9 results about "Persistent current" patented technology

A system and method are provided for resetting a qubit including a superconducting loop and a compound Josephson junction. A first bias magnetic flux is supplied to the superconducting loop. A second bias magnetic flux is supplied to the compound Josephson junction. Each of the first bias magnetic flux and the second bias magnetic flux is supplied such that a given excited state of the qubit is near the top of a potential barrier associated with the potential of the qubit. A continuous microwave signal having a frequency equal to the transition frequency between the other excited state of the qubit and the given excited state is generated.

A persistent current switch is disclosed for controlling, e.g. initiating, a persistent current in a superconductor loop. The persistent current switch comprises a piece of superconductor material that is part of the superconductor loop. Further, the persistent current switch comprises an illumination system that is configured to direct light onto the piece of superconductor material for influencing an electrical resistance of the piece of superconductor material. The illumination system is configured such that the light impinging on the piece of superconductor material substantially does not heat the piece of superconductor material.

The invention relates to a system for controlling a superconducting coil (6) with a magnetic persistent current switch (7). The magnetic persistent current switch (7) is used for switching the superconducting coil (6) between a persistent mode and a ramp mode, respectively. The system further comprises a heat exchanger (10) configured to disperse heat to a cryocooler (3), a loop tube (13) configured to enable flow of coolant to transfer thermal energy generated by the magnetic persistent current switch (7) to the heat exchanger (10), and a thermal switch (9) comprising a valve (14) integrated with the loop tube (13) between the magnetic persistent current switch (7) and the heat exchanger (10), the valve (14) comprising a valve body (15) with and inlet (16) and an outlet (17) with which the valve body (15) is connected to the loop tube (13), a movable shaft (18) which is arranged inside the valve body (15) and which comprises a permanent rod magnet (19), a latching arrangement (20) which comprises a permanent magnet (21), and a solenoid (22), wherein the shaft (18) is movable between a closed position in which the shaft (18) effects the closing of the inlet (16) or the outlet (17) of the valve body (15) and therefore no flow of coolant through the valve body is allowed, and an open position in which the inlet (16) and the outlet (17) of the valve body (15) are open and therefore flow of coolant through the valve body (15) is allowed, the solenoid (22) is arranged relative to the shaft (18) in such a way that by applying a current pulse with a first polarity to the solenoid (22) the shaft (18) is moved to the closed position, and by applying a current pulse with a second polarity to the solenoid (22), the second polarity being opposite to the first polarity, the shaft (18) is moved to the open position, and the latching arrangement (20) is arranged relative to the shaft (18) in such a way that the magnetic force acting from the permanent magnet (21) of the latching arrangement (20) to the permanent magnet (19) of the shaft (18) forces the shaft (18) to stay in the closed position or in the open position, respectively, as long as no current pulse is applied to the solenoid (22) for switching the shaft (18) from the closed position to the open position or vice versa, respectively. In this way, a cooling system is provided that allows the temperature of the magnet persistent current switch (7) to rise and fall as desired within a short period of time, without straining the cooling system for the superconducting coil (7).

An alternative approach to flux pumping in superconducting devices is described for fast and extremely precise tuning of the current during persistent mode operation. Rather than bringing in new flux from outside the circuit, the alternative approach stores a small flux in a tunable inductor (also referred to herein as a “flux bank”) at the initial point of powering. Flux can be transferred back and forth from this bank to the main coil by simply changing the inductance of the bank. This allows for fine and fast adjustments of the persistent current without the use of thermal switches found in other approaches (which limit the adjustment speed and accuracy).

Systems and methods are provided for resetting a qubit comprising a superconducting loop and a compound Josephson junction. A first bias flux is provided to the superconducting loop. A second bias flux is provided to the compound Josephson junction. Each of the first bias flux and the second bias flux are provided such that a given excited state of the qubit is near a top of a potential barrier associated with a potential of the qubit. A continuous microwave signal is generated having a frequency equal to a transition frequency between an other excited state of the qubit and the given excited state.

Hybrid wound rotor motor and generator with inductive feed and persistent current. In one or more examples, a system operating in a generator mode includes a cryogenic refrigerator to cool a superconducting coil. The system also includes a magnetic flux pump to provide magnetic flux to the superconducting coil. Additionally, the system includes a shaft of a prime mover to receive torque to rotate a rotor. Additionally, the system includes a superconducting coil to electrically interact with a main stator coil through a rotating magnetic field. Furthermore, the system includes a control stator coil to receive current from a controller and electrically interact with a non-superconducting coil. In one or more examples, a size, phase, and / or frequency of the rotating magnetic field of the superconducting coil and the non-superconducting coil is varied compared to a size, phase, and / or frequency of a magnetic field generated by the superconducting coil alone to control a size, phase, and / or frequency of an output voltage.

A persistent current switch and method for fast ramping of an MRI system is provided. The persistent current switch wire is distributed in at least one layer over a bobbin. Each of the layers of the persistent current switch wire is in contact with at least one thermally conductive cooling surface. The cooling surface cools the persistent current switch wire to the threshold temperature for a superconducting state. The method includes distributing the persistent current switch wire in at least one layer over a bobbin. Each of the layers of the persistent current switch wire is in contact with at least one thermally conductive cooling surface and the cooling surface cools the persistent current switch wire to a superconducting state.

A magnet continuous current switch (MPCS) includes a superconducting wire assembly (10) having a connection port (11) at its end, and forming a main LTS conductor path (12) of low-temperature superconducting material and a parallel HTS shunt (13) of high-temperature superconducting material. Compared to superconducting magnets with conventional low-temperature material MPCS, the time required from the start of the rising field to the magnet being operable is reduced.

The objective is to provide a superconducting magnetic flux pump and excitation experimental system having a volt-class DC voltage output. [Solution] The present invention relates to a superconducting flux pump and an excitation experimental system having a volt-class DC voltage output, belonging to the technical field of superconducting flux pumps. The superconducting flux pump uses a three-phase AC core and a DC bias core to form a magnetic coupling gap. When a three-phase AC current is supplied to the three-phase AC winding, magnetic flux is guided through the core, generating a traveling wave magnetic field in the magnetic coupling gap. The magnetic field generated by the DC bias winding is also guided through the core, generating a DC bias magnetic field in the magnetic coupling gap. The traveling wave magnetic field and the DC bias magnetic field are superimposed to generate a biased traveling wave magnetic field in the magnetic coupling gap, which acts on the superconducting stator in the magnetic coupling gap, thereby generating a DC voltage output. The present invention makes it possible to achieve a volt-class DC voltage output with a superconducting flux pump, significantly reducing the power supply cost of high-temperature superconducting magnets, contributing to a reduction in the burden on the cooling system, and enabling rapid charging of the superconducting coil and operation in persistent current mode.