Abstract: A burst disk assembly has a burst disk which is interposed within the high pressure relief vent of a superconducting magnet. The burst disk is a composite design constructed of a solid carbon graphite center surrounded by an integrally formed stainless steel ring. A captured burst disk flange insures proper placement and seating of the burst disk during replacement and supports the burst disk so as to prevent it from falling or dropping out of the assembly during replacement of the ruptured burst disk. A deformable gasket contiguous to the burst disk seals the burst disk to the captured burst disk flange when the disk and the flange are pressed together. Attachment bolts are used to provide even application of pressure along the face of the burst disk and the captured burst disk flange.

Abstract: A burst disk assembly has a burst disk which is interposed within the high pressure relief vent of a superconducting magnet. The burst disk is a composite design constructed of a solid carbon graphite center surrounded by an integrally formed stainless steel ring. A captured burst disk flange insures proper placement and seating of the burst disk during replacement and supports the burst disk so as to prevent it from falling or dropping out of the assembly during replacement of the ruptured burst disk. A deformable gasket contiguous to the burst disk seals the burst disk to the captured burst disk flange when the disk and the flange are pressed together. Attachment bolts are used to provide even application of pressure along the face of the burst disk and the captured burst disk flange.

Abstract: A pressure relieving venting system for a liquid helium superconducting magnet to vent cryogen gas upon a magnet quench including a burst disk closing the venting system during normal superconducting operation and sandwiched between a peripheral gasket assembly maintained under constant pressure by a plurality of axially extending bolts, spring washers and nut assemblies to preclude helium gas leakage in the absence of the disk bursting under excessive pressure.

Abstract: A recondensing zero boiloff superconducting magnet assembly utilizing a cryocooler with a compressible indium gasket positioned between the cryocooler and the recondenser and with the gasket containing a plurality of spaced parallel grid wires with interconnecting web segments of a lesser thickness interconnecting the mid sections of ends of adjacent wires to facilitate compression of the gasket to control improved thermal conductivity while minimizing the pressure and forces on the assembly.

Abstract: A passive non-electric pressure control system for a superconducting magnet cryogen vessel to maintain internal pressure above the outside pressure to avoid cryopumping utilizes a passive thermal conductor extending from the outside atmosphere into the vessel. The selective amount of penetration of the thermal conductor into the cryogen vessel controls the amount of heat transferred to the interior of the vessel and thus controls the internal pressure of the vessel.

Abstract: An indium gasket having a configuration which allows the indium to reach its yield point at a relatively low contact pressure. The indium gasket is provided with a multiplicity of openings which are filled by the deforming indium during compression between the cryocooler and the cryocooler interface sleeve of a superconducting magnet system. The creation of openings in the gasket has the effect of decreasing the mechanical interface pressure at which the indium yields. The indium flows at a mechanical interface pressure that does not exceed the structural strength requirements of the cryocooler. The indium flows into the empty spaces formed by the openings, thereby providing the necessary thermal conductance between the cryocooler and the interface sleeve. The result is a relatively small temperature difference between the interface sleeve and the cryocooler during cooling of the superconducting magnets.

Abstract: A sleeve assembly for reducing the thermal conduction heat load from the bellows penetration tube to the heliumvessel of a superconducting magnet assembly. The sleeve assembly is designed to force helium boil-off gas to flow in intimate contact with the bellows convolutions. The helium boil-off gas thereby intercepts or removes a portion of the heat that would normally be conducted from the bellows convolutions to the helium vessel. The sleeve assembly consists of a circular cylindrical rolled tube made of laminated thermosetting material. The outer diameter of the tube is wrapped with tape in a helical pattern. The diameter of the sleeve and the thickness of the tape wrapping are selected so that the outer circumferential surface of the helically wrapped tape abuts the inner diameter of the bellows. The sleeve is fabricated with a relatively small thickness to minimize thermal con-duction load.

Abstract: A power coupling assembly for superconducting magnets includes a conduit with insulating tubes around each power lead, with the tubing passing through a plug at the upper end of the conduit and extending only part way to the lower end. Cryogen gas flowing from the magnet chamber into the conduit is forced to flow through the multiple tubes to cool the leads.

Abstract: A flexible castellated joint is included in the shim lead assembly electrically connecting the cryostat pressure vessel and the outer vacuum vessel in a superconducting magnet to accommodate relative motion between the two vessels during transportation of the superconducting magnet.

Abstract: An adjustable alignment assembly for a cryogen venting system for a superconducting magnet including a radially adjustable floating flange connection with a cryogenic seal to enable precise alignment of the cryostat vent pipe with the ceiling vent pipe of the room in which the superconducting magnet is installed.

Abstract: Power couplings are provided from outside the shell of a superconducting magnet through the intervening space and through the cryogen pressure vessel to the magnet coils within the vessel. The multi-pin shim magnet connector is replaceable without cutting the vessel open and the shim and main magnet main coil connectors include central apertures through which cryogen boil-off gas is flowed before venting to cool the connectors and reduce boil-off.

Abstract: Apparatus for reducing heat leakage into the interior of a liquid cryogen-holding vessel from the sealed well through which the vessel is accessed. An actively cooled heat sink in the well transfers heat to low temperature cryogen vapor venting from this vessel to the external environment.

Abstract: The device is provided for detachably coupling a power source to a lead pin of the superconducting magnet, the magnet being located in a cryostat using helium and the lead pin being in the region of helium vapor. Device includes a split connector formed to engage the pin, an elongated rod joined to the connector in conductive relationship, and a torque tube positioned around the rod in rotatable relationship. The tube is rotated, a nut joined to the tube and positioned around split connector causes the connector to tightly grip the pin. The device is configured to direct a flow of helium vapor along a path which is proximate to the interface between the connector and pin, to remove heat from the interface and thereby reduce resistance to current flow across the interface.

Abstract: A power operated contact apparatus extends and retracts one or more electrical leads into and out of a cryostat for making and breaking, at a cryogenic temperature, electrical contacts with a superconductive circuit. A pair of rigid elongated leads extend into a cold space of the cryostat which is at or near a cryogenic temperature. A connector is fixed at the inner end of each lead for making electrical contact in the cold space with a mating connector of the superconductive circuit. A guide journals each lead for axial movement and seals against the leading using an elastomeric O-ring coated with a lubricious polymer. A foundation is attached and sealed to the cryostat and to the guide means so that the connector on the inner end of the lead is extendable into making electrical contact with the connector of the superconductive circuit in the cold space.