Abstract: A magnet system with a magnet arrangement (M), a working volume (V) and a pulse tube cooler (P) with magnetic regenerator material (r) is characterized in that a shielding (m) of magnetic material is provided which reduces the stray field of the magnet arrangement at the location of the magnetic regenerator material (r) and is characterized in that ?|{tilde over (m)}RegR|+|mMag?x|<?|mRegR|, wherein mMag is the dipole moment of the magnetic material of the shielding (m), ?? is the vibration amplitude of the magnetic material of the shielding (m), mReg is the amplitude of the dipole fluctuations of the magnetic regenerator material (r) in one cycle without magnetic shielding (m), {tilde over (m)}Reg is the amplitude of the dipole fluctuations of the magnetic regenerator material (r) in one cycle with magnetic shielding (m), and R is the average separation of the magnetic regenerator material (r) from the working volume (V).

Abstract: A superconducting machine includes a superconductive device and a vacuum enclosure containing and thermally insulating the superconductive device. A cold-trap is configured to condense gases generated within the vacuum enclosure, and a coolant circulation system is adapted to force flow of a cryogen to and from the superconductive device and the cold-trap. A cryogenic cooling system is configured to cool the cryogen in the coolant circulation system upstream of the superconductive device. A vacuum retention method, for a high-temperature superconductive HTS device, includes applying vacuum to the HTS device to thermally insulate the HTS device, condensing gases generated around the HTS device using a cold-trap, flowing a cryogen to and from the HTS device, and flowing the cryogen to and from the cold-trap.

Abstract: A cryogen pressure vessel assembly for a superconducting magnet comprises an inner former, an outer former, and an outer shell. The inner former has a plurality of superconducting magnet coils wound thereon, and the outer former has a plurality of bucking coils wound thereon. The inner former, the outer former, and the outer shell form a fluid boundary for a cryogen. In one aspect, a pressure face is formed on at least one of the coil formers, and a radial slot for receiving wires entering and exiting a coil is disposed in the pressure face. A plurality of wire clamps are positioned in the radial slot, with each wire clamp in the plurality of wire clamps including: a front face extending coplanar with the pressure face, a rear face opposite the front face, the rear face contacting a back surface of the radial slot, and a recess formed in the rear face, the recess forming a channel for passage of the wires.

Abstract: In a device for the re-condensation of low-boiling gases evaporating from a liquid gas container having a tubular neck in which a cold head of a cryo-generator is supported, the cold head includes a pulse tube with a heat exchanger and a cold area having an annular projection extending into an annular recess formed in a heat transfer ring mounted in the tubular neck in closely spaced relationship with the walls of the annular recess so as to provide a gas passage therethrough and permitting relative axial movement between the cold head and the liquid gas container.

Abstract: A system capable of pumping or mixing fluids using a rotating magnetic element or bearing levitated by a cold superconducting element is disclosed.

Abstract: A passive gas-gap heat switch for use with a multi-stage continuous adiabatic demagnetization refrigerator (ADR). The passive gas-gap heat switch turns on automatically when the temperature of either side of the switch rises above a threshold value and turns off when the temperature on either side of the switch falls below this threshold value. One of the heat switches in this multistage process must be conductive in the 0.25° K to 0.3° K range. All of the heat switches must be capable of switching off in a short period of time (1-2 minutes), and when off to have a very low thermal conductance. This arrangement allows cyclic cooling cycles to be used without the need for separate heat switch controls.

Abstract: A system handles both reception signals collected via an antenna and transmission signals generated by a communication station for transmission via the antenna. The system includes a cryostat, a receive path carrying the reception signals and disposed in the cryostat, and a transmit path carrying the transmission signals. The receive path and the transmit path are coupled between the system and the antenna and between the system and the communication station. Accordingly, the receive path is duplexed with the transmit path such that the front-end system has a first single input/output connection for coupling the front-end system to the antenna and a second single input/output connection for coupling the front-end system to the communication station.

Abstract: A superconducting magnet assembly is described wherein the magnet cartridge is suspended within the vacuum chamber by a single support member extending from a wall of the vacuum chamber to the magnet cartridge. In one aspect, the support member includes a support tube and a joint attached to an end of the support tube. The joint is attached to the wall of the outer vacuum chamber, and provides at least one degree of freedom to the support tube relative to the wall. In another aspect, a joint is attached to an opposite end of the support tube, and is attached to the magnet cartridge for providing at least one degree of freedom to the support tube relative to the magnet cartridge. In another aspect, the support is constructed from one or more sections and the material choice is governed by the requirements for strength, stiffness, and thermal conductivity.

Abstract: The present invention is directed to a robot compatible crystal worksite suite comprising a unique dewar, a plurality of magazines, a plurality of cryo-pins (that mount crystals to be transferred from the dewar for crystallography study) adapted to be placed into the magazines and a programmed controller to provide the operational sequence necessary to remove the frozen mounted crystals from the dewar to an instrument or a goniometer for the x-ray diffraction of the crystals.

Abstract: MRI system 10 is provided. The MRI system 10 includes a magnet assembly 12. A first cryogen cooling fluid 20 is utilized to cool the magnet assembly 12. A first supply line 16 communicates the first cryogen cooling fluid 20 to the magnet assembly 12. A first return line 18 communicates the first cryogen cooling fluid 20 away from the magnet assembly 12. A blower assembly 22 is positioned between and in communication with the first supply line 16 and the first return line 18. A regenerative heat exchanger 36 is in communication with the first supply line 16 and the first return line 18. The regenerative heat exchanger 36 transfers thermal energy 29 from the first supply line 16 to the first return line 18. The regenerative heat exchanger 36 is positioned between the blower assembly 22 and the magnet assembly 12. A second supply line 28 transports a second cryogen fluid 26 through a pre-cooler assembly 24.

Abstract: A system and method for protecting a superconductor. The system may comprise a current sensor operable to detect a current flowing through the superconductor. The system may comprise a coolant temperature sensor operable to detect the temperature of a cryogenic coolant used to cool the superconductor to a superconductive state. The control circuit is operable to estimate the superconductor temperature based on the current flow and the coolant temperature. The system may also be operable to compare the estimated superconductor temperature to at least one threshold temperature and to initiate a corrective action when the superconductor temperature exceeds the at least one threshold temperature.

Abstract: A method for providing refrigeration to a refrigeration load such as superconducting equipment while reducing or eliminating potential two phase instability oscillations, wherein refrigeration condenses working fluid which is evaporated from the surface of a porous wick housed in an evaporator to generate a capillary pumping force to drive the condensed working fluid to the evaporator.

Abstract: A method and apparatus for providing cryogenic cooling to HTS devices, in particular those that are used in high-voltage electric power applications. The method involves pressurizing liquid cryogen to above one atmospheric pressure to improve its dielectric strength, while sub-cooling the liquid cryogen to below its saturation temperature in order to improve the performance of the HTS components of the device. An apparatus utilizing such a cooling method consists of a vessel that contains a pressurized gaseous cryogen region and a sub-cooled liquid cryogen bath, a liquid cryogen heating coupled with a gaseous cryogen venting scheme to maintain the pressure of the cryogen to a value in a range that corresponds to optimum dielectric strength of the liquid cryogen, and a cooling system that maintains the liquid cryogen at a temperature below its boiling point to improve the performance of HTS materials used in the device.

Abstract: Heater duty cycle (the active pressure control circuit) in recondensing superconducting magnet systems is monitored to determine total thermal system performance, to minimize non-zero boil-off operation, and to reduce maintenance costs. Undesirable conditions, such as a degrading cold head, plumbing leaks, and so forth, may be detected earlier by monitoring heater duty cycle. Appropriate service intervals may be determined and cryogen or helium losses may be reduced. The technique provides earliest possible identification of failures related to such variables, as well as, facilitates isolation of the root cause of the problem. Monitoring of heater duty cycle (energization time) offers advantages over the traditional approach of monitoring or alarming on low level in the cryogen (helium) vessel. The technique may provide for relying on observation of the effects of reduced cooling capacity, such as abnormal heater duty cycle, early enough in the failure cycle to prevent helium loss and equipment damage.

Abstract: A cryostat (1), having a cryostat chamber (2) in which a microtome for cutting frozen specimens is arranged, is described. An illumination device (4) for illuminating the cryostat chamber (2) is provided, the illumination device (4) comprising at least one LED (5).

Abstract: A cryostat configuration for keeping liquid helium, comprising an outer jacket (2) accommodating a helium container (5), a neck pipe (3) which is filled with gaseous helium during operation, and a refrigerator (1; 1b), wherein the outer jacket (2), the helium container (5) and the neck pipe (3) delimit an evacuated chamber (9) which surrounds the helium container (5); and wherein the refrigerator (1; 1b) has a cooling finger (4) which has a condensation body (15; 15b) in the region of the lower end of the neck pipe (3), is characterized in that the condensation body (15; 15b) is partially surrounded by a condensation chamber (16; 16b) which has a first lower opening (17) to permit draining of liquid helium, and a second opening which communicates with a lower end of a gas supply pipe (18), wherein the upper end of the gas supply pipe (18) terminates in the region of the upper end of the neck pipe (3). This improves the thermal properties of the cryostat configuration.

Abstract: A cryogenic chamber comprising an outer vacuum vessel (9), an inner cryogen vessel (11), a turret (40) housing a neck tube (8) itself providing external access to the inner cryogen vessel (11), and a pulse tube refrigerator (20) itself comprising at least one pulse tube and at least one regenerator tube. The pulse tube refrigerator is located within a vacuum contained between the outer vacuum vessel (9) and the inner cryogen vessel (11) and the pulse tube refrigerator (20) and the neck tube (8) share a single turret (40). The cooling stage(s) (6, 7) of the pulse tube refrigerator (20) is/are rigidly mechanically connected to the neck tube (8) by highly conductive thermal links. The pulse tube(s) and regenerator tube(s) are displaced away from the neck tube and from each other.

Abstract: An apparatus for measuring electromagnetic characteristics includes a sample rod with a sample fixed to a lower part thereof, a helium 3 refrigerator, in which the sample rod is inserted, having a main pipe that forms around the sample rod a space that is cooled by helium 3, a device for supplying helium 3 to the helium 3 refrigerator, an inner tube portion, into which the main pipe is inserted, that supports at an upper part thereof the refrigerator, an outer tube that cools an outer periphery of the inner tube with helium, a liquid helium container that supplies liquid helium to the outer tube, and a device for measuring the electromagnetic characteristics of the sample.

Abstract: Within upper and lower cryostats for a super conducting magnet level sensors which measure respective amounts of liquid helium therein are assembled and are connected to a measuring circuit. When a control signal of a computer is provided to the measurement circuit via a sequencer, the measurement circuit performs automatic measurement of a remaining amount of liquid helium and the measured data is transferred to the computer. The computer records the measured data as well as performs computation processing thereof and causes a display unit to display the processing result as an effective management parameter of the liquid helium. Thereby, an open type MRI apparatus using a super conducting magnet with liquid helium monitoring system which is suitable for maintenance and management of liquid helium for the super conducting magnet can be provided.

Abstract: The device comprises a monobloc subassembly (1) of cast stainless steel comprising a principal portion in the form of a disc (4) mounted on a collar (2) of the reservoir (3) and defining at least two channels (8, 9) for the passage of fluid, typically for filling, communication with the atmosphere, and withdrawal of liquid and gaseous phases reheated by atmospheric reheaters (23; 30) for the supply (31) of a controlled gaseous flow. Application particularly to cryogenic reservoirs for medical oxygen for oxygen therapy.

Abstract: An improved cryogenic fluid delivery system is disclosed that employs a closed microporous tube as a transfer conduit coupled to the outlet of a cryogenic fluid container, such as a Dewar. The microporous transfer conduit preferentially draws liquid through its microporous wall structure, simultaneously filtering impurities from the fluid.

Abstract: A superconducting machine includes a superconductive device and a vacuum enclosure containing and thermally insulating the superconductive device. A cold-trap is configured to condense gases generated within the vacuum enclosure, and a coolant circulation system is adapted to force flow of a cryogen to and from the superconductive device and the cold-trap. A cryogenic cooling system is configured to cool the cryogen in the coolant circulation system upstream of the superconductive device. A vacuum retention method, for a high-temperature superconductive HTS device, includes applying vacuum to the HTS device to thermally insulate the HTS device, condensing gases generated around the HTS device using a cold-trap, flowing a cryogen to and from the HTS device, and flowing the cryogen to and from the cold-trap.

Abstract: A cryostat having a connecting branch which is connected to a coolant chamber and is open on the end side. The connecting branch expands from an inside diameter to an outside diameter.

Abstract: Cryostat having a connecting branch which is connected to a cooling chamber and is open on the end side, raised parts and/or depressions increasing the wall surface being provided on at least part of the inner wall of the connecting branch.

Abstract: An ion beam producing device employing a refrigeration system to provide the cooling for a superconducting compression magnet at a trap core of an electron beam ion trap (EBIT) without the use of cryogenic liquid gases. The elimination of cryogenic cooling gases, such as liquid helium, is effectuated by the incorporation of cryo-refrigerators having highly thermally conductive cryo-heads, and a super-conducting, solid lead arrangement for energizing the compression magnet, the leads producing little or no heat within the cold shield. The reduction or elimination of use of liquid cooling-gases significantly reduces the size and operating cost of the electron beam source/trap system. A magnetic field line guide-field reduces magnet field-line interference otherwise risked by the reduction in size of the electron beam device.

Abstract: Effect of vibration of a refrigerator on a superconducting coil is reduced to reduce disturbance in an image. A coolant tank for supplying a coolant to coil containers is provided separately from the coil containers, and the refrigerator is placed in the coolant tank, and a coolant circulation passage connects between the coolant tank and the coil containers.

Abstract: A cryostat configuration for keeping liquid helium, comprising an outer jacket (2) accommodating a helium container (5), a neck pipe (3) which is filled with gaseous helium during operation, and a refrigerator (1; 1b), wherein the outer jacket (2), the helium container (5) and the neck pipe (3) delimit an evacuated chamber (9) which surrounds the helium container (5); and wherein the refrigerator (1; 1b) has a cooling finger (4) which has a condensation body (15; 15b) in the region of the lower end of the neck pipe (3), is characterized in that the condensation body (15; 15b) is partially surrounded by a condensation chamber (16; 16b) which has a first lower opening (17) to permit draining of liquid helium, and a second opening which communicates with a lower end of a gas supply pipe (18), wherein the upper end of the gas supply pipe (18) terminates in the region of the upper end of the neck pipe (3). This improves the thermal properties of the cryostat configuration.

Abstract: Effect of vibration of a refrigerator on a superconducting coil is reduced to reduce disturbance in an image. A coolant tank for supplying a coolant to coil containers is provided separately from the coil containers, and the refrigerator is placed in the coolant tank, and a coolant circulation passage connects between the coolant tank and the coil containers.

Abstract: A heat exchange method and apparatus having a cooled fluid flowing in contact with a first surface of a heat exchange wall and a cooling fluid flowing in contact with a second surface of the wall. At least one temperature sensor is located to directly monitor the temperature of the first surface. Flow of the cooling fluid is throttled when the temperature of the first surface drops at least 50 degrees below the freezing temperature of the cooled fluid.

Abstract: In a superconducting current limiter 1, in the limiting state pressure waves which may damage the superconductor are produced as a result of the evaporation of cooling liquid. According to the invention, the current limiter is not immersed in a cooling liquid, but rather is brought into thermal contact with a cooling fluid 22 which does not undergo a phase transition at over the operating temperature and therefore does not evaporate in the limiting state. A refrigeration reservoir 21, which may be the condensed phase of a gaseous cooling fluid or a cryogenic cooler, determines the operating temperature of the current limiter. One advantage is that it is now possible for a plurality of plate-like current-limiter modules 10, 10′ of unlimited size to be arranged next to one another in the cooling fluid 22.

Abstract: The current invention provides, in some embodiments, superconducting cryostat apparatuses, and methods for containing a coolant within the apparatuses and for cooling the apparatuses. The superconducting apparatuses provided by the invention include a self-contained supply of a coolant medium, which can be provided in the form of a pressurized gas. The mass of the coolant medium contained in the apparatus is conserved during operation of the apparatus. The superconducting cryostat apparatuses provided by the invention can be configured, in some embodiments, to eliminate the need for sources of external cooling during operation. The superconducting cryostat apparatuses provided by the invention can be cooled by supplying one or more sealable containers within the apparatuses with a quantity of cooling medium in gaseous form, and sealing the sealable containers.

Abstract: Viable biological material is cryogenically preserved (cryopreservation) by immersing the material in a tank of cooling fluid, and circulating the cooling fluid past the material at a substantially constant predetermined velocity and temperature to freeze the material. The material may either be directly plunged into the cooling fluid without preparation, or chemically prepared prior to freezing. A method according to the present invention freezes the biologic material quickly enough to avoid the formation of ice crystals within cell structures (vitrification) and allows the samples to maintain anatomical structure and remain biochemically active after thaw. The temperature of the cooling fluid is preferably between −20 degrees centigrade and −30 degrees centigrade, which is warm enough to minimize the formation of stress fractures and other artefacts in cell membranes due to thermal changes.

Abstract: A reaction vessel system includes a reaction vessel, a cooling unit functionally connected to the vessel to impart controlled cooling thereto; a heating unit functionally connected to the vessel to impart controlled heating thereto; and control means connected to the cooling unit and the heating unit for programmable automatic control of the cooling unit to control at least one of on/off flow and rate of flow, and to control at least one of on/off heating and rate of heating, including a programmable device. The cooling unit includes a cooling element in proximity to the vessel with at least one inlet port for injection of a phase change coolant, a heat absorbent area and at least one outlet port for removal of the phase change coolant. This is an injector for injecting the coolant in liquid form via the inlet port to the cooling element.

Abstract: The invention relates to a device for thermally stabilizing an object (20) to be cooled to a temperature of the order of 6 to 25 K by circulating a fluid, characterized in that it comprises:

Abstract: A thermal link assembly provides thermal connection between a first thermally conductive part to which it is secured, and a second thermally conductive part which is generally disk-shaped and has a peripheral cylindrical surface. The thermal link assembly includes an annular ring made of thermally conductive material, generally in a shape of a revolution with respect to an axis, including an annular base portion to be secured to the first part and a series of contact tongues arranged along the base portion. Each contact tongue has a stem and a head. The stem has i) a longitudinal axis extending generally parallel to the axis of the annular ring, ii) a first longitudinal end connected to the base portion, and iii) a second longitudinal end connected to the head. The head has a contact surface to be in contact with the peripheral cylindrical surface of the second part.

Abstract: According to this invention, a magnetic sensor (1) for measuring a magnetic field distribution of a measurement target S by using a SQUID (2) is characterized by including a storing portion (10) with an interior held in a vacuum state to store the SQUID (2), and a substantially needle-like flux introducing member (30) made of a high-permeability material to guide a magnetic flux from the measurement target (S) to the SQUID (2), wherein the flux introducing member (30) has one end (30a) located in the storing portion (10) to be away from the SQUID (2) and the other end (30b) located outside the storing portion (10).

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: An apparatus for measuring electromagnetic characteristics includes a sample rod with a sample fixed to a lower part thereof, a helium 3 refrigerator, in which the sample rod is inserted, having a main pipe that forms around the sample rod a space that is cooled by helium 3, a device for supplying helium 3 to the helium 3 refrigerator, an inner tube portion, into which the main pipe is inserted, that supports at an upper part thereof the refrigerator, an outer tube that cools an outer periphery of the inner tube with helium, a liquid helium container that supplies liquid helium to the outer tube, and a device for measuring the electromagnetic characteristics of the sample.

Abstract: Cryostat having a connecting branch which is connected to a cooling chamber and is open on the end side, raised parts and/or depressions increasing the wall surface being provided on at least part of the inner wall of the connecting branch.

Abstract: A liquid nitrogen cooling assembly incorporating a liquid detector which feeds back to control the nitrogen supply is disclosed. A pressure-controlled nitrogen source (e.g., a dewar) feeds liquid nitrogen to a heat exchanger mounted to a differential scanning calorimetry (DSC) cell. The DSC cell is cooled as liquid nitrogen in the heat exchanger contacting the cell is vaporized into nitrogen gas. The exhaust (nitrogen gas and, occasionally, nitrogen liquid) is fed to a liquid detection/evaporator assembly. If liquid nitrogen is detected in the exhaust by the liquid detection/evaporator assembly, an indication is fed back using a liquid detection feedback loop to a pressure control device. The pressure control device reduces the amount of pressure on the nitrogen source in order to eliminate liquid in the exhaust. When there is liquid in the exhaust, the liquid detection/evaporator assembly also collects and vaporizes the exhaust liquid so that it can be properly vented to atmosphere in gas form.

Abstract: A thermal link assembly provides thermal connection between first and second thermally conductive parts. The thermal link assembly is adapted for securing to the first part. The second part is generally disk-shaped and has a peripheral cylindrical surface. The thermal link assembly includes an annular ring made of thermally conductive material. The annular ring is generally in a shape of revolution with respect to an axis. The annular ring includes an annular base portion to be secured to the first part and a series of contact tongues arranged along the base portion. Each contact tongue has a stem and a head. The stem has i) a longitudinal axis extending generally parallel to the axis of the annular ring, ii) a first longitudinal end connected to the base portion, and iii) a second longitudinal end connected to the head. The head has a contact surface to be in contact with the peripheral cylindrical surface of the second part.

Abstract: Methods of cooling an object are presented, the methods comprising contacting a heat transfer fluid with a liquid cryogen to form a precooled, substantially pure heat transfer fluid, and contacting the object with the precooled substantially pure heat transfer fluid to form a cooled object and a recycle flow of the heat transfer fluid. The heat transfer fluid consists essentially of a compound selected from the group consisting of substantially pure hydrogen, substantially pure helium, substantially pure argon, substantially pure nitrogen, and substantially pure carbon dioxide. Each of the contacting steps may be either direct contact, indirect contact, or combinations thereof.

Abstract: An improved dewar design that accelerates the manufacturing process of a dewar. In a preferred embodiment, the dewar includes an evacuation port that may be larger in size by a factor of ten over the size of evacuation ports of conventional dewars. The oversized evacuation port, however, does not result in an increase in the overall size or profile of the dewar. The dewar is evacuated and hermetically sealed using an re-usable evacuation tool.

Abstract: A method for assembling a thermal shield suspension assembly including a plurality of straps, wherein the straps are arranged in an alternately cross hatch arrangement such that a plurality of first straps extend at a first orientation with regards to the cryogenic vessel and a plurality of second straps extend at a second orientation with regards to the cryogenic vessel, and wherein the first orientation is different from the second orientation and each second strap is disposed between the adjacent first strap is provided, the method comprising securing the first strap including the tensioning block to a thermal shield flange and a cryogenic vessel flange and securing the second strap to the thermal shield flange and the cryogenic vessel flange.

Abstract: A minimal magnetic-field measurement Dewar vessel includes an inner container which contains a superconducting device and cooling medium, a radiation shield which is composed of an electrical insulation substrate and a first and second plurality of thin line stripes provided on opposite surfaces of the electrical insulation substrate so that the first plurality of thin line stripes is electrically insulated from the second plurality of thin line stripes and provided in a high stripe dense state, an outer container, and a cooling apparatus. A width of one portion of at least one of the first and second plurality of thin line stripes arranged in one area of the radiation shield surrounding the superconducting device is smaller than a width of another portion of the at least one of the first and second plurality of thin line stripes arranged in another area of the radiation shield, respectively.

Abstract: An open flow cryostat for cooling a sample in use comprises a supply (1) for supplying a coolant, an outlet (2) for directing a flow of the coolant towards the sample, a supply line (3) for transporting coolant from the supply to the outlet and an isolation line (5) arranged to transport at least some of the coolant away from the outlet. The isolation line (5) is positioned in contact with at least a portion of the supply line (3) to thermally isolate the supply line (3) from the surroundings.

Abstract: This invention relates generally to cryogenic devices and, more particularly, to cryogenic devices of very small size based on superconducting elements, low thermal transmission interconnects and low dissipated power semiconductor

Abstract: A method and apparatus are set forth for transferring a cryogenic fluid. A polymeric, coaxial (i.e. “tube-in-tube” geometry) transfer line is utilized where a first portion of the cryogenic fluid flows through the inner tube while a second portion flows through an annulus between the inner tube and outer tube which annulus is at a lower pressure than the inside tube. In one embodiment, the inner tube is substantially non-porous and the transfer line is preceded by a flow control means to distribute at least part of the first and second portions of the cryogenic fluid to the inner tube and annulus respectively. In a second embodiment, the inner tube is porous with respect to both gas permeation and liquid permeation such that both a gaseous part and a liquid part of the first portion permeates into the annulus to form at least a part of the second portion.

Abstract: A dewar for SQUID is provided. In the dewar for SQUID, an amount of leak gas discharged from absorbent arranged in the upper portion higher than the liquid surface level of liquid helium is small even if the liquid surface level of the liquid helium is lowered.

Abstract: A method and apparatus for adjusting a device is provided in which characteristics of the device used at low temperature such as a high temperature superconductive filter are measured and adjusted without deterioration of the device. The device used at low temperature is disposed within an atmosphere of substitutional gas such as nitrogen and the like. The device is cooled by using cryogen, for example, liquid nitrogen, stored in a bath which is disposed in a glove box. The cryogen has a temperature near the temperature at which the device is used. The device is placed on a cooling stage which is partially soaked in the cryogen, thereby said device is cooled by the cryogen having a temperature near the temperature at which the device is used. Characteristics of the device are measured and adjusted while cooling the device by using the cryogen.