CERN Accelerating science

European Organization for Nuclear Research

Cryogenic Saving Unit

Cryogenic Saving Unit


The technology is a novel configuration for cooling of superconductive magnets used for testing magnets and training personnel. It contains two parts, the cryostat vessel and the recovery vessel. When a quench occurs - loss of superconductivity resulting in a rapid rise of resistance and temperature - in the cryostat the pressure increases because of a restriction on the outgoing line. The liquid helium quickly goes back to the recovery vessel where it is saved for later use. The pressure in the cryostat drops when the quench passes. As a result of the hydrostatic level difference between the vessels and the pressure drop, the cryogen flows back to the cryostat and restarts the cooling.

Areas of expertise

Accelerators, Magnets and Cryogenic Technology


  • Testing magnets and training personnel on superconductive magnets.
  • Superconductive Power Devices (for example a Fault-Current Limiter) has potential for future applications.

Innovative features

A new design that separates the single vessel into a cryostat vessel and a recovery vessel. By using pressure changes and the hydrostatic level difference between the vessels the new design creates an automatic closed-circuit process.


  • Shortens the recovery period by a factor of three.
  • Saves up to 7,5 kg of helium per quench.


  • Shorter recovery period
  • Economy of cryogen fluid
  • Economy on energy


The design is most valuable in applications having repeated transitions.

Intellectual Property status

Ready for licensing. Patented technology. PCT filed. FR05 00861.

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