Cryostat and nuclear magnetic resonance imaging apparatus including a cryostat
AssigneeHitachi, Ltd.
InventorsNorihide Saho, Takeo Nemoto, Mitsuru Saeki
Life of this patent
Estimating the term…
Abstract
A magnetically shielded cryostat, e.g. in a MRI imaging apparatus, has a heat-insulating tank having an outer wall. A magnetic shield is spaced from the tank, covers at least partly the outer wall of the tank and is not supported by the tank. A refrigerator having a cooled member extends into the tank. In order to avoid direct transmission of vibration of the refrigerator to a center region of the shield, the refrigerator is supported on the magnetic shield by at least one elongate support member connected to the shield only at or close to the ends of the shield.
Claims20
A cryostat having
- (a) a heat-insulating tank having an outer wall and two opposite ends and a longitudinal direction connecting said ends,
- (b) a structure at least partly enclosing said tank and extending along said tank said structure comprising one or more sheet members covering said outer wall of said tank and spaced from said outer wall, said structure not being supported by said tank, and
- (c) a refrigerator having a cooled member extending into said tank through said outer wall,
- (d) said refrigerator being mounted on said structure by at least one support member which is connected to said structure at least one location spaced from a central transverse plane of said tank and proximate to an end portion of said one or more sheet members.
A cryostat having
- (a) a heat insulating tank having an outer wall,
- (b) a refrigerator having a cooled member extending into said tank through said outer wall,
- (c) a first support member for said refrigerator of bar shape and having opposite ends, said refrigerator being mounted on said first support member away from its said ends, the first support member being spaced from the tank, and
- (d) a structure at least partly enclosing said tank and extending along said tank including at least one second support member supporting said ends of said first support member proximate to end portions of said structure, said second support member not being supported by said tank.
A magnetically shielded cryostat having
- (a) a heat-insulating tank having an outer wall and opposite ends,
- (b) a magnetic shield spaced from said tank around said tank having end members facing said ends of the tank and side members extending between said end members, said shield not being supported by said tank,
- (c) a refrigerator having a cooled member extending into said tank through said outer wall,
- (d) a bar supporting said refrigerator at a central location of said tank, said bar being carried at its opposite ends by said end members of the shield.
In a magnetically shielded cryostat having
- (a) a heat-insulating tank having an outer wall comprising opposite ends and at least one side wall connecting said ends,
- (b) a magnetic shield spaced from the tank and covering at least partly said side wall of said tank, and not supported by said tank,
- (c) a refrigerator having a cooled member extending into said tank,
- the improvement that, in order to avoid direct transmission of vibration of said refrigerator to a center region of said shield, said refrigerator is supported on said magnetic shield by at least one support member connected to said shield only at or close to at least one end of the shield.
In a magnetically shielded cryostat having a heat-insulating tank having an axis and axial ends and being cooled by a refrigerator, and a magnetic shield around said tank supporting said refrigerator, the improvement that the weight of said refrigerator is transmitted to said shield at one or more locations each spaced from a central radial plane of said tank and proximate to end portions the axial length of the shield.
A nuclear magnetic resonance image apparatus having a cryostat tank, a superconducting magnet coil mounted in said cryostat tank and having an axis, a magnetic shield at least partly surrounding said cryostat tank and extending in the direction of said axis, a refrigerator for cooling said cryostat tank and support means for supporting said refrigerator on said magnetic shield, said support means being connected to said magnetic shield at least one location spaced axially from said axially central region of said cryostat tank and proximate to an end of said magnetic shield.
Dependencies are inferred from the claim text.