228results about "Normal-superconductive switchable devices" patented technology

A sub-flux quantum generator includes an N-turn ring having a plurality of connected turns about a common aperture. The width of each respective turn in the N-turn ring exceeds the London penetration depth of a superconducting material used to make the respective turn. The generator includes a switching device configured to introduce a reversible localized break in the superconductivity of at least one turn in the N-turn ring. The generator includes a magnetism device configured to generate a magnetic field within the aperture of the N-turn ring. A method for biasing a superconducting structure that encompasses all or a portion of an N-turn ring. While a supercurrent is flowing through the N-turn ring, a quantized magnetic flux is introduced into the aperture of the N-turn ring using a reversible localized break in a turn in the ring. The quantized magnetic flux is trapped in the ring by removal of the localized break. The trapped flux biases the superconducting structure.

A magnet system for generating a magnetic field may include a superconducting magnet, a switch, and a heater element thermally coupled to the switch. The superconducting magnet is structured to generate magnetic fields, and the switch includes a non-inductive superconducting current carrying path connected in parallel to the superconducting magnet. In general, the switch is structured to only carry a level of current that is a portion of the current required to obtain a full field by the superconducting magnet.

An improved persistent current switch design and method of operation are disclosed. By way of example, a persistent current switch circuit comprises a heating element and a switch element located proximate to the heating element, the switch element being substantially formed from a material (by way of example only, titanium) which exhibits a superconducting temperature value below a superconducting temperature value exhibited by a material (by way of example only, aluminum) used to provide a connection to the switch element. The switch element is responsive to the heating element such that the heating element is used to control whether or not the switch element is in a superconducting state. The switch element may also have a folded geometry. Such persistent current switches exhibit low power and low inductance.

A superconducting nanowire avalanche photodetector (SNAP) with improved high-speed performance. An inductive element may be coupled in series with at least two parallel-coupled nanowires. The nanowires may number 5 or fewer, and may be superconducting and responsive to even a single photon. The series inductor may ensure current diverted from a photon-absorbing nanowire propagates to other nanowires and become amplified. The series inductance may be less than 10 times the nominal inductance per nanowire, and may also be larger than a minimum inductance to avoid spurious outputs in response to a photon absorption. The series inductance may be configured to achieve a desired tradeoff between SNAP reset time and spurious outputs. For example, the series inductance may be configured achieve minimum reset time or maximum bias margin, subject to user-defined constraints. By appropriately configuring the series inductance, a systematic method of designing improved SNAPs may be provided.

A superconducting current limiting element has a parallel circuit including a first superconductor and a normal conductor connected in parallel, and a second superconductor connected in series to the parallel circuit and having a critical current value higher than that of the first superconductor. Further, at least one of the normal conductor and the first superconductor, and the second superconductor are disposed on the same insulating substrate.

A device (10) for a current limiter is described, the device (10) comprising: at least one coil assembly (12) adapted to carry a current, the coil assembly (12) comprising: a first coil (14), comprising a first superconducting element, adapted to carry a first portion of said current, and a second coil (16), comprising a second superconducting element, adapted to carry a second portion of said current, wherein said first and second coils (14, 16) are arranged such that, when said first and second superconducting elements are each in a superconducting state and said coil assembly (12) carries said current, a magnetic field generated by said first portion of said current in said first coil (14) is substantially cancelled by a magnetic field generated by said second portion of said current in said second coil (16); and wherein said device is adapted such that, in use, the first superconducting element carries a higher proportion of said current than the second superconducting element. The device may be used in a superconducting fault current limiter to provide a low inductance during normal operation and a rapid and even quench under fault current conditions.

A superconducting switch is provided in which the structural strength of the superconducting switch is kept, and thermal efficiency between a superconducting film and a heater is high when an ON state (superconducting state) and an OFF state (normal conducting state) of the superconducting switch are switched. The superconducting switch includes a substrate, a heater for generating heat by energization, a conductive film, and a MgB2 film evaporated on the conductive film. The heater, the conductive film and the MgB2 film are laminated in this order on one surface of the substrate.

A single-photon detector includes a superconductor strip biased near its critical current. The superconductor strip provides a discernible output signal upon absorption of a single incident photon. In one example, the superconductor is a strip of NbN (niobium nitride). In another example, the superconductor strip meanders to increase its probability of receiving a photon from a light source. The single-photon detector is suitable for a variety of applications including free-space and satellite communications, quantum communications, quantum cryptography, weak luminescence, and semiconductor device testing.

In one embodiment, the invention is a hybrid superconducting-magnetic memory cell and array. One embodiment of a memory cell includes a magnetoresistive element and at least one superconducting element wired in parallel with the magnetoresistive element. In a further embodiment, memory cells of the disclosed configuration are arranged to form a memory array.

The present disclosure generally relates to a superconducting power grid having one or more AC / DC converters. The superconducting grid may further include one or more pairs of superconducting DC cables connecting each AC / DC converter. Each pair of superconducting DC cables may include a first positive polarity cable and a first negative polarity cable. The grid may also include at least one switching device configured to operatively connect at least one of the first and second AC / DC converters with at least one of the pairs of superconducting DC cables, the switching device further configured to adjust the polarity of at least one of the polarity cables. Other embodiments and implementations are also within the scope of the present disclosure.

A superconducting electrical cable system is configured to be included within a utility power grid. The superconducting electrical cable system includes a superconducting electrical path interconnected between a first and a second node within the utility power grid. A non-superconducting electrical path is interconnected between the first and second nodes within the utility power grid. The superconducting electrical path and the non-superconducting electrical path are electrically connected in parallel. The superconducting electrical path has a lower series impedance, when operated below a critical current level, than the non-superconducting electrical path. The superconducting electrical path has a higher series impedance, when operated at or above the critical current level, than the non-superconductor electrical path.

A superconducting transformer system is configured to be included within a utility power grid having a known fault current level. The superconducting transformer system includes a non-superconducting transformer interconnected between a first node and a second node of the utility power grid. A superconducting transformer is interconnected between the first node and the second node of the utility power grid. The superconducting transformer and the non-superconducting transformer are electrically connected in parallel. The superconducting transformer has a lower series impedance than the non-superconducting transformer when the superconducting transformer is operated below a critical current level and a critical temperature. The superconducting transformer is configured to have a series impedance that is at least N times the series impedance of the non-superconducting transformer when the superconducting transformer is operated at or above one or more of the critical current level and the critical temperature. N is greater than 1 and is selected to attenuate, in conjunction with an impedance of the non-superconducting transformer, the known fault current level by at least 10%.

A superconducting electrical cable system is configured to be included within a utility power grid having a known fault current level. The superconducting electrical cable system includes a non-superconducting electrical path interconnected between a first node and a second node of the utility power grid. A superconducting electrical path is interconnected between the first node and the second node of the utility power grid. The superconducting electrical path and the non-superconducting electrical path are electrically connected in parallel, and the superconducting electrical path has a lower series impedance than the non-superconducting electrical path when the superconducting electrical path is operated below a critical current level and a critical temperature. The superconducting electrical path is configured to have a series impedance that is at least N times the series impedance of the non-superconducting electrical path when the superconducting electrical path is operated at or above one or more of the critical current level and the superconductor critical temperature. N is greater than 1 and is selected to attenuate, in conjunction with an impedance of the non-superconducting electrical path, the known fault current level by at least 10%.

A superconducting current limiting device (30) comprising: an interconnected high magnetic permeability structure including a central core (50) interconnected to at least a first and second arm (31, 32) branching off therefrom; a superconductive coil (33, 34) surrounding the central core for biasing the central core; a first alternating current coil (36, 37) surrounding the first arm and interconnected to an alternating current source; a second alternating current coil (38, 39) surrounding a second arm and interconnected to an alternating current load; the first and second alternating current coils being magnetically coupled to the central core wherein the device operates so as to limit the current passing through the device upon the occurrence of a fault condition in the load.

A single trigger / shunt coil is utilized for combined induced magnetic field triggering and shunt impedance. The single coil connected in parallel with the high temperature superconducting element, is designed to generate a circulating current in the parallel circuit during normal operation to aid triggering the high temperature superconducting element to quench in the event of a fault. The circulating current is generated by an induced voltage in the coil, when the system current flows through the high temperature superconducting element.

A cryogenically-cooled HTS cable is configured to be included within a utility power grid having a maximum fault current that would occur in the absence of the cryogenically-cooled HTS cable. The cryogenically-cooled HTS cable includes a continuous liquid cryogen coolant path for circulating a liquid cryogen. A continuously flexible arrangement of HTS wires has an impedance characteristic that attenuates the maximum fault current by at least 10%. The continuously flexible arrangement of HTS wires is configured to allow the cryogenically-cooled HTS cable to operate, during the occurrence of a maximum fault condition, with a maximum temperature rise within the HTS wires that is low enough to prevent the formation of gas bubbles within the liquid cryogen.

A conductor arrangement for a resistive switching element, has at least first and second conductor connections disposed in a mutual plane adjacent to each other and insulated against each other. The composite conductors each have two conductor parts extending parallel, and forming a bifilar construction. The conductor parts are constructed from at least one superconducting conductor band. The composite conductors are formed into a coil winding, wherein the windings thereof substantially extend in the manner of a spiral, and are insulated against each other by a spacer.

An electrical filter includes a dielectric substrate with inner and outer coils about a first region and inner and outer coils about a second region, a portion of cladding removed from wires that form the coils and coupled to electrically conductive traces on the dielectric substrate via a solder joint in a switching region. An apparatus to thermally couple a superconductive device to a metal carrier with a through-hole includes a first clamp and a vacuum pump. A composite magnetic shield for use at superconductive temperatures includes an inner layer with magnetic permeability of at least 50,000; and an outer layer with magnetic saturation field greater than 1.2 T, separated from the inner layer by an intermediate layer of dielectric. An apparatus to dissipate heat from a superconducting processor includes a metal carrier with a recess, a post that extends upwards from a base of the recess and a layer of adhesive on top of the post. Various cryogenic refrigeration systems are described.

A current-jump-control circuit including an abrupt metal-insulator phase transition device is proposed, and includes a source, the abrupt metal-insulator phase transition device and a resistive element. The abrupt metal-insulator phase transition device includes first and second electrodes connected to the source, and shows an abrupt metal-insulator phase transition characteristic of a current jump when an electric field is applied between the first electrode and the second electrode. The resistive element is connected between the source and the abrupt metal-insulator phase transition device to control a jump current flowing through the abrupt metal-insulator phase transition device. According to the above current control circuit, the abrupt metal-insulator phase transition device can be prevented from being failed due to a large amount of current and thus the current-jump-control circuit can be applied in various application fields.

A superconducting article is provided which incorporates an early quench detection facility. The superconducting article includes a first superconductive segment and a second superconductive segment, along with a magnetic field sensor(s). The magnetic field sensor(s) is disposed to monitor relative change in strength of a net magnetic field generated by a first current passing through the first superconductive segment and a second current passing through the second superconductive segment. A relative change in strength of the net magnetic field indicates degradation of a critical quench current of the first superconductive segment or the second superconductive segment, caused for example, by formation of one or more hot-spots or quench regions in the first or second superconductive segment. The indication of degradation is thus obtained prior to complete superconductive segment quenching.

A liquid nitrogen low-temperature system for a superconducting current limiter belongs to the field of low-temperature engineering and technique. The liquid nitrogen low-temperature system comprises a liquid nitrogen container, a liquid nitrogen valve, a liquid nitrogen refuel valve, a safety valve, a valve cap, a test Dewar, a thermal insulation layer, a rupture disk, a deflation valve, a flow meter, a vacuum measurement gauge, a pressure difference sensor, a pressure sensor, a support part, a pumping valve, a vacuum pump, a superconducting current limiter, a control circuit, a temperature sensor and a discharging air pipe. In the invention, the system adopts the liquid nitrogen as the cooling working medium; the superconducting current limiter for the test is placed in the test Dewar; switching between the superconducting state and superconducting loss state of the superconducting current limiter can be realized through the control circuit; and the pressure, pressure difference and temperature measured by the pressure sensor, the pressure difference sensor and the temperature sensor, and the quality flow of the gasified nitrogen in the superconducting loss state measured by the flow meter are inputted into a computer, so as to evaluate the refrigeration wastage of the low-temperature system of the superconducting current limiter, and study the influence of the bubbles exerted on the low-temperature system pressure intensity when superconducting current limiter is abnormal. The low-temperature system has the advantages of simple structure, good economical efficiency, and favorable safety.

The present invention provides a superconducting wire usable in a low magnetic field region of 2 T or lower and at a temperature of 4.2 K or lower and a connection structure and a connection method for permitting such a superconducting wire use. The present invention also provides a highly reliable device that uses a superconducting wire. A superconducting wire rod according to an embodiment of the present invention includes a plurality of superconducting metal filaments, which are embedded in a metallic matrix of a normal conductor. Each superconducting metal filament is provided with a barrier layer made of a metal that does not react with Sn at a temperature between 250° C. and 500° C. The barrier layer is preferably made of Ta, Mo, or Ta- or Mo-based alloy and 0.01 μm to 1 μm in thickness.

A persistent current switch in a superconducting magnet, includes: a winding part in which a superconducting wire is noninductively wound; a winding-heating heater provided around the winding part; a vessel provided around the winding part with a space; and an anti-convective material provided in the space between the vessel and the winding part.

A heat switch 570 is disclosed as well as a gradiometer having the heat switch. The heat switch is formed from a non-magnetic material such as a semi-conducting material. The semi-conducting material may be provided by way of a Hall effect device. The heat switches are arranged in the gradiometer on a circuit board 856. The circuit board 850 has conducting strips 856 which are connected to conducting strips on a sensor 71 by bridges 852. The heat switch 570 is connected on the opposite side of the circuit board 850 to the strips 856 and processing circuitry 859. A copper substrate 865 is provided on the same side of the circuit board as the heat switch 570 to conduct heat away from the heat switch 570 when the heat switch is closed.

A system and method for generating a magnetic field in a rotating machine. In one embodiment, a primary winding assembly is configured to generate a rotatable magnetic field. The assembly is connected to receive multiple signals of different phases to effect field rotation. A set of secondary windings is positioned for generation of current based on magnetic coupling during the field rotation. The secondary windings include conductor capable of supporting superconducting current flow. A rotatable machine includes a stator and a rotor winding coupled for rotation with respect to the stator. The secondary windings are formed in a circuit for providing superconducting current through the rotor winding.

A resistive superconducting current limiter, by using a magnetic field generating device separated from the circuit of the power system, the current of the power system cannot flow to the linear coil of the resistive superconducting fault current limiting device when the normal current flows to the power system. It is possible to strengthen the current of the superconducting device, prevent the heat generated on the linear coil, and eliminate the magnetic field generated by the linear coil when the normal current is applied to the power system, and it is possible to use not only the BISCCO-based superconducting device, but also the YBCO-based superconducting device. guide device. The current limiter includes: a superconducting fault current limiting module, which is composed of at least one superconducting fault current limiting device; a magnetic field application unit, which is installed in a circular shape to surround the periphery of the superconducting fault current limiting module, with for applying a magnetic field to the superconducting fault current limiting module; and a current transformer for contactlessly inducing a current converted from a current flowing on a circuit of a power system, thereby applying the induced current to the magnetic field applying unit.