Cryocoolers for the ARIEL Cryogenic Test Rig

RAL Space are designing the Cryogenic Test Rig (CTR) for the ARIEL payload module (PLM). It consists of a cryogenic shroud and a warm interface plate. Cooling is applied directly to the shroud using cryocoolers, attached via high purity aluminium thermal straps. The test rig requires up to 100 W of cooling at a cold head temperature of 20 K, which has been calculated based on extensive thermal modelling of the system. Margin on this heat lift would ideally be included to account for any modelling inaccuracies, with 50% assumed during the preliminary design phase. A single stage cooler would be preferred, and we expect that multiple coolers would be needed.