Abstract: Quantum computing systems require methods to control energies of qubits and couplers for quantum operations. Flux biasing of qubits and quantum couplers is provided for a superconducting quantum computer using single-flux-quantum (SFQ) technology. This method is applicable to a wide range of superconducting qubit structures and couplers, including transmons, fluxoniums, flux qubits, phase qubits and other superconducting qubits. This method enables arbitrary-amplitude time-varying flux biasing of qubits and couplers, due to a sequence of high-speed SFQ pulses. Several preferred embodiments are disclosed which provide high-fidelity control of fast single-qubit and multi-qubit operations.

Abstract: A shield for a cryogenic chamber and a cryogenic chamber comprising a shield are described. In an example embodiment, a cryogenic chamber comprises an interior housing comprising housing walls that define an action chamber. The action chamber is configured to be cryogenically cooled to an action temperature. The cryogenic chamber further comprises an interior shield at least partially sandwiched within the housing walls. The interior shield is made of a first material that acts as a superconductor at the action temperature.

Abstract: A magnetic resonance system may include a magnetic resonance magnet and a storage container configured to accommodate the magnetic resonance magnet. The storage container may also contain an endothermic liquid. The magnetic resonance system may further include a ramping-down device configured to trigger releasing electric energy by the magnetic resonance magnet. The first ramping-down device may include an electric energy consumption device configured to consume at least a portion of the released electric energy by the magnetic resonance magnet.

Abstract: There is described a device for controlling an amount of current within a power distribution network by manipulating the amount of magnetic flux in the device and thus the impedance experienced by the power distribution network across the device. This is achieved by winding a plurality of coils about a magnetically permeable core and by providing the device with a magnetically permeable bridge element that is movable between a fully-open position at which the net magnetic flux generated in the core by alternating currents in each coil is zero, and a fully-closed position at which a net magnetic flux is present in the core.

Abstract: An examination system including a magnetic resonance scanner having a solenoid for generating a magnetic field, the solenoid surrounding an examination chamber is provided. In addition, a first X-ray source and a first X-ray detector are provided in the examination chamber.

Abstract: A magnetic resonance system may include a magnetic resonance magnet and a storage container configured to accommodate the magnetic resonance magnet. The storage container may also contain an endothermic liquid. The magnetic resonance system may further include a ramping-down device configured to trigger releasing electric energy by the magnetic resonance magnet. The first ramping-down device may include an electric energy consumption device configured to consume at least a portion of the released electric energy by the magnetic resonance magnet.

Abstract: An examination system including a magnetic resonance scanner having a solenoid for generating a magnetic field, the solenoid surrounding an examination chamber is provided. In addition, a first X-ray source and a first X-ray detector are provided in the examination chamber.

Abstract: A tunable qubit device includes a tunable qubit, the tunable qubit including a superconducting quantum interference device (SQUID) loop. The tunable qubit device further includes a superconducting loop inductively coupled to the SQUID loop, and a flux bias line inductively coupled to the superconducting loop. The superconducting loop includes a superconducting material having a critical temperature that is a lower temperature than a critical temperature of any superconducting material of the tunable qubit. In operation, the superconducting loop provides a persistent bias to the tunable qubit.

Abstract: A quench protection apparatus includes a number N of superconducting coils and a heater matrix. The number N of superconducting coils are electrically coupled in series. The heater matrix module includes the number N of heater units. The number N of heater units is electrically coupled in parallel with the number N of superconducting coils respectively. A number M of the heater units each includes at least the number N of heaters. Each superconducting coil is thermally coupled with at least one heater of each of the number M of the heater units. The number of N-M of the heater units each includes at least one heater. Each of the number M of superconducting coils correspondingly coupled with the number M of the heater units is thermally coupled with at least one heater of each of the number N-M of the heater units. A superconducting magnet system protected by above quench protection apparatus is also provided.

Abstract: An item of interconnection equipment for a high-voltage DC grid includes first and second terminals for connection to first and second lines of a high-voltage DC grid, a third terminal for connection to a local station or a line of the high-voltage grid, a node connected to the first to third terminals, a first superconductor current limiter and a first controlled switch connected in series between the first terminal and the node, a second superconductor current limiter and a second controlled switch connected in series between the second terminal and the node, a third superconductor current limiter and a third controlled switch connected in series between the third terminal and the node, and a current injector configured to inject an electrical current into the node.

Abstract: An adaptive passive quench propagation circuit in combination with a superconducting magnet having multiple superconducting coils electrically connected in series between a power supply terminal and a ground reference voltage terminal, has a superconducting switch arranged to electrically connect the power supply terminal and the ground reference voltage terminal to provide a closed-loop persistent superconducting circuit, multiple resistive heaters, each in thermal contact with one of the coils, a tapping point situated between two electrically adjacent coils, and a quench propagation circuit connected between the tapping point and a reference voltage.

Abstract: A superconducting magnet coil system with high resistance to quench events includes a first coil portion (1) with a first superconducting material and a second coil portion (2) with a second superconducting material. The first superconducting material has a higher critical temperature than the second superconducting material. The first and the second coil portions are bridged by a common quench protection element (6) and together with the quench protection element form a first loop. The magnet coil system also includes a third coil portion (3) which is part of a second electrical loop with a second quench protection element (8, 8?, 8?)as well as a heating element (9) which is supplied with a heating voltage in response to a quench of the third coil portion. Among the series connected coil portions (1, 2) only the second coil portion is in thermal contact with the first heating element (9).

Abstract: An apparatus (100) for quenching at least part (110) of a superconductor in a superconducting state in reply to a quench signal to initiate a transition from the superconducting state into a normal-conducting state comprises: means (120) for providing an alternating (AC) current of a predetermined strength and/or predetermined frequency to the at least part (110) of the superconductor, wherein the means (120) for providing the AC current comprises a control terminal (130) configured to receive the quench signal. The means (120) for providing the AC current is configured to be activated in response of receiving the quench signal at the control terminal (130) so that the AC current flows through the at least part (110) of the superconductor, wherein the predetermined strength and/or the predetermined frequency is selected such that the transition from the superconducting state into a normal-conducting state is triggered.

Abstract: The present invention is a superconducting partial insulation magnet and a method for providing the same. The magnet includes a coil with a non-insulated superconducting wire winding wound around a bobbin. The coil has a first wire layer, a second wire layer substantially surrounding the first layer, and a first layer of insulating material disposed between the first wire layer and the second wire layer. Each wire layer comprises a plurality of turns, and the first layer of insulating material substantially insulates the second wire layer from the first wire layer.

Abstract: A superconducting magnet includes a superconducting coil, a refrigerant container, a radiation shield, a vacuum container, a refrigerating machine cooling an interior of the refrigerant container, a tubular current lead passing from outside of the vacuum container to inside of the refrigerant container electrically connected to the superconducting coil, a power source electrically connected to the current lead, a manometer measuring a pressure inside of the refrigerant container, a thermometer to measure a temperature of the current lead, and a control unit connected to each of the power source, the manometer, and the thermometer. The control unit raises an output of the power source to vary a value of a current flowing into superconducting coil only when a measurement value of the manometer is higher than or equal to a set value and a measurement value of the thermometer is lower than or equal to a set value.

Abstract: A local coil for an imaging system includes a number of shim coils. A current for generating a shim field in one of the shim coils may be switched on and switched off. A current for generating a shim field in another of the shim coils may be switched on and switched off. The currents may be switched on and switched off independently of one another for generating a respective shim field in the shim coils.

Abstract: The present invention is a superconducting partial insulation magnet and a method for providing the same. The magnet includes a coil with a non-insulated superconducting wire winding wound around a bobbin. The coil has a first wire layer, a second wire layer substantially surrounding the first layer, and a first layer of insulating material disposed between the first wire layer and the second wire layer. Each wire layer comprises a plurality of turns, and the first layer of insulating material substantially insulates the second wire layer from the first wire layer.

Abstract: A terminal board is electrically connected to a module terminal of a semiconductor module. The semiconductor module and a cooling unit are laminated on the terminal board. A spring member is disposed on the semiconductor module and the cooling unit. A spring support tool is disposed on the spring member in order to apply, to the spring member, an urging force for pressing the semiconductor module and the cooling unit against the terminal board.

Abstract: Several embodiments of a novel technique for limiting transmission of fault current are disclosed. Current power distribution systems typically have an impedance, or reactor, on the output of the network equipment to limit current in the case of a fault condition. A low resistance switch, which changes its resistance in the presence of high current, is connected in parallel with this reactor. Thus, in normal operation, the current from the power generator bypasses the reactor, thereby minimizing power loss. However, in the presence of a fault, the resistance of the switch increases, forcing the current to pass through the reactor, thereby limiting the fault current.

Abstract: A rectifier comprising an electrically conductive support 32, a first plurality of rectifier components 24 carried by the support 32 and having their anodes connected to a first bus bar 26, a second plurality of rectifier components 28 carried by the support 32 and having their cathodes connected to a second bus bar 30, the cathode of each of the first rectifier components 24 being connected to the anode of an associated one of the second rectifier components 28, and first and second resistance paths 40, 42 between the first and second bus bars 26, 30 and the support 32.

Abstract: A portable magnet power supply for a superconducting magnet includes apparatus for the storage of energy released from a superconducting magnet, the apparatus having an electrical run-down load for connection across the electrical terminals of a superconducting magnet; and a heat storage material in thermal contact with the run-down load; and a method for use thereof.

Abstract: An electric power converter includes a cooler and an electronic circuit. The cooler includes a heat sink, a cooling fan, and a wind tunnel. A plurality of radiator fins are provided on a heat-sink base in the heat sink. The cooling fan is configured to feed cooling air through the plurality of radiator fins. The wind tunnel covers the plurality of radiator fins and the cooling fan. The electronic circuit includes a plurality of rectifiers and a plurality of input terminals. The plurality of rectifiers are provided on a side of the heat-sink base opposite to the plurality of radiator fins and are arranged side by side in a longitudinal direction of the heat-sink base. The plurality of input terminals are connected to the plurality of rectifiers with band-shaped conductors and are provided on a side of the plurality of rectifiers opposite to the heat sink.

Abstract: A superconducting magnet assembly is provided that includes a magnet protection system electrically coupled to a plurality of magnet coils to form a closed loop circuit. The magnet protection system includes a single superconducting switch to selectively connect a power supply to the plurality of magnet coils and also includes a plurality of dump resistors arranged to form a resistor ladder circuit, with each of the plurality of dump resistors being connected between magnet coils forming a respective symmetric coil pair. The magnet protection system also includes a heater network connected between ends of the closed loop circuit and to the plurality of magnet coils, with the heater network configured to perform a quench-back operation to protect the plurality of magnet coils during quench and being driven by a partial-magnet coil voltage generated in a magnet coil upon initiation of a quench condition in the magnet coil.

Abstract: A magnetic shielding arrangement, including: at least one magnetic flux source; a superconductor magnetic shield at least partially surrounding the magnetic flux source; a second shield at least partially surrounding the superconductor magnetic shield.

Abstract: 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.

Abstract: An energy dissipation arrangement for a cryogenically cooled superconductive magnet comprising a plurality of superconductive coils (10) connected in series and housed within a cryostat (24), comprising a superconducting switch (25) having a superconductive current path (28) in series with the superconductive coils (10); and a resistor (38), external to the cryostat, electrically connected in parallel with the superconductive current path (28) of the superconducting switch (25). The superconductive switch is arranged (26, 32, 30) to open in response to an electric current applied to an associated heater (26; 40).

Abstract: A method for progressively introducing current into, or removing current from, a superconducting coil mounted on a former, in which the coil vibrates relative to the former.

Abstract: The present invention relates to a system (100) for creating a magnetic field via a superconducting magnet (102) intended to produce said magnetic field. The system (100) according to the invention comprises a first branch including the superconducting magnet (102) formed by a coil inductance (L?) in series with a residual resistance (R?2), a second branch comprising a protection resistance (R?3) and a third branch comprising a power source (103). Furthermore, the system comprises a fourth branch formed by a resistance (R?1) mounted in series with a current-limiting superconducting device (106) switching from a low-resistance state to a high-resistance state when the current passing therethrough exceeds a breaking current, said first, second, third and fourth branches being mounted in parallel.

Abstract: An alternating current system 10 has a primary circuit 11 which forms a primary winding 18 on a core 16. A secondary winding 24 is connected with a current source 26 or, alternatively, with an impedance 60. The core 16 is threaded by a superconducting coil 20 having a current source 22. In normal use, current in the coil 20 provides a DC bias level of flux in the core 16, and the source 26 is varied to maintain substantially constant flux, thereby minimising losses in the primary circuit 11. In fault conditions, current in the coil 20 is reduced or removed to increase voltage losses across the coil 18, thereby limiting fault current. The impedance 60 can also be switched into circuit, creating further current limiting by virtue of the transformer effect of the windings 18, 24.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A system for ramping-down a superconducting magnet includes an electrically conductive lead connectable to a superconducting magnet and a plurality of diode assemblies arranged in series and coupled to the electrically conductive lead. Switches are arranged in parallel with the plurality of diode assemblies, with each switch having a first position and a second position and wherein each switch, when in the first position, forms an electrical short between first and second nodes of a corresponding diode assembly. A controller receives a magnet parameter value indicative of a present state of the superconducting magnet, determines a number of diode assemblies through which current from the electrically conductive lead is desired to pass based on the magnet parameter value, and selectively actuates the switches coupled to the determined number of diode assemblies to the second position to pass current from the superconducting magnet through the determined number of diode assemblies.

Abstract: A portable magnet power supply for a superconducting magnet includes apparatus for the storage of energy released from a superconducting magnet, the apparatus having an electrical run-down load for connection across the electrical terminals of a superconducting magnet; and a heat storage material in thermal contact with the run-down load; and a method for use thereof.

Abstract: A system for ramping-down a superconducting magnet includes an electrically conductive lead connectable to a superconducting magnet and a plurality of diode assemblies arranged in series and coupled to the electrically conductive lead. Switches are arranged in parallel with the plurality of diode assemblies, with each switch having a first position and a second position and wherein each switch, when in the first position, forms an electrical short between first and second nodes of a corresponding diode assembly. A controller receives a magnet parameter value indicative of a present state of the superconducting magnet, determines a number of diode assemblies through which current from the electrically conductive lead is desired to pass based on the magnet parameter value, and selectively actuates the switches coupled to the determined number of diode assemblies to the second position to pass current from the superconducting magnet through the determined number of diode assemblies.

Abstract: A loss can be reduced upon a current holding operation of a SMES. A superconducting magnetic energy storage (SMES) system includes a loop composed of a superconducting coil, a thyristor, and a synchronous rectification circuit, and a loop current flow through the loop. In a loop current hold mode, a switching control device of the synchronous rectification circuit turns on the thyristor, and the synchronous rectification circuit compensates for the loop current by rectifying an AC current from an AC power source to generate a DC current.

Abstract: A system for protecting superconducting generator field coils including a controller configured to monitor for a quenching of a superconducting field coil of a generator and control a dissipation of a current flow in the superconducting field coil in an event of the quenching, and an armature coil of the generator configured to cause the dissipation of the current flow in the superconducting field coil responsive to the controller in the event of the quenching of the superconducting field coil. A method for protecting superconducting generator field coils including monitoring for a quenching of a superconducting field coil of a generator, and dissipating a current flow in the superconducting field coil via an armature coil of the generator in response to a detection of the quenching.

Abstract: A coil system for inductively heating a superconducting magnet in order to provide an internal energy dump by uniformly quenching a high performance superconducting magnet. The quench-inducing system uses AC magnetic fields that require negligible reactive power. The system is especially suited for inducing a relatively uniform quench in dry superconducting magnets.

Abstract: An alternating current system 10 has a primary circuit 11 which forms a primary winding 18 on a core 16. A secondary winding 24 is connected with a current source 26 or, alternatively, with an impedance 60. The core 16 is threaded by a superconducting coil 20 having a current source 22. In normal use, current in the coil 20 provides a DC bias level of flux in the core 16, and the source 26 is varied to maintain substantially constant flux, thereby minimising losses in the primary circuit 11. In fault conditions, current in the coil 20 is reduced or removed to increase voltage losses across the coil 18, thereby limiting fault current. The impedance 60 can also be switched into circuit, creating further current limiting by virtue of the transformer effect of the windings 18, 24.

Abstract: An alternating current system 10 has a primary circuit 11 which forms a primary winding 18 on a core 16. A secondary winding 24 is connected with a current source 26 or, alternatively, with an impedance 60. The core 16 is threaded by a superconducting coil 20 having a current source 22. In normal use, current in the coil 20 provides a DC bias level of flux in the core 16, and the source 26 is varied to maintain substantially constant flux, thereby minimizing losses in the primary circuit 11. In fault conditions, current in the coil 20 is reduced or removed to increase voltage losses across the coil 18, thereby limiting fault current. The impedance 60 can also be switched into circuit, creating further current limiting by virtue of the transformer effect of the windings 18, 24.

Abstract: An electromagnet having at least one access port oriented perpendicularly to the electromagnet's central axis. The magnet has a conventional helical winding along its central axis. However, at some point along the length of the axis, the pitch of the helical winding is greatly increased in order to create a region with a comparatively low turn density. One or more ports are provided in this region. These ports provide access from the magnet's central bore to the magnet's exterior. A sample can be placed in the central bore near the ports. A beam traveling down the central bore, or through one of the radial ports, will strike the sample and be scattered in all directions. The ports allow access for instrumentation which is used to evaluate the scattered beam.

Abstract: A magnet coil system (2) which is at least partially superconducting at a cryogenic temperature, comprising at least two partial coils (3, 4, 5) which are connected in series and are each bridged by a superconducting switch (6, 7, 8), such that the partial coils form independent electric loops (11, 12, 13) when the superconducting switches (6, 7, 8) are closed, is characterized in that two electric loops (11, 12) have a common section and a flux pump (10) is provided which is circuited in the common section (14) of the electric loops (11, 12) of two partial coils (3, 4), wherein the sum of the currents of the two partial coils (3, 4) flows through the flux pump (10) in the operating state. In this fashion, the drifts of two independent electric loops can be compensated for with a few devices.

Abstract: There is disclosed a permanent current switch which has a high temperature margin and which is thermally stable and which securely performs a switching operation between a superconducting state and a normal conducting state. The permanent current switch of the present invention has a coiled superconducting wire and a heater wire which switches the superconducting wire between the superconducting state and the normal conducting state, the superconducting wire is a magnesium diboride superconducting wire having a high-resistance metal on an outer side and a magnesium diboride superconducting portion on an inner side and prepared by forming a superconducting metal on a layer between the high-resistance metal and the magnesium diboride superconducting portion, and the permanent current switch further comprises a superconductive connecting section superconductively connected to a lead wire guided from the superconducting wire and a superconducting wire for a wiring line.

Abstract: A magnet arrangement (M, M?, M?, M??) for generating a magnetic field in the direction of a z-axis in a working volume (V) disposed on the z-axis about z=0, with a magnet coil system (A, A?, A?, A??) which comprises one or more superconducting magnet partial coil systems (A1, A1?, A1?, A1??, A2??, . . ., An??), each forming superconductingly short-circuited current paths in the operating state, and with a further coil system (C, C?, C?, C??) which can be charged or discharged independently of the magnet coil system (A, A?, A?, A??) and comprises a first and a second partial coil system (C1, C2, C1? C2?, C1?, C2?, C1??, C2??), wherein the first partial coil system (C1, C1?, C1?, C1??) and the second partial coil system (C2, C2?, C2?, C2??) each comprise at least one coil, wherein all coils of the further coil system (C, C?, C?, C??) are connected in series, wherein gCeff,diamag>0.1 mT/A, is characterized in that gC1eff,diamag>0.1 mT/A, gC2eff,diamag>0.

Abstract: A localized area is at least partially contained within a perimeter of a shield ring formed by a closed superconducting current path of a material that is superconductive below a critical temperature. The shield ring is at least partially within a perimeter of a compensation coil that is coupled to a current source. One or more measurement devices are responsive to magnetic fields in the vicinity of the localized area, allowing compensation by controlling current to the compensation coil. A heater can raise temperature of the shield ring out of a superconducting condition.

Abstract: A superconducting magnet system comprising a superconducting magnet, itself comprising a plurality of magnet coils, arranged to protect quench heaters yet provide effective quench protection.

Abstract: Methods and apparatuses for improved damping in high-temperature superconducting levitation systems are disclosed. A superconducting element (e.g., a stator) generating a magnetic field and a magnet (e.g. a rotor) supported by the magnetic field are provided such that the superconducting element is supported relative to a ground state with damped motion substantially perpendicular to the support of the magnetic field on the magnet. Applying this, a cryostat housing the superconducting bearing may be coupled to the ground state with high damping but low radial stiffness, such that its resonant frequency is less than that of the superconducting bearing. The damping of the cryostat may be substantially transferred to the levitated magnetic rotor, thus, providing damping without affecting the rotational loss, as can be derived applying coupled harmonic oscillator theory in rotor dynamics. Thus, damping can be provided to a levitated object, without substantially affecting the rotational loss.

Abstract: A magnet configuration comprising a superconducting magnet coil system (M) and a current path (P) which comprises parts of the magnet coil system (M), wherein at least two electric connecting points (A1, A2, A3, A4) are disposed on the current path (P), which define a section (PA1-A2, PA2-A3, PA3-A4) within the current path (P), wherein the section (PA1-A2, PA2-A3, PA3-A4) does not comprise all parts of the magnet coil system (M) contained in the current path (P), and comprising a resistive element (WA1-A2, WA2-A3, WA3-A4) having an electric resistance value ?0, and at least two contacts (K1, K2, K3, K4), wherein the contacts (K1, K2, K3, K4) are disposed between the resistive element (WA1-A2, WA2-A3, WA3-A4) and one connecting point (A1, A2, A3, A4), is characterized in that in the superconducting state of the magnet coil system (M), an electric contact (K1, K2, K3, K4) between an electric connecting point (A1, A2, A3, A4) and a resistive element (WA1-A2, WA2-A3, WA3-A4) can be closed and opened.

Abstract: An inverter assembly including a storage compartment for multiple cables adapted to be releasably connected to the inverter. A body of the inverter assembly includes interior and exterior fins for the dissipation of heat energy.

Abstract: The present invention provides for a novel technique for placing superconducting magnets into operation. For example, the technique provides for automatically controlling ramp-up of a superconducting magnet. In one aspect, the technique includes connecting a power supply to the magnet, determining constraining parameters of the ramp-up, automatically applying power to the magnet, automatically controlling the ramp-up based on the constraining parameters, and wherein the ramp-up is complete upon reaching a predetermined value of a target parameter.