Abstract: A germanium gamma-ray detector contained in a vacuum insulated cryostat is provided. The present invention provides a low-cost, high-performance, and highly reliable cooling system for germanium detectors. Moreover, the present invention provides a germanium detector operating environment that meets all the requirements for optimum performance of such detectors incorporating said cooling system. A self-cleaning cooler includes a counter-current heat exchanger which is received within a cooler housing. A removable cryostat is provided for being carried by the cooler housing. A capsule cold finger provides the cooling path to germanium detector element. A centering spacer/isolator is provided for maintaining the position and supporting the weight of the detector in an end cap without conducting an excessive amount of heat into the detector. A capsule flange is provided to substantially close the volume within the end cap. The heat exchanger and the throttle capillary of the cooler cool the cold block.