Abstract: Embodiments of the disclosed invention relate to providing cooling to instruments or other components. More particularly, hydrogen from a store is provided to pre-cool helium contained within a closed loop refrigeration circuit. Helium pre-cooled by the hydrogen, for example after expansion of the hydrogen in an expansion valve, is itself passed through an expansion valve, and applied to a heat load. The helium can be circulated through the refrigeration circuit using a compressor. The hydrogen used for pre-cooling the helium can be from a store of hydrogen that also provides fuel to a hydrogen consumer, for example for propulsion of a vehicle carrying the cooling system or for the production of electrical power. A hydrogen consumer can also be provided with hydrogen that has first been used to pre-cool the helium refrigeration circuit.

Abstract: A microminiature laminated heat exchanger for use in a cryogenic probe, and a method of manufacture. The heat exchanger has high and low pressure flow patterns etched into oxygen free copper sheets, with the flow patterns being tortuous paths promoting turbulent flow. The sheets containing the flow patterns are bonded into a laminated assembly in the shape of a cylinder, with a high pressure inlet and a low pressure outlet in a first end, and a high pressure outlet and a low pressure inlet in a second end. The high pressure flow path lies alongside the low pressure flow path, with flow in the two paths being in opposite directions, to accomplish counterflow heat exchange.