Cryogenic apparatus is provided having first and second single-shot refrigerators and an enclosure for containing a coolant gas. First and second condensation surfaces are provided within the enclosure, the said surfaces being selectively cooled when in use by the respective first and second single-shot refrigerators such that coolant gas condenses on the surfaces as liquid coolant. A cold platform which, receives the liquid coolant from the condensation surfaces. The enclosure is adapted to provide a path for gaseous coolant between the first and second condensation surfaces, the path having a lower hydraulic impedance than that between each of the condensation surfaces and the cold platform.