High Performance Long-Life Cooler for Transportable Gamma Ray Detectors

This proposal describes a transportable cryocooler to be used for cooling High Purity Germanium (HPGe) detectors, commonly used for the detection of gamma rays. HPGe detectors are highly suitable for identifying nuclear materials, which is of great interest in the Department of Homeland Security (DHS) applications. HPGe detectors need to operate near 110 K requiring refrigeration. High cooling performance is highly desirable and can be accomplished by means of a compact, low-vibration, efficient cryocooler. Various existing cryogenic refrigeration systems are thought not to be applicable for the current DHS application either for reasons of excessive vibration or system mass, or for lacking reliability and efficiency. To address these refrigeration issues, we propose to develop a high performance pulse tube cooler. High frequency pulsetube coolers (PTCs) represent the most promising technology for achieving reliable lightweight cryocoolers. Applications of this cooler include cooling of infrared and gamma ray detectors, cooling of electronics, and the biomedical industry.