadmium Telluride (CdTe) and Mercuric Iodide (HgI₂) room temperature semiconductor detectors for high-resolution gamma-ray spectroscopy was undertaken. It was concluded that no further evaluations with respect to these detectors were justified because of their limited geometric efficiency and intrinsic limitations such as incomplete charge collection, polarization, and crystal inhomogeneities.

Attention returned to germanium detection systems, since recent efforts in improving these detector systems have been so successful and their operating record has been so dependable over the past several years. However, cooling with liquid nitrogen (LN) has limited their application in some field monitoring situations. The study, therefore, was directed toward the investigation of alternate cooling methods for germanium detection systems and designing a system which would enhance their use in a variety of remote field conditions. The cooling capabilities of selected solid melting cryogens and the operating performance of a high-purity germanium (HPGe) detector at elevated cryogen melting temperatures were evaluated.