By cooling a metal cylinder surrounding the He-vessel in a superconducting magnet, reduced cryogen boil-off can be achieved.

Rate of cryogen (liquid helium) evaporation in superconducting magnets, usually measured in liters of liquid per hour. The boil off rate of cryogen increases during ramping of the magnet and with eddy currents induced in the cryoshields by pulsed field gradients. In calculating cryogen consumption additional transfer and filling losses have to be considered.

See also Cryoshielding and Helium.

Cryostats are devices for maintaining a constant low temperature (as by means of liquid helium used in MRI). They require vacuum chambers with thermal isolation.

See also Dewar, Cryoshielding and Boil off Rate.

See Magnetic Shielding, Cryoshielding and Faraday Shield.