837 results about "High-temperature superconductivity" patented technology

A method of constructing a superconducting coil. The method includes embedding a plurality of heater elements throughout a superconducting coil. The heater elements are positioned according to a predetermined distribution and substantially in thermal contact with the coil for heating the coil in response to a quench condition. Other aspects of the invention involve an active protection circuit and a high temperature superconductor magnet that includes such an active protection circuit for internally dissipating stored magnetic energy in the event of a quench.

Methods and apparatuses for magnetic resonance imaging (MRI) and/or magnetic resonance spectroscopy comprising a superconducting main magnet operable to generate a uniform magnetic field in an examination region, at least one superconducting gradient field coil operable to apply a respective at least one magnetic field gradient within the examination region, and at least one RF coil that is operable to transmit and receive radio frequency signals to and from the examination region, and that is configured for cooling and comprises at least one of (i) a non-superconducting material that when cooled to a temperature below room temperature has a conductivity higher than that of copper at that temperature and (ii) a superconducting material. The main magnet, the gradient coils, and each of the at least one RF coil of a given system may each be implemented as high temperature superconductor materials.

A superconducting wire includes first and second superconducting layers disposed on one or more substrates in stacked relationship, the first superconducting layer comprising a high temperature superconducting oxide of a first composition and the second superconducting layer comprising a high temperature superconducting layer of a second composition, wherein the first and second compositions are different. The first superconductor layer optionally includes a high temperature superconductor composition selected to provide enhanced critical current (Ic(c)) in the presence of magnetic fields perpendicular to surface of the superconducting layer (H//c). The second superconductor layer optionally includes a high temperature superconductor composition selected to provide enhanced critical current (Ic) in the presence of magnetic fields parallel to surface of the superconducting layer (H//ab).

A high power high temperature superconductive circuit for use in various microwave devices including filters, dielectric resonator filters, multiplexers, transmission lines, delay lines, hybrids and beam-forming networks has thin gold films deposited either on a substrate or on top of the high temperature superconductive film. Alternatively, other metal films can be used or a plurality of dielectric films can be used or a dielectric constant gradient substrate can be used. The use of these materials in a part or parts of a microwave circuit reduces the current density in those parts compared to the level of current density if only high temperature superconductive film is used. This increases the power handling capability of the circuit.

The disclosed adaptor between cold junction of leading wire in heavy current of high-temperature superconductor and low resistance of superconducting transmission line includes structure: welding piles of high-temperature superconductor arranged in spaces to outer wall of support tube made from stainless steel in low thermal conductance; welding warm end in piles of high-temperature superconductor to transition piece of copper; through braze welding, cold end in piles is joined to NbTi/Cu superconducting line; cross winding NbTi/Cu line on inner copper tube sheathed inside outer copper tube; cooling superconducting line and copper connector by using liquid helium between inner and outer copper tubes. Features are: simple structure, suitable to connection under 20kA. In the invention, resistance of adaptor is lowered as 1.4-4.6n ohm. In supercritical quantity of helium flow 4g/s, all loss of 6 pieces of adaptor and 12 pieces of butt end of transmission line is less than 0.1Mpa.

A high temperature superconductor structure including: a substrate on which at least one buffer layer is deposited, a superconductor layer on the buffer layer, the superconducting layer composed of superconductor material that forms at least two substantially parallel superconductor filaments that continuously extend along the length of the substrate wherein at least two superconductor filaments are separated from each other by at least one insulating strip wherein the insulating strip continuously extends along the length of the substrate and is composed of insulating material with a resistivity greater than about 1 mΩcm. Also disclosed are methods of producing high temperature superconductors.

A HTS RF coil is disclosed having at least a factor of three improvement in the SNR over a comparable copper coil and at least a factor of six improvement in Q over a comparable copper coil. A commercially available HTS tape is formed into a loop. High-Q capacitors are soldered across the loop ends. The silver sheath covering the tape is removed through chemical etching. The coil is placed in a holder for mechanical support and protection and covered with a cover having through holes enabling the coolant to directly contact the HTS coil.

The invention discloses a measuring device of a high-temperature superconductive suspension tiny force. The measuring device comprises a vacuum cabin, a high-speed camera, a permanent magnet platform, a superconductor platform, a low temperature system, a calibration firing pin, a charge coupled device (CCD) laser speed detector and a floating mechanism; different firing calibration forces are provided through a calibration firing pin structure; then four configured CCD laser displacement sensors respectively obtain the vibration data along the vertical direction and the horizontal direction of a permanent magnet platform corresponding to different calibration forces, thereby forming an one-to-one corresponding relationship of the calibration force and the permanent magnet platform movement. When the tiny thrust of an electric thruster is acted on the permanent magnet platform, the CCD laser displacement sensor can obtain the vibration properties on the vertical and horizontal directions of the permanent magnet platform; then the tiny thrust of the electric thruster can be calculated according to the obtained one-to-one corresponding relationship of the calibration force and the permanent magnet platform movement.

A device used to test magnetic suspension performance of high temperature superconductive block consists of planar two-dimensional accurate positioner, support frame, sliding base, guiding screw, base cover, sliding jacket of guiding screw, guiding force and vertical force transducers, hanging plate, mechanism for hang sample and computer. It is featured as fixing electric cylinder on beam plate, connecting screw to sliding base by passing screw through beam plate in order to let said device detect out relation of vertical force or guiding force to displacement and time as well as magnetic rigidity of vertical force or guiding force.

The invention provides a ultra-high temperature superconductive cable insulation electric character tester, comprising a low temperature pressure thermal insulation controller provided with a cover board, a hole at the center of the cover board, an insulation sleeve penetrating through the hole, a vacuum connector mounted on the cover board, a connecting tube for filling liquid nitrogen and a connecting tube for adding pressure which are mounted on the cover board, a test electrode in the low temperature pressure insulation container, and a conductive bar in the insulation sleeve, of which the upper end is connected with high voltage and the lower end is connected with the high voltage end of the test electrode. The ultra-high temperature superconductive cable insulation electric character tester can improve the electric property of the insulation material of a high temperature superconductive cable, under low temperature liquid nitrogen temperature, having simple operation.

The present invention belongs to the field of technology of preparing rough base belt for high temperature superconductive coating and superconductive film. The preparation process of the ppi includes the following steps: discharge plasma sintering the mixture inside mold comprising Ni powder and W powder of purity over 99.9 % and granularity of 3-6 micron; maintaining at 800-1200 deg.c and 30-80 MPa for 0-10 min; cold rolling Ni-W plate at room temperature in the gate deformation of 5-15 % and total deformation over 97 %; re-crystallizing and annealing in the atmosphere of Ar with mixed H2 in 4 vol%, at temperature of 900-1300 deg.c and with annealing time of 0.5-3 hr. The said process is simple and fast, and the obtained polycrystalline Ni-W belt is used in depositing high temperature superconductive YBCO film.

The invention discloses a low temperature superconducting assembly with low joint resistance for a high temperature superconducting current lead cold end. The resistance of a 40-70kA high temperature superconducting super current lead of which the lower end is connected with a low temperature superconducting bus must be as low as 1 nano-ohm. A rectangular section niobium-titanium/copper superconducting wire or a high conductivity copper material and a paired box type joint structure connected with the superconducting bus are adopted in the low temperature superconducting assembly. Tests prove that the joint resistance of the low temperature superconducting assembly and a high temperature superconducting assembly can be as low as 0.5 nano-ohm, and the joint resistance of the superconducting bus is lower than 1 nano-ohm. The low temperature superconducting assembly is a middle result for developing super current leads of an international thermonuclear fusion test reactor and has the characteristics of novel conception and low manufacturing cost.

The decoupling of an array of two or more closely spaced high temperature superconductor sensors can be accomplished by introducing a capacitive decoupling circuit.

The use of a high temperature superconductor single loop or coil in the Q-damping circuit for a high temperature superconductor transmit, receive, or transmit and receive self-resonant coil in a nuclear quadrupole resonance system results in improved performance of the nuclear quadrupole resonance detection system.

The utility model relates to a quench detecting method of superconducting coils, which is characterized in detecting the temperature of superconducting coil winding at real time; a quench detecting value (temperature rising rate) is acquired by the means that the difference value on adjacent temperature in time is divided by time interval of temperature detection. By comparing the temperature rising rate with the threshold value of the temperature rising rate, the coil quench can be judged if the temperature rising rate exceeds the threshold valve. The determination method on the threshold value of the temperature rising rate is to detect the voltage and the temperature near the quench point at the same time in the process of detecting quench on the superconducting coil and to transform the temperature into the temperature rising rate. When the voltage rises to 1MuV/cm, coil quenches and the mean value of the temperature rising rate on both side of quench point is the threshold value of the temperature rising rate. The utility model is closer to the essence of physical phenomenon and has the advantages of fast detecting speed and high sensitivity. The utility model is applicable for low temperature superconducting (NbTi, Nb3Sn, MgB2) coils and high temperature superconducting (Bi2223, YBCO) coils.

The use of a bias controlled diode in the Q-damping circuit of a high temperature superconductor transmit, receive, or transmit and receive self-resonant coil in a nuclear quadrupole resonance detection system results in improved performance. The diode is operated with a forward bias such that the diode is resistive with a resistance of about 10 to about 1000 ohms.

High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La₂CuO₄) and a metal (La_1−xSr_xCuO₄), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, T_c may be either ˜15 K or ˜30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, T_c exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high T_c phases and to significantly enhance superconducting properties in other superconductors. The superconducting interface may be implemented, for example, in SIS tunnel junctions or a SuFET.

The invention relates to a design method used for transmitting DC high-temperature superconducting cable body coaxially and bidirectionally, belonging to the field of power system transmission and transformation; the design method comprises the steps as follows: according to the mechanical characteristic and the radius of enwinding framework of the superconducting strips, parameters of the superconducting cable body such as the enwinding helix angle and the enwinding pitch are determined; the magnetic field distribution of all layers of superconducting cable body are determined according to the operation current, thus determining the critical current on all layers of the cable; according to the critical current and the operation redundancy, iterative calculation is carried out for operation current and the magnetic field, thus finally gaining the critical current, best operation current, enwinding layer number and number of the cables. The designed superconducting cable body increases no enwinding process difficulty and achieves bidirectional transmission of DC current; the utilization ratio of the superconducting strip critical current reaches more than 90%; the quantity and low-temperature heat loss of the superconducting cable low-temperature container are respectively reduced by half. The design method has the advantages of large transmission capability, no loss, compact structure, certain current limiting capability, stable mechanical structure, self-shielding, no electromagnetic interference and the like.

The invention discloses a high-field superconducting magnet system with wide separation gaps. Superconducting coils of the system comprise a low-temperature superconducting coil (16) and a high-temperature superconducting coil (17). The superconducting coils are connected with a cold shield (3) and a flange (2) of a low-temperature container through a support pull rod (8), and are supported in the low-temperature container integrally. A thermoswitch (7) is connected with a primary cold head and a secondary cold head of a refrigerating machine (1), and the secondary cold head is connected with magnet-reinforcing support flanges (10) arranged at two ends of the low-temperature and high-temperature superconducting coils through a cold-guiding belt (5). The superconducting magnet system is provided with a horizontal room-temperature hole (12) and a vertical room-temperature hole (15); an outer cold shield (11) of the horizontal room-temperature hole is used for preventing heat radiation of the horizontal room-temperature hole (12) to the superconducting coils. A separation support frame (9) separates the low-temperature superconducting coil (16) and the high-temperature superconducting coil (17) into two parts, so when the superconducting magnets are integrated into a whole, a two-dimensional room-temperature space is contained in the integrated superconducting magnets.