Pressure control system for zero boiloff superconducting magnet
AssigneeGeneral Electric Company
InventorPhillip William Eckels
Life of this patent
Estimating the term…
Abstract
A pressure control system for the cryogen pressure vessel of a helium cooled superconducting magnet assembly including a helium gas recondenser to return liquid helium to the helium supply including a temperature sensor proximate to the recondenser to provide a control signal for maintaining a preselected temperature of said recondenser in order to maintain a preselected pressure within said helium vessel above the pressure outside the vessel and further including an indication of the thermal conductance across the interface between the recondenser and the cryocooler which cools the recondenser.
Claims20
A zero boiloff cryogen cooled recondensing superconducting magnet assembly including superconducting magnet coils suitable for magnetic resonance imaging comprising:
- a cryogen pressure vessel to contain a liquid cryogen reservoir to provide cryogenic temperatures to said magnet coils for superconducting operation;
- a vacuum vessel surrounding said pressure vessel and spaced from said pressure vessel;
- a cryocooler;
- a recondenser positioned in the space between said pressure vessel and said vacuum vessel and thermally connected by a thermal interface to said cryocooler to recondense, back to liquid, cryogen gas provided from said pressure vessel;
- means to return the recondensed liquid cryogen to said pressure vessel;
- and
- pressure control means to control the cryogen gas pressure within said pressure vessel above the pressure outside said pressure vessel;
- a temperature sensor positioned outside said cryogen pressure vessel proximate to, and sensing the temperature variations at, said thermal interface;
- said pressure control means being responsive to said temperature sensor to control the cryogen gas pressure within said cryogen pressure vessel in order to avoid cryopumping.
A zero boiloff liquid helium cooled recondensing superconducting magnet assembly suitable for magnetic resonance imaging comprising:
- a helium pressure vessel to contain a liquid helium reservoir to provide cryogenic temperatures to said magnetic resonance imaging magnet assembly for superconducting operation;
- a recondenser and a cryocooler for cooling said recondenser to recondense helium gas formed in said pressure vessel back to liquid helium;
- pressure control means to maintain the helium gas pressure within said helium pressure vessel above surrounding atmospheric pressure to avoid cryopumping;
- and
- a temperature sensor positioned proximate to said recondenser outside said helium vessel to provide a control signal responsive to the temperature of said recondenser;
- and pressure control means controlling the temperature of said recondenser at a preselected level to maintain said helium gas pressure within said pressure vessel in response to said control signal;
- whereby a sensor positioned within said helium vessel and associated mechanical leads through said helium vessel are avoided.
Dependencies are inferred from the claim text.