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The cryogenic infrastructure of the station for testing LHC prototype superconducting magnets in superfluid helium below 2 K has been upgraded. Liquid nitrogen precooling has permitted to increase the liquefaction capacity of the refrigerator. The addition of cold centrifugal compressors with a pressure ratio of 3:1 has boosted the capacity of the warm pumping unit. To ensure adaptation of the pumping capacity, a heater-and-valve box allows to bypass the cold compressors. This box also comprises a 32 kW electrical heater for warming up the low-pressure gaseous helium before it enters the volumetric warm pumping unit. Possible impurities in the helium returning from the subatmospheric circuits are trapped in a freeze-out helium cleaner. Automatic process control and supervision permit unattended operation and optimal management of the helium inventory.

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