78 results about "Persistent current" patented technology

Magnetic levitation methods and apparatus use arrays of vehicle magnets to provide three forces: suspension, guidance and propulsion. The magnets, which can be permanent magnets or superconducting magnets operating in the persistent current mode, have associated control coils that allow the magnets to provide a controllable attractive force to a laminated steel rail. The control coils adjust the gap between the magnets and the rails so as to be in stable equilibrium without requiring significant power dissipation in the control coils. These same magnets and steel rails also provide lateral guidance to keep the vehicle on the track and steer the vehicle on turns. The suspension control coils can provide lateral damping by means of offset magnets in the suspension arrays. Windings in transverse slots in the steel rails are excited with currents that react against the field produced by the vehicle magnets to create vehicle propulsion. The magnet size is adjusted to provide negligible cogging force even when there are as few as three winding slots per wavelength along the rail. Means are used to mitigate end effects so that a multiplicity of magnet pods can be used to support the vehicle.

Method and apparatus for providing thermal protection for actuators used in haptic feedback interface devices. An average energy in the actuator over a predetermined period of time is determined, and the maximum allowable current level in the actuator is reduced if the average energy is determined to exceed a predetermined warning energy level. The maximum allowable current level can be reduced to a sustainable current level if the average energy reaches a maximum energy level allowed, and the maximum allowable current level in the actuator can be raised if the average energy is determined to be below the predetermined warning energy level. Preferably, the maximum allowable current level is reduced smoothly as a ramp function.

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.

Quantum annealing may include applying and gradually removing disorder terms to qubits of a quantum processor, for example superconducting flux qubits of a superconducting quantum processor. A problem Hamiltonian may be established by applying control signals to the qubits, an evolution Hamiltonian established by applying disorder terms, and annealing by gradually removing the disorder terms. Change in persistent current in the qubits may be compensated. Multipliers may mediate coupling between various qubits and a global signal line, for example by applying respective scaling factors. Two global signal lines may be arranged in an interdigitated pattern to couple to respective qubits of a communicatively coupled pair of qubits. Pairs of qubits may be communicatively isolated and used to measure a response of one another to defined signals.

A compact sensor system integrates electric and magnetic field sensors to accurately measure, with a high level of sensitivity, electric and magnetic fields. The sensor system is self-contained so as to include a built-in power source, as well as data storage and / or transmission capability. The integrated sensor system also preferably includes a global positioning system (GPS) to provide timing and position information, a sensor unit that can determine the orientation and tilt of the sensor system, and self-calibrating structure which produces local electric and / or magnetic fields used to calibrate the sensor system following deployment. The system measures the electromagnetic signals produced by lightning and more has the capability to determine the direction and distance to a lightning event without input from sensors at other locations. Furthermore, the system can detect both conventional short-duration lightning events and also the less common, but more destructive, continuing current lightning.

Magnetic levitation methods and apparatus use arrays of vehicle magnets to provide three forces: suspension, guidance and propulsion. The magnets, which can be permanent magnets or superconducting magnets operating in the persistent current mode, have associated control coils that allow the magnets to provide a controllable attractive force to a laminated steel rail. The control coils adjust the gap between the magnets and the rails so as to be in stable equilibrium without requiring significant power dissipation in the control coils. These same magnets and steel rails also provide lateral guidance to keep the vehicle on the track and steer the vehicle on turns. The suspension control coils can provide lateral damping by means of offset magnets in the suspension arrays. Windings in transverse slots in the steel rails are excited with currents that react against the field produced by the vehicle magnets to create vehicle propulsion. The magnet size is adjusted to provide negligible cogging force even when there are as few as three winding slots per wavelength along the rail. Means are used to mitigate end effects so that a multiplicity of magnet pods can be used to support the vehicle.

A method for identifying a Na+ channel blocker, including providing a cell containing a Na+ channel, demonstrating both a transient and a persistent current. The cell includes a potassium (K+) channel and a Na / K ATPase (Na+ pump). A fluorescent dye is disposed into the well. The fluorescent dye is sensitive to change in cell membrane potential in order to enable optical measurement of cell membrane potential. A Na+ channel blocker, to be identified, is added to the well and a stimulating current is passed through the cell in an amount sufficient to generate an action potential before and after the addition of the Na+ channel blocker. Thereafter, a change in cell membrane potential is optically measured.

In a superconducting coil, a parallel conductor includes a plurality of superconducting wires bundled and wound in a coil. The superconducting wires have at least two connections therebetween. A current source connected to the superconducting wires to form a loop via the superconducting wires and the connection to supply a current in the loop when a quench is detected. A superconducting magnet includes the superconducting coil, a persistent current switch connected to the superconducting coil, and a quench detector configured to detect quench occurring in the superconducting coil.

Method and apparatus for providing thermal protection for actuators used in haptic feedback interface devices. An average energy in the actuator over a predetermined period of time is determined, and the maximum allowable current level in the actuator is reduced if the average energy is determined to exceed a predetermined warning energy level. The maximum allowable current level can be reduced to a sustainable current level if the average energy reaches a maximum energy level allowed, and the maximum allowable current level in the actuator can be raised if the average energy is determined to be below the predetermined warning energy level. Preferably, the maximum allowable current level is reduced smoothly as a ramp function.

An apparatus including a persistent current switch of a superconducting material which is electrically superconducting at a superconducting temperature and electrically resistive at a resistive mode temperature which is greater than the superconducting temperature. The apparatus further includes a first heat exchange element; a convective heat dissipation loop thermally coupling the persistent current switch to the first heat exchange element; a second heat exchange element spaced apart from the first heat exchange element; and a thermally conductive link thermally coupling the persistent current switch to the second heat exchange element. The first heat exchange element is disposed above the persistent current switch. The thermally conductive link may have a greater thermal conductivity at the superconducting temperature than at a second temperature which is greater than the superconducting temperature.

Disclosed is a method of splicing ReBCO high temperature superconductors (HTSs), which ensures excellent superconductivity after splicing. The method of splicing 2G ReBCO HTSs allows a superconductors-spliced assembly to exhibit excellent superconductivity by direct contact of high temperature superconducting layers of two strands of 2G ReBCO HTSs and solid state atoms diffusion pressurized splicing there between at a ReBCO below peritectic reaction temperature in a vacuum, and enables loss of superconductivity caused by loss of oxygen due to transport and out-diffusion of oxygen to atoms during splicing to be recovered through oxygenation annealing.

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.

The present invention relates to a radiographic imaging apparatus and a corresponding radiographic imaging method. The proposed apparatus comprises an X-ray source (20, 108) and a photon counting X-ray detector (40, 110). The X-ray source (20, 108) comprises a rotary X-ray anode (23) having a number of radial slits and a target layer provided on a surface of said rotary X-ray anode in between said radial slits for emitting X-ray radiation when hit by said electron beam. The said photon counting X-ray detector (40, 110) comprises a persistent current sensing and correction unit (70) for sensing a persistent output current in a blanking interval during which no X-ray radiation is emitted by said X-ray source and for using the sensed persistent output current to correct a detector signal in a subsequent measurement interval during which X-ray radiation is emitted by said X-ray source.

A superconducting magnet system includes resistive heaters and bidirectional diodes connected in series with each other installed in a superconducting coil protection circuit, and a diode is installed in a persistent current switch protection circuit.

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 solid-state quantum computing structure includes a dot of superconductive material, where the superconductor possesses a dominant order parameter with a non-zero angular momentum and a sub-dominant order parameter that can have any pairing symmetry. Alternately a solid-state quantum computing structure includes an anti-dot, which is a region in a superconductor where the order parameter is suppressed. In either embodiment of the invention, circulating persistent currents are generated via time-reversal symmetry breaking effects in the boundaries between superconducting and insulating materials. These effects cause the ground state for the supercurrent circulating near the qubit to be doubly degenerate, with two supercurrent ground states having distinct magnetic moments. These quantum states of the supercurrents store quantum information, which creates the basis of qubits for quantum computing. Writing to the qubits and universal single qubit operations may be performed via the application of magnetic fields. Read-out of the information may be performed using a SQUID microscope or a magnetic force microscope.

This invention provides a superconducting magnet apparatus capable of preventing or restraining the heat invading into the apparatus and reducing the refrigeration load of an external refrigerator, at the time of changeover of a switch in transiting to a persistent current mode, and capable of quick changeover operation. In the superconducting magnet apparatus of the present invention (1), in transiting to a persistent current mode, a thermal superconducting switch (41) placed in a low-temperature domain and a mechanical switch (42) placed in a mid-temperature domain are turned on. Since the mechanical switch (42) is placed in the mid-temperature domain, even if a heat load is generated through the drive mechanism (60), it is not necessary to cool the mechanical switch to an extremely low temperature. In short, heat generated at the contact point of the mechanical switch (42) and heat invasion through the drive mechanism (60) are applied not to the low-temperature domain, but to the mid-temperature domain, so that an external refrigerator can easily absorb the heat load and the capacity of the refrigerator can be reduced.

Quantum annealing may include applying and gradually removing disorder terms to qubits of a quantum processor, for example superconducting flux qubits of a superconducting quantum processor. A problem Hamiltonian may be established by applying control signals to the qubits, an evolution Hamiltonian established by applying disorder terms, and annealing by gradually removing the disorder terms. Change in persistent current in the qubits may be compensated. Multipliers may mediate coupling between various qubits and a global signal line, for example by applying respective scaling factors. Two global signal lines may be arranged in an interdigitated pattern to couple to respective qubits of a communicatively coupled pair of qubits. Pairs of qubits may be communicatively isolated and used to measure a response of one another to defined signals.

This invention provides a superconducting magnet apparatus capable of preventing or restraining the heat invading into the apparatus and reducing the refrigeration load of an external refrigerator, at the time of changeover of a switch in transiting to a persistent current mode, and capable of quick changeover operation. In the superconducting magnet apparatus of the present invention (1), in transiting to a persistent current mode, a thermal superconducting switch (41) placed in a low-temperature domain and a mechanical switch (42) placed in a mid-temperature domain are turned on. Since the mechanical switch (42) is placed in the mid-temperature domain, even if a heat load is generated through the drive mechanism (60), it is not necessary to cool the mechanical switch to an extremely low temperature. In short, heat generated at the contact point of the mechanical switch (42) and heat invasion through the drive mechanism (60) are applied not to the low-temperature domain, but to the mid-temperature domain, so that an external refrigerator can easily absorb the heat load and the capacity of the refrigerator can be reduced.

The active shield superconducting electromagnet apparatus includes: a main switching circuit in which first and second main coils, first and second shield coils, and a first superconducting persistent current switch are connected in series; a sub switching circuit in which a bypass circuit, in which a superconducting fault current limiter and a second superconducting persistent current switch are connected in series, are connected to a series circuit of the first main coil and the second main coil in parallel; a first closed circuit in which at least one of the first main coil and the first shield coil, and a first quench protection circuit are connected in series; and a second closed circuit in which one of the second main coil and the second shield coil, and a second quench protection circuit are connected in series.

The attenuation of a magnetic field during a permanent current mode operation is prevented, the generation of heat at a coupling portion between a permanent current switch and a superconducting coil is suppressed, and the increase of a superconducting coil cooling temperature in a current supply mode is minimized. A refrigerator cooling-type superconducting magnet (J) is comprised of a superconducting coil (2); a permanent current switch (1) which switches from a permanent current mode to a current supply mode; first and second extremely-low temperature refrigerators (3, 4) which cool the superconducting coil (2) and the permanent current switch (1), respectively; and a vacuum container (10) which stores cooling stages (31, 32, 41, 42) for the superconducting coil (2), the permanent current switch (1), and the first and second extremely-low temperature refrigerators (3, 4). The refrigerator cooling-type superconducting magnet (J) is comprised of a superconducting wire (5) for couplingthe superconducting coil (2) to the permanent current switch (1), and a superconducting bypass wire (6) electrically connected in parallel to the superconducting wire (5) in the longitudinal direction. The superconducting critical temperature of the superconducting bypass wire (6) is higher than the superconducting critical temperature of the permanent current switch (1).

An apparatus including an electrically conductive coil which produces a magnetic field when an electrical current passes therethrough; a selectively activated persistent current switch connected across the electrically conductive coil; a cryostat having the electrically conductive coil and the persistent current switch disposed therein; an energy dump; at least one sensor which detects an operating parameter of the apparatus and outputs at least one sensor signal in response thereto; and a magnet controller. The magnet controller receives the sensor signal(s) and in response thereto detects whether an operating fault (e.g. a power loss to the compressor of a cryocooler) exists in the apparatus, and when an operating fault is detected, connects the energy dump unit across the electrically conductive coil to transfer energy from the electrically conductive coil to the energy dump unit. The energy dump unit disperses the energy outside of the cryostat.

An apparatus includes an electrically conductive coil which produces a magnetic field when an electrical current passes therethrough; a selectively activated persistent current switch connected across the electrically conductive coil; a cryostat having the electrically conductive coil and the persistent current switch disposed therein; an energy dump; at least one sensor which detects an operating parameter of the apparatus and outputs at least one sensor signal in response thereto; and a magnet controller. The magnet controller receives the sensor signal(s) and in response thereto detects whether an operating fault (e.g. a power loss to the compressor of a cryocooler) exists in the apparatus, and when an operating fault is detected, connects the energy dump unit across the electrically conductive coil to transfer energy from the electrically conductive coil to the energy dump unit. The energy dump unit disperses the energy outside of the cryostat.

A switch can be used in conjunction with a superconducting current path to provide a more reliable circuit and system. The switch can be connected in parallel with a portion of the superconducting current path. In one embodiment, the switch may be connected in parallel with an entire superconducting element, such as a persistent current switch, a superconducting coil, or the like, or may be connected in parallel across only a portion of a superconducting element. A method of using the system is also disclosed.

The invention discloses an embedded energy collector based on respiratory movement, which comprises an energy converter. The energy converter is mainly formed of a movable linkage joint, a bistable-state piezoelectric metal sheet, a location guide rail and a package casing. The location guide rail is fixed on the package casing to be in slide fit with the movable linkage joint, the bistable-state piezoelectric metal sheet, two sides of the bistable-state piezoelectric metal sheet are respectively connected with the movable linkage joint, and the location guide rail and the package casing are arranged on two sides of the movable linkage joint. Two movable ends of the energy converter are fixed on two adjacent ribs. When a user breathes, gaps between ribs are led to be changeable by expansion and extraction of chest cavities to drive a cross linkage joint to enable the bistable-state piezoelectric metal sheet to generate continuous current periodically. The embedded energy collector based on respiratory movement can achieve permanent stable energy supply of embedded equipment in human chest cavities, and simultaneously is small in volume and capable of reducing body loads of patients and avoiding secondary operations for replacing batteries after the embedded equipment is embedded.

The embodiment of the invention relates to the technical field of a superconducting magnet energy charging power supply, and particularly discloses a permanent magnetic type superconducting magnet wireless energy charging power supply. The permanent magnetic type superconducting magnet wireless energy charging power supply comprises a permanent magnet, a power mechanism for driving the permanent magnet to take the circular motion around a rotating shaft, a superconducting stator capable of being cut by a magnetic field of the permanent magnet, and a superconducting coil forming a superconducting closed loop with the superconducting stator; and both the superconducting stator and the superconducting coil are in a superconducting state. According to the permanent magnetic type superconducting magnet wireless energy charging power supply disclosed by the invention, based on a novel vortex dynamics magnetizing principle, non-contact type energy charging can be implemented on a superconducting magnet, and the superconducting magnet is helped to operate in a persistent current mode; the device greatly reduces superconducting magnet power supply cost and operation energy consumption; and meanwhile, a current lead is avoided and a load of a refrigeration system is reduced.