The invention relates to a method and a magnetoencephalography (MEG) measurement device. In the method there is determined the ending of a scheduled inactivity period of the MEG device. At the ending of the inactivity period a cryocooler of the MEG device is switched off. Helium is allowed to boil in the Dewar vessel of the MEG device when the MEG device is active and used to perform patient measurements. The boiled helium is collected via a compressor to an external storage tank. When a new inactivity period for the MEG device commences, the cryocooler is started anew and helium is let from the external storage tank in-to the Dewar vessel, where it is re-liquefied by the cryocooler. The compressor may be switched off when the cryocooler is switched on.

Provided are a cryogen recondensing system and a superconducting magnet apparatus including the same. The cryogen recondensing system includes a primary reservoir that stores cryogen for cooling a superconducting coil; a refrigerator that recondenses gas cryogen of cryogen stored in the primary reservoir; a secondary reservoir that stores gas cryogen; and a secondary reservoir tube that connects the primary reservoir to the secondary reservoir, through which the gas cryogen flows.

An evaporative cooling apparatus may include a heat transfer module having a vapor passage in fluid communication with a liquid refrigerant in a first container and a heat absorbing module having a drawing liquid selected to absorb the liquid refrigerant in the second container. The heat absorbing module also has a vapor chamber in the drawing fluid that receives vapor generated during evaporation of the liquid refrigerant. The vapor chamber has a selectively permeable membrane that: (i) transports the vapor to the drawing liquid, and (ii) blocks flow of the drawing fluid into the vapor chamber. The refrigerant may be liquid water, the vapor chamber may include a selectively permeable membrane having a pore size between 1 nm and 200 nm, and the drawing fluid may be glycerol.

A method is provided for precooling a cryostat having a hollow cold head turret into which a neck tube protrudes and connects an object to be cooled to the exterior of the cryostat, wherein a cold head having a cold head stage for cooling a cryogenic working medium may be introduced into the neck tube. During a condensation operation the cryogenic working medium flows through a heat pipe into an evaporator chamber which is thermally conductively connected to the object to be cooled. During a precooling phase a precisely fitting, thermally conductive short circuit block is inserted through the neck tube into the heat pipe to provide thermal conduction between the object to be cooled and a cooling device. The short circuit block is removed from the heat pipe after the target temperature is reached, and heat is subsequently transmitted through the heat pipe during a condensation operation.

A method is provided for precooling a cryostat having a hollow cold head turret into which a neck tube protrudes and connects an object to be cooled to the exterior of the cryostat, wherein a cold head having a cold head stage for cooling a cryogenic working medium may be introduced into the neck tube. During a condensation operation the cryogenic working medium flows through a heat pipe into an evaporator chamber which is thermally conductively connected to the object to be cooled. During a precooling phase a precisely fitting, thermally conductive short circuit block is inserted through the neck tube into the heat pipe to provide thermal conduction between the object to be cooled and a cooling device The short circuit block is removed from the heat pipe after the target temperature is reached, and heat is subsequently transmitted through the heat pipe during a condensation operation.

A cryogen cooling system to cool a superconducting magnet is disclosed herein utilizing embedded vertical tubing with a large heat exchanging surface area. The tubing encompasses the magnet which is further surrounded by a 4 Kelvin thermal shield for extended ride-through. In one embodiment, the system is a hyperpolarizer having an internal high-pressure gas storage for quench gas and to initiate cool-down. Aspects of the invention utilize a minimal volume of pressurized gas, for example, four (4) liters of pressurized gaseous helium in a 150 mL liquid helium system. As such, the prior vent stack has been removed, along with the helium vessel and quench paths/ducts. The method of using the system is further simplified during ramping while the cool-down process utilizing liquids supplied from external dewars has been eliminated. Significant advantages include reducing the helium volume (and cost associated therewith) and allowing for a hermetically sealed vacuum system that is leak-proof.

A cryocooler assembly including at least one remotely driven cryocooler operable between an ON-state of operation and an OFF-state of operation and defining a first stage of the cryocooler assembly. A liquefaction cup in fluidic communication with a cryogenic fluid reservoir, wherein a plurality of conduits thermally couple the liquefaction cup to the fluid reservoir and define a second stage of the cryocooler assembly. The cryocooler assembly further including one or more of a valve, a gas/liquid switch, an actuating support arm and a heat pipe coupled to the second stage of the cryocooler assembly to remotely disconnect a heat path generated by the at least one remotely driven cryocooler between the first stage and the second stage during the OFF-state of operation. A superconducting generator including at least one remotely driven cryocooler assembly and method of operating a cooling assembly for a superconducting generator utilizing at least one remotely driven cryocooler assembly are disclosed.

The present invention relates to a cryocooler suitable for gas liquefaction applications, that comprises a coldhead with one or more refrigeration stages; further comprising: a refrigerator compressor for distributing compressed gas-phase cryogen inside the coldhead; a heat exchanging coil arranged at least partially around the external region of the coldhead; at least one extraction orifice communicating a gas circulation circuit inside the coldhead with the heat exchanging coil; acting said extraction orifice/s as pass-through port/s which allow the gas inside the coldhead to flow through the inside of the heat exchanger coil for exchanging heat with the exterior thereof, and wherein the heat exchanging coil is adapted to connect and redirect the gas to one return port connected to the gas circulation circuit. Another object of the invention relates to a cryogen-gas liquefaction system and a method for liquefaction of gases that comprises said system.

Provided are a superconducting rotating machine which improves the cooling efficiency of a rotor by using schemes of passively or actively circulating a coolant and a cooling method thereof. The superconducting rotating machine includes a rotor supported rotatably about a rotation axis and including: at least one superconductive coil; and a central cavity; and a cooling apparatus disposed at an exterior of the rotor and configured to communicate with the cavity, wherein the cooling apparatus includes: a condenser configured to condense a gas coolant supplied through a gas coolant supplying pipe to generate a condensed coolant; a coolant circulating unit configured to supply the condensed coolant into the cavity, configured to recover a vapor coolant evaporated in the cavity into the condenser and configured to circulate the condensed coolant; and a forced circulating unit configured to actively circulate the condensed coolant into the cavity in response to the rotor being tilted.

A superconducting magnet cooling system is disclosed. The superconducting magnet cooling system includes a superconducting magnet; a liquid cryogen vessel for cooling the superconducting magnet; a heat exchanger device in fluid communication with the liquid cryogen vessel; a cryorefrigerator for heat exchange with the heat exchanger device; and a flexible connection device having high thermal conductivity and thermally connecting the cryorefrigerator and the heat exchanger device to provide vibration isolation of the cryorefrigerator from the heat exchange device.