JP6463987B2 - Superconducting electromagnet device - Google Patents

Description

  The present invention relates to a superconducting electromagnet device composed of a superconducting coil.

  In a magnet device having a superconducting coil (superconducting magnet device), a heater (hereinafter referred to as a heater) capable of applying heat to the superconducting coil may be provided to intentionally induce quenching. . In this heater, for example, when a plurality of superconducting coils exist, when a quench occurs in a superconducting coil and this is detected, the current flowing through the superconducting coil is commutated to the heater and intentionally generated by the Joule heat generation. Is used to chain quench other coils.

Regarding such technology, for example, Patent Document 1 “provides a quench protection circuit that realizes quenching of a superconducting coil and quenching of a permanent current switch independently of each other together with highly reliable passive operation at the time of quenching of the superconducting coil”. "A resistance heater and a bidirectional diode connected in series are installed in the superconducting coil protection circuit, and a diode is installed in the permanent current switch protection circuit."

JP 2006-73571 A

  Conventional quench protection of a superconducting coil is performed by commutating a coil current to a heater as described above. However, the energization current, that is, the amount of heat generated by the heater, is limited so that the heater itself is not burned by the continuous heat generation caused by the continuous current flow.

Therefore, the problem to be solved by the present invention is to increase the value of the energizing current to the heater as much as possible at the initial stage when the normal conducting transition occurs in a part of the superconducting coil, and the electric current that attenuates the current transiently It is to provide a circuit configuration.

  In order to solve the above problems, there are various embodiments of the superconducting magnet device according to the present invention. As an example, a current power source, a plurality of superconducting coils connected to the current power source, and the current A diode connected in parallel to a power source; and a plurality of quench inducing means connected in series to the diode, the quench inducing means being in series with the heater resistance, the heater resistance, and the superconducting coil A magnetically coupled coil.

  In addition, when the breaker of the superconducting magnet device is cut off, the magnetic fluxes formed by the superconducting coil and the coil magnetically coupled to the superconducting coil are wound in opposite directions. This is a superconducting magnet device.

The method for protecting a superconducting magnet according to the present invention cuts off the circuit breaker via the quench detector when a part of the superconducting coil undergoes normal conduction transition, and the coil accompanying the interruption in the transient period in which the coil current attenuates. This is a method characterized by means for suppressing the current flowing through the heater by reducing the voltage across the heater using the induced electromotive force across the coil magnetically coupled to the superconducting coil, which is generated by the magnetic flux change corresponding to the current change.

  According to the present invention, when a part of the superconducting coil undergoes normal conduction transition, the circuit breaker is opened, the superconducting coil current is commutated to the heater, generating Joule heat, and other healthy coils are heated. Induced quenching protects the magnet without consuming all of the stored energy in a normal conducting transition. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

In addition, the current flowing into the heater for inducing the quenching of other healthy superconducting coils can be suppressed to a large value immediately after the circuit breaker opening operation and small during the transient period of coil current attenuation after the circuit breaker. If the total heat generation amount (time integration amount of heat consumed by the heater before the heater burns out) is a fixed value, the initial heat generation amount is higher than the heat generation amount in the heater shown in the known example Can be set. That is, since it is possible to shorten the time until quenching is induced for another healthy superconducting coil, a more reliable superconducting magnet protection operation is possible.

It is an electric circuit diagram of the superconducting magnet device according to the embodiment shown in the known example. It is an electric circuit diagram of the superconducting magnet device according to the embodiment shown in the known example. 1 is an electric circuit diagram of a superconducting electromagnet device according to a first embodiment of the present invention. It is a time transition diagram of the electric current using the electric circuit of the superconducting electromagnet apparatus which concerns on embodiment shown by the well-known example. It is a time transition diagram of the electric current using the electric circuit of the superconducting electromagnet apparatus which concerns on the 1st Embodiment of this invention. It is the electric circuit diagram used in order to confirm the effect of the 1st Embodiment of this invention. It is a time transition diagram of the electric current in the electric circuit used in order to confirm the effect of the 1st Embodiment of this invention. It is the electric circuit diagram used in order to confirm the effect of the 1st Embodiment of this invention. It is a time transition diagram of the electric current in the electric circuit used in order to confirm the effect of the 1st Embodiment of this invention. It is a concrete block diagram of the superconducting coil which concerns on the 1st Embodiment of this invention. It is a specific block diagram of the superconducting coil which concerns on the 3rd Embodiment of this invention.

It is the inductance matrix of the superconducting coil used for the calculation which concerns on the 1st Embodiment of this invention.

  The superconducting electromagnet apparatus includes a superconducting coil in a basic configuration. This superconducting coil is formed by winding a superconducting wire, but a part of it transitions from the superconducting state to the normal conducting state (normal conducting transition) and the phenomenon that the magnetic field disappears (quenching) occurs. There is a case. When this quench occurs, an electrical resistance is generated in the superconducting coil due to the normal conducting transition of the superconducting wire. A coil current flows through this electrical resistance and Joule heat is generated, the coil current is quickly attenuated, and the magnetic energy stored in the superconducting coil is quickly consumed. However, if magnetic energy is consumed locally at the quenched portion of the superconducting coil, the quenched coil may suffer fatal damage.

  Therefore, in order to ensure the soundness of the superconducting magnet device, the superconducting coil using metal such as NbTi or Nb3Sn is protected. For example, if a quench occurs, to avoid consuming the entire magnetic energy with a single quenched coil, the superconducting coil is split into multiple small closed circuits, and the magnetic energy is distributed and consumed in each closed circuit Let

  In addition, when a quench occurs, the superconducting coil is intentionally generated at a location where no quench occurs, preventing concentration of power inflow to a specific superconducting coil, and the accumulated magnetic energy can be reduced. A quench protection circuit is provided to quickly consume even other intentionally quenched superconducting coils (but no longer superconducting at this point).

  As a method used in this quench protection, (a) a superconducting coil and a heater (hereinafter referred to as a heater) that is in thermal contact with the superconducting coil in order to intentionally induce quenching are electrically connected, A method in which the current flowing through the superconducting coil is commutated to the heater when quenching of the superconducting coil is detected, and another coil group is intentionally chain-induced by the Joule heat generation, and (b) a separate heater is provided. There is a method of energizing the heater by installing a dedicated power supply and turning on the dedicated power supply when quenching is detected.

  In the method (a), since the coil current flows into the heater, it is necessary to appropriately design the energization amount to the heater so that the heater does not burn out. In the method (b), since the energization current to the heater can be adjusted by a dedicated power source, the possibility of burning is low, but the reliability of the dedicated power source is required. As the heater, for example, a sheet-like conductor made of stainless steel or copper can be used.

  In the protection circuit using the method (a), as a method for avoiding burning the heater, a method is shown in which a resistor is installed in parallel with the heater to shunt the coil current and suppress the current amount to the heater. And disclosed in Patent Document 1. A conceptual diagram of this circuit is shown in FIG.

  FIG. 1 is a circuit diagram of a superconducting magnet device according to the method (a), which is a known example. The current power source 11, the circuit breaker 12, and the protective resistor R0 of the current power source 11 connected in parallel thereto are connected in series with the superconducting coils L1, L2, and L3. Furthermore, it has a diode D1 connected in parallel to the current power source 11, and quench inducing means connected in series to the diode D1. The quench inducing means is composed of heaters R1, R2, and R3.

  In FIG. 1, for example, after a normal conduction transition occurs in a part of the superconducting coil L <b> 1, the circuit breaker 12 is opened in response to a signal from a quench detector that is not explicitly shown. As a result, the current flowing from the current power source 11 through the circuit breaker 12 to the superconducting coils L1, L2, and L3 flows from the superconducting coils L1, L2, and L3 through the diode D1 to the heaters R1, R2, and R3. The current is diverted to the flow path that flows to the protective resistance R0 provided in the path and the current power source.

  Subsequently, when the heaters R1, R2, and R3 are energized, the heaters generate Joule heat and the heat propagates, and the unquenched healthy superconducting coils L2 and L3 are heated to forcibly induce quenching. In addition, since the stored magnetic energy is distributed and consumed by the superconducting coils L1, L2, and L3, the soundness of the superconducting magnet can be ensured.

  However, when R0 >> R1, R2, and R3, the current flowing through the superconducting coils L1, L2, and L3 hardly flows to the protection resistor R0 side of the current power supply, and to the heaters R1, R2, and R3 sides. Flowing. For this reason, when the heat capacities of the heaters R1, R2, and R3 are not sufficient, there is a possibility that Joule heat generation due to the current becomes excessive and may cause fatal damage to the heater.

  Patent Document 1 also shows an example in which heater current adjustment resistors R10, R20, and R30 are provided in parallel with the heaters R1, R2, and R3, respectively. This method is referred to as a method (c).

  FIG. 2 is a circuit diagram of the superconducting magnet device according to the method (c). The current power source 11, the circuit breaker 12, and the protective resistor R0 of the current power source 11 connected in parallel thereto are connected in series with the superconducting coils L1, L2, and L3. Furthermore, it has a diode D1 connected in parallel to the current power source 11, and quench inducing means connected in series to the diode D1. The quench inducing means is composed of heaters R1, R2, R3 and heater energizing current adjusting resistors R10, R20, R30 connected in parallel to the heaters R1, R2, R3 in order to adjust the current value flowing through them. ing.

  In FIG. 2, for example, after a normal conduction transition occurs in a part of the superconducting coil L <b> 1, the circuit breaker 12 is opened in response to a signal from a quench detector that is not explicitly shown. As a result, the current flowing from the current source 11 through the circuit breaker 12 to the superconducting coils L1, L2, and L3 passes from the superconducting coils L1, L2, and L3 through the diode D1 to the heaters R1, R2, and R3 and the heaters described above. The commutation current commutates to the resistances R10, R20, R30 and the protective resistor R0 provided in the current power source 11.

  Subsequently, when the heaters R1, R2, and R3 are energized, the heaters generate Joule heat, and the healthy superconducting coils L2 and L3 that have not been quenched are heated to forcibly induce quenching. As a result, the coil resistance in the superconducting coils L1, L2, and L3 is increased, and the current flowing in the superconducting coils L1, L2, and L3 is attenuated, that is, the magnetism accumulated in the superconducting coils L1, L2, and L3. Quench protection is performed to dissipate energy in each coil and avoid damage to the coil L1 where the normal conduction transition first occurred.

  Here, the coil current flowing through the heaters R1, R2, and R3 is subtracted from the current that flows through the heater energizing current adjustment resistors R10, R20, and R30, so that the superconducting coils L1, L2, and L3 are quenched. The amount of heat input from the heater is smaller than that of a circuit composed only of the heaters R1, R2, and R3 of the method (a).

  The minimum amount of heat required for quench-inducing the superconducting coils L1, L2, and L3 raises the temperature of the superconducting coil to a temperature at which diversion starts to the stabilized copper inside the superconducting wire (diversion start temperature). It is given as the amount of heat necessary for this. When diversion starts to the stabilized copper, the normal conduction transition diffuses in an avalanche manner due to Joule heat generated by the stabilized copper, and the superconducting coil is quenched. However, since an insulating sheet such as kapton is provided between the superconducting coil and the heater to ensure electrical insulation, it becomes a thermal resistance and it is considered that a time delay occurs until the quenching of the superconducting coil occurs. .

  The temperature required to quench the superconducting coil by a normal conduction transition to the avalanche type depends on the current flowing through the superconducting coil and the strength of the magnetic field experienced, but considering the time delay, the amount of heat generated by the heater as much as possible And raising the temperature of the superconducting coil sharply to the above temperature is necessary to quickly quench another healthy superconducting coil.

  However, if the amount of heat generated by the heater is excessively increased, the heater temperature becomes excessively high and the possibility of burnout increases. Therefore, the resistance values of the energization amount adjustment resistors R10, R20, and R30 to the heater are determined by the upper limit of the transient temperature rise of the heater.

  The current decay time constant of the electric circuit composed of the superconducting coil, the heater resistance, and the protection resistance of the current power source is determined by the inductance value and the resistance value. If the current can be attenuated more quickly than this current decay (by designing the heater resistance value to be smaller), the initial heat generation at the heater can be further increased, in which case the temperature of the superconducting coil can be increased. Because it can be steeper, other healthy superconducting coils that are to be quenched can be transferred to normal conduction more quickly. Thereby, the temperature of the superconducting coil which started the normal conducting transition first can be suppressed to be lower, and the generated voltage between the superconducting coils can be further suppressed. Thereby, protection of a magnet apparatus can be implemented still more reliably.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted. In the following embodiments, three superconducting coils are used, but the present invention is not limited to this.

(First embodiment)
FIG. 3 is an electric circuit diagram showing the first embodiment of the superconducting magnet device 1 according to the present invention. The superconducting magnet device 1 shown in FIG. 3 includes superconducting coils L1, L2, and L3, coils L11, L21, and L31 magnetically coupled to the superconducting coil, heaters R11, R21, and R31 (heater resistance), and a diode D1. Are housed in a cryostat (not shown), and are connected to a current power source 11 including a protective resistor R0 of the current power source 11 and a circuit breaker 12.

  The superconducting coils L1, L2, and L3 of this embodiment and the coils L11, L21, and L31 magnetically coupled to the superconducting coil are coils having a winding number of about 10: 1 and an inductance ratio of about 100: 1. is there. As shown in the calculation results in Examples described later, the induced electromotive force generated at both ends of the coils L11, L21, and L31 due to the current change of the superconducting coils L1, L2, and L3 is more than the induced electromotive force due to the self-inductance. This is a coil geometry in which the induced electromotive force due to inductance appears more prominently. Therefore, if the electromotive force induced in the superconducting coil L1 is Vab and the electromotive force induced in the coil L11 magnetically coupled to the superconducting coil L1 is Vcd, Vab and Vcd have induced electromotive forces having the same sign. Occur.

  In the electric circuit shown in FIG. 3, during excitation using the current power supply 11, a current path is formed that flows from the current power supply 11 to the superconducting coils L <b> 1, L <b> 2, L <b> 3 through the circuit breaker 12. Since the backflow prevention diode D1 is installed in the line including the heater, no current flows unless the turn-on voltage (for example, 5 V) of the diode D1 is exceeded. Therefore, at the time of excitation, the excitation speed is set so that the electromotive force induced in the superconducting coils L1, L2, and L3 accompanying the current change does not exceed the turn-on voltage.

  For example, after a normal conducting transition occurs in a part of the superconducting coil L1, the circuit breaker 12 is opened in response to a signal from a quench detector which is not clearly shown. As a result, the current flowing from the current power source 11 through the circuit breaker 12 to the superconducting coils L1, L2, and L3 is transferred from the superconducting coils L1, L2, and L3 through the diode D1 to the heaters R1, R2, and R3 and the superconducting coils. Are commutated and shunted to coils L11, L21, L31 magnetically coupled to the protection resistor R0 provided in the current power source 11. In the initial process immediately after the circuit breaker 12 is opened, since the normal conducting transition portion generated in the superconducting coil L1 is still small, the resistance value is small and the amount of current attenuation is small. The induced electromotive force induced by L11 is also small. Since the protection resistance R0 of the current power supply 11 is sufficiently larger than the heater resistances R11, R21, and R31, the current flowing through the heater is substantially equal to the coil current.

In the transition period in which the breaker 12 is opened and the superconducting coil current is attenuated, the voltages at both ends of the superconducting coils L1, L2, and L3 are VL1, VL2, VL3, and coils L11, L21 magnetically coupled to the superconducting coil, respectively. , L31 and heaters R11, R21, R31, respectively, the voltages at both ends are VL11, VL21, VL31, VR11, VR21, VR31,
VL1 + VL2 + VL3 = VL11 + VL21 + VL31 + VR11 + VR21 + VR31> VR11 + VR21 + VR31 (1)
The voltage across the heater is smaller than when there is no coil L11, L21, L31 magnetically coupled to the superconducting coil (in the case of method (a)). That is, in the transition period in which the circuit breaker 12 is opened and the superconducting coil current is attenuated, the current flowing through the heater is small, so the heater heat generation is small.

  That is, in the initial stage when the breaker 12 is opened and the superconducting coil current is attenuated, almost all of the current flowing through the superconducting coils L1, L2, and L3 flows into the heaters R11, R22, and R33 via the diode D1. However, in the transition period, the current flowing through the heater is suppressed.

  Next, specific numerical calculation results are shown. The protective resistance R0 installed in the current power source 11 is 1Ω, the inductances of the superconducting coils L1, L2, and L3 are 1.8H, and the inductances of the coils L11, L12, and L13 magnetically coupled to the superconducting coils are 0.02H (turn The number is about 1/10 of the number of superconducting coil turns, and the resistance value of the heater is a value depending on the temperature of the material SUS304. The superconducting coils L1, L2, and L3 are arranged on the same axis, and Table 1 is used for the self-inductance and mutual inductance of the superconducting coil and the coils L11, L12, and L13 magnetically coupled to the superconducting coil. The rated current value of the superconducting coil was 410A.

  When a part of the superconducting coil undergoes normal conduction transition, the temperature rises due to Joule heat generation in that part, and a resistance depending on the temperature is generated. Moreover, current attenuation occurs due to this resistance, and an AC loss is generated in the superconducting wire due to a magnetic field change caused by this, and the resistance value increases. For the stabilized copper of the superconducting wire, a specific resistance value depending on the temperature of copper having a residual resistance ratio (RRR) of 60 was used.

  FIG. 4 shows a current transition after the circuit breaker 12 opening operation when only a resistor as a heater shown in FIG. 1, which is a known example, is connected as a reference. This electric circuit has a current decay waveform according to the exponential function of the LR circuit due to the superconducting coil and resistance.

  On the other hand, FIG. 5 shows a current transition after the circuit breaker 12 is opened when the electric circuit according to this embodiment of FIG. 3 is used. Near the time t = 0 immediately after the circuit breaker 12 is opened, substantially the same current flows in the heater as in FIG. Thereafter, due to the electromotive force induced at both ends of the coil magnetically coupled to the superconducting coil, the voltage across the heater is lowered, and the current flowing through the heater is sharply reduced. That is, in the superconducting magnet having the circuit described in the present embodiment, the current flowing in the superconducting coil flows almost as it is into the heaters R11, R21, and R31 for inducing quenching immediately after the occurrence of quenching. Not enough superconducting coils generate enough heat to induce quench. On the other hand, when an induced electromotive force is generated in the coils L11, L21, and L31 magnetically coupled with the current attenuation of the superconducting coil, the current is immediately diverted to the protective resistance side. In particular, if the induced electromotive force in L11, L21, and L31 is increased, the amount of current flowing into the protective resistor R0 is greater than the amount of current flowing into the heaters R11, R21, and R31. This result is clearly different from the result obtained by connecting only the resistance as the heater shown in the known example.

  Next, it is clear from FIGS. 6 and 7 that the contribution of mutual inductance between the superconducting coil and the coil magnetically coupled to the superconducting coil is large. FIG. 6 shows an example in which the coils L11, L211, and L31 are installed far from the superconducting coils L1, L2, and L3 as compared to the case shown in FIG. The calculation result in this case is shown in FIG. In this case, since the magnetic coupling between the coils L11, L21, L31 and the superconducting coil can be ignored, only the self-inductance of the coils L11, L21, L31 is taken into account. Under such conditions, the current transition after the opening operation of the circuit breaker 12 is shown in FIG. Each current decay waveform is very similar to the waveform when only the resistor as the heater is connected. This result shows that the influence of the self-inductance has a small contribution in this electric circuit, and the contribution of the mutual inductance is large.

  Further, in order to confirm the contribution of mutual inductance, an electric circuit in which the winding directions of the coils L11, L21, and L31 were reversed as shown in FIG. 8 was used. The current transition after the breaker 12 opening operation is shown in FIG. Since the voltages generated at both ends of the coils L11, L21, and L31 are in opposite directions, the voltage at both ends of the heater is increased in reverse, and the current flowing through the heater is increased. This result also confirms that this tendency is determined by the contribution of mutual inductance.

  As described above, the superconducting magnet device of the present embodiment includes a superconducting coil, a coil magnetically coupled to the superconducting coil, and a resistor (heater) connected in series with the coil. A generating means is provided. By having this configuration, immediately after quenching, since the current change generated in the superconducting coil is minute, the voltage induced by the mutual inductance between the coils L11, L21, L31 and the superconducting coil is small, and the coil L11, It can be approximated that L21 and L31 are short-circuited. On the other hand, since the sum of the resistance values of the heaters R11, R21, R31 is small compared to the protective resistance R0, when the circuit breaker 12 is opened, when the diode D1 is turned on, the current flowing through the superconducting coil is It flows into the heaters R11, R21, R31. In other words, as shown in FIG. 5, at the moment when quenching occurs in the superconducting coil, the heat generation (current) of the heaters R11, R21, and R31 advances rapidly, and heat is applied to the superconducting coil. .

  In the heaters R11, R21, and R31, unlike the conventional case, the current flowing in the superconducting coil flows without being shunted, so the amount of heat generated is larger than in the conventional case. Therefore, in the superconducting coil to which this heat is applied, an avalanche-type normal conduction transition occurs faster than before. Since the normal conduction transition occurs at an accelerated rate, the current change in the superconducting coil transitions from a very small one to a large one, so the coils L11, L21, and L31 that are magnetically coupled to this superconducting coil are mutually connected. An induced electromotive force is generated by the inductance. As a result, the current flowing through the heater portion rapidly decreases, the current flowing through the protective resistor R0 increases rapidly, and the magnetic energy can be released by the protective resistor R0.

  That is, according to the superconducting magnet device of the present embodiment, when a part of the superconducting coil has a normal conducting transition, the circuit breaker is opened, and the superconducting coil current is commutated to the heater to generate Joule heat, Other healthy coils are thermally quenched to protect the magnet without consuming all of the stored energy in a normally conducting transition coil.

In addition, the current flowing into the heater for inducing the quenching of other healthy superconducting coils can be suppressed to a large value immediately after the circuit breaker opening operation and small during the transient period of coil current attenuation after the circuit breaker. The total heat generation amount (time integrated amount of heat consumed by the heater before the heater burns out) can be set to a value higher than the heat generation amount of the heater shown in the known example. That is, since it is possible to shorten the time until quenching is induced for another healthy superconducting coil, a more reliable superconducting magnet protection operation is possible.

FIG. 10 shows a specific configuration of the superconducting coil according to the first embodiment of the present invention. The superconducting coil 22 is wound along a bobbin 21 coaxial with the central axis of symmetry, and the winding end is fixed using a hole on the side surface of the bobbin (not shown). The outer side surface of the wound superconducting coil 22 is fixed with a resin 23 or the like, and a coil 24 magnetically coupled to the superconducting coil 22 is wound thereon. These coils 22 and 24 are substantially coaxial coils. A glass braid insulation 25 or the like for preventing the coil 24 from collapsing is wound around the outer side surface. Further, a part of the bobbin is hollowed out and a heater 26 is installed via an insulating sheet 27 so that the heater 26 can be installed inside the superconducting coil.
(Second Embodiment)
The winding method of the coil which magnetically couples with the said superconducting coil in connection with the 2nd Embodiment of this invention is shown. The superconducting magnet device 1 may include an iron core (not shown) for forming a magnetic path for the purpose of suppressing a leakage magnetic field. Although the coupling coefficient is smaller than when the coil magnetically coupled to the superconducting coil is coaxially wound with the superconducting coil, the same effect as in the first embodiment of the present invention can be obtained.
(Third embodiment)
FIG. 11 shows a winding method of the copper wire 32 for forming a coil magnetically coupled to the superconducting wire 31 according to the third embodiment of the present invention. A conductor used for the coil, for example, a copper wire 32 is wound together with the superconducting wire 31 to form superconducting coils L1, L2, and L3. Since the copper wire 32 has a resistance value, Joule heat is generated when the breaker 12 opens and the superconducting coil current flows. Since the copper wire 32, which is a heating element, is present in the superconducting coil, the entire superconducting coil is transferred to the normal conducting state faster than the case where other healthy superconducting coils are transferred to the normal conducting state due to heat transfer from the heater. be able to.

1 Superconducting magnet device 1
11 Current supply 11
L1, L2, L3 Superconducting coils L11, L21, L31 Coils magnetically coupled to the superconducting coils R0 Protection resistance D1 Diodes R11, R21, R31 Heater resistance R10, R20, R30 Heater current adjustment resistance 12 Breaker 12
21 Bobbin 22 Superconducting coil 23 Resin 24 Coil magnetically coupled to the superconducting coil 25 Glass braided insulating sheet 26 Heater 27 Insulating sheet 31 Superconducting wire 32 Copper wire

Claims (5)

A current source; and a protective resistor connected in parallel to the current source;
A plurality of superconducting coils connected in parallel to the current source;
A diode connected in parallel to the current source;
A plurality of quench inducing means connected in series to the diode;
A circuit breaker connected in series to the current power source ,
The quench inducing means is
Heater resistance,
A coil in series with the heater resistor and magnetically coupled to the superconducting coil ,
When the circuit breaker is opened, and a current flows through an electric circuit closed by the superconducting coil, the quench inducing means, and the diode, the superconducting coil and a coil magnetically coupled to the superconducting coil; superconducting magnet apparatus the direction of the magnetic flux is that is winding to be opposite each make it.   The superconducting magnet apparatus according to claim 1, wherein the quench inducing means is installed for a plurality of superconducting coils.   The superconducting device according to claim 1, wherein the quench inducing means are connected in series to form a quench inducing means group, and the quench inducing means group is connected in parallel to the current power source. Magnet device.   The superconducting magnet device according to claim 1, wherein a coil magnetically coupled to the superconducting coil is wound substantially coaxially with the superconducting coil. Superconducting magnet apparatus according to claim 1 is provided with an iron core for forming a magnetic path,
The superconducting magnet device according to claim 1 , wherein a coil magnetically coupled to the superconducting coil is wound around the iron core.