224results 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.

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 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.

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 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.

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 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 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.