A cryogenic axial-centrifugal compressor for superfluid helium refrigeration

CERN's new project, the Large Hadron Collider (LHC), will use superfluid helium as coolant for its high-field superconducting magnets and therefore require large capacity refrigeration at 1.8 K. This may only be achieved by subatmospheric compression of gaseous helium at cryogenic temperature. To stimulate development of this technology, CERN has procured from industry prototype Cold Compressor Units (CCU). This unit is based on a cryogenic axial-centrifugal compressor, running on ceramic ball bearings and driven by a variable-frequency electrical motor operating under low-pressure helium at ambient temperature. The machine has been commissioned and is now in operation. After describing basic constructional features of the compressor, we report on measured performance

Cryogenic cooling system Brayton for 10 J/10 Hz Yb:YAG multi-slab based laser system at ELI-Beamlines project

We present design and operational prototype of cryogenic cooling system based on Bryton's cycle for 10J/10Hz Yb:YAG multi-slab laser system at ELI-Beamlines project