JP2006332559A - Persistent current superconducting magnet and persistent current switch used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a persistent current superconducting magnet and a persistent current switch used for this magnet by which quench of a high-temperature superconducting coil can be reliably prevented, the permanent current can be attenuated without quenching the high-temperature superconducting coil, and the high-temperature superconducting coil can be protected accordingly. <P>SOLUTION: The persistent current superconducting magnet 10 has the high-temperature superconducting coil 13 which is housed in a vacuum container 11, the persistent current switch 14 which is thermally connected with the high-temperature superconducting coil 13, a heat insulation means 12 which insulates the high-temperature superconducting coil 13 and the persistent current switch 14 from the external environment, a cooling means 18 which cools the high-temperature superconducting coil 13 and the persistent current switch 14, and a current carrying means 23 for exciting the high-temperature superconducting coil 13 through a current lead 22. The quenching temperature of the persistent current switch 14 is set lower than the quenching temperature of the high-temperature superconducting coil 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a permanent current superconducting magnet used in a superconducting device and a permanent current switch used in the magnet.

  Conventionally, this type of permanent current superconducting magnet and the permanent current switch used for this magnet are disclosed in Japanese Patent Laid-Open No. 2003-69093 (Patent Document 1) and Japanese Patent Laid-Open No. 2003-142744 (Patent Document 2). There is something.

  A permanent current superconducting magnet used in a conventional superconducting device is a high temperature superconducting wire that houses a high temperature superconducting coil and a permanent current switch in a vacuum vessel via a radiation shield, and short-circuits the high temperature superconducting coil and the permanent current switch. Connected to form a permanent current circuit.

  The high temperature superconducting coil and the permanent current switch are cooled directly via the coil heat transfer plate and the switch heat transfer plate by a refrigerator provided in the vacuum vessel, while the high temperature superconducting coil is excited via the current lead by the excitation power source. It has come to be.

In a conventional permanent current superconducting magnet, when a high-temperature superconducting coil is excited by an excitation power source, the permanent current flows through a permanent current circuit consisting of a high-temperature superconducting coil and a permanent current switch. Function can be continuously demonstrated and maintained.
JP 2003-69093 A JP 2003-142744 A

  In the conventional permanent current superconducting magnet, when the permanent current is maintained, the cooling means of the high temperature superconducting coil has failed due to failure of the refrigerator, functional deterioration, power failure, etc., or for some reason from the outside of the vacuum vessel When the invading heat increases, the coil temperature of the high-temperature superconducting coil rises and may eventually be quenched.

  The high-temperature superconducting coil is a very expensive coil constructed by winding a large number of high-temperature (oxide) superconducting wires in a torus shape or a donut shape. When the high-temperature superconducting coil is quenched, a resistance portion is generated in the high-temperature superconducting wire of the coil, and the accumulated energy of the coil of the high-temperature superconducting coil is converted into thermal energy by this resistance portion, so that the permanent current is attenuated.

  Heat generated in the resistance part of the high-temperature superconducting coil may cause thermal distortion and reduce the performance of the high-temperature superconducting wire. In the worst case, the quenching of the high-temperature superconducting coil causes the high-temperature superconducting wire to burn out. There is also.

  The high temperature superconducting coil has an operating temperature as high as 20K to 40K as compared with the low temperature superconducting coil, so that the specific heat is large and the quench temperature is difficult to propagate. Since the quench temperature is difficult to propagate at the time of quenching the high-temperature superconducting coil, the generated resistance portion does not expand and generates heat locally. For this reason, as a result, the stored energy of the high-temperature superconducting coil is handled by a heat capacity in a small region, and there is a problem that performance degradation and burnout easily occur due to thermal distortion.

  In addition, in the conventional permanent current superconducting magnet, the internal structure of the permanent current switch is described in detail, but there is a possibility that quenching may occur in the high temperature superconducting coil, and no consideration is given to countermeasures when quenching occurs not exist.

  The present invention has been made in consideration of the above-described circumstances. Even if the temperature of the high-temperature superconducting coil rises, the high-temperature superconducting coil can be prevented from quenching without fail, and the permanent current can be obtained without quenching the high-temperature superconducting coil. An object of the present invention is to provide a permanent current superconducting magnet capable of attenuating the high temperature superconducting coil and protecting the high temperature superconducting coil, and a permanent current switch used for the magnet.

  Another object of the present invention is to adjust the quenching temperature of the permanent current switch to be lower than the quenching temperature of the high-temperature superconducting coil to prevent the quenching of the high-temperature superconducting coil in advance and to ensure that the high-temperature superconducting coil is not damaged or burned out. It is an object of the present invention to provide a permanent current superconducting magnet and a permanent current switch used for the magnet.

  In order to solve the above-described problem, a permanent current superconducting magnet according to the present invention is thermally connected to a high-temperature superconducting coil housed in a vacuum vessel and the high-temperature superconducting coil. A permanent current switch; heat insulating means for insulating the high temperature superconducting coil and the permanent current switch from an external environment; cooling means for cooling the high temperature superconducting coil and the permanent current switch; and exciting the high temperature superconducting coil via a current lead. And a quench temperature of the permanent current switch is set lower than a quench temperature of the high temperature superconducting coil.

  Further, in order to solve the above-mentioned problem, the permanent current superconducting switch according to the present invention is a superconducting conductor as described in claim 8 in which a band-like high-temperature superconducting thin film is formed on a metal plate or an insulating substrate. In this superconducting conductor, the conductor width of the high-temperature superconducting thin film can be adjusted and set, and the quench temperature can be adjusted.

  The permanent current superconducting magnet according to the present invention can attenuate the permanent current without quenching the high temperature superconducting coil by adjusting the quench temperature of the permanent current switch to be lower than the quench temperature of the high temperature superconducting magnet. The coil can be protected.

  Embodiments of a permanent current superconducting magnet according to the present invention and a permanent current switch used in the magnet will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic overall configuration diagram showing a first embodiment of a permanent current superconducting magnet of the present invention used in a superconducting device such as a linear motor.

  In the permanent current superconducting magnet 10, a radiation shield 12 of Al, Cu or C-FRP (carbon fiber reinforced plastic) is housed in a box-shaped vacuum vessel 11 as a heat insulation means for heat insulation from the external environment. A torus-shaped or donut-shaped high-temperature superconducting coil 13 and a permanent current switch 14 are accommodated and insulated from the external environment. The high-temperature superconducting coil 13 is made of an oxide superconductor, and is accommodated in the vacuum vessel 11 by one or plural, for example, four. The high-temperature superconducting coil 13 is connected to a permanent current switch 14 and a high-temperature superconducting wire 15, and a permanent current circuit 16 is configured in the vacuum vessel 11.

  In addition, a refrigerator 18 is provided as a cooling means for the high-temperature superconducting coil 13 in the vacuum vessel 11 containing the high-temperature superconducting coil 13, and a coil heat transfer means 19 comprising a flexible heat transfer plate or the like by operation of the refrigerator 18. The high temperature superconducting coil 13 is cooled to about 10K to 77K, preferably 20K to 40K. The high temperature superconducting coil 13 is thermally connected to the permanent current switch 14 via the switch heat transfer means 20, and the high temperature superconducting coil 13 and the permanent current switch 14 are cooled to substantially the same cooling temperature.

  Thus, the high temperature superconducting coil 13 and the permanent current switch 14 are cooled by the refrigerator 18 through the heat transfer means 19 and 20. The switch heat transfer means 20 keeps the permanent current switch 14 at substantially the same temperature as the high temperature superconducting coil 13 except when the permanent current switch 14 generates a large amount of heat, such as when the permanent current switch 14 is heated to turn off. Designed to be

  Further, the permanent current circuit 16 is provided with a current lead 22 for exciting the high-temperature superconducting coil 13 in parallel with the permanent current switch 14, and the coil exciting current lead 22 is provided with an exciting power source 23 as an energizing means. The excitation power source 23 is installed outside the vacuum vessel 11, for example, at a room temperature. The excitation power source 23 is electrically connected to the high temperature superconducting coil 13 via the current lead 22 and functions as an excitation for the high temperature superconducting coil 13. The excitation power source 23 excites the high-temperature superconducting coil 13 by turning off the permanent current switch 14.

  Further, a permanent current switch superconducting conductor 25 as shown in FIG. 2 is used for the permanent current switch 14. The superconducting conductor 25 is formed by forming a high-temperature superconducting thin film 27 having a thickness of several μm or less, for example, 1 μm, on a metal or sapphire insulating substrate 26 in a strip shape, and via electrodes 28 and 29 provided at both ends. It is electrically connected to the high temperature superconducting wire 15. The superconducting conductor 25 for the permanent current switch is connected to the high-temperature superconducting coil 13 via the high-temperature superconducting wire 15 by the electrodes 28 and 29 at both ends.

  The width W of the conductor constituting the high-temperature superconducting thin film 27 can be easily adjusted by cutting the patterning. By adjusting the conductor width W, the temperature at which the permanent current switch 14 quenches can be freely designed. it can. The quench temperature of the permanent current switch 14 is designed to be lowered by reducing the conductor width W, and to reliably quench at a temperature lower than the quench temperature of the high-temperature superconducting coil 13.

  In this permanent current superconducting magnet 10, a superconducting conductor 25 in which a high temperature superconducting thin film 27 is formed in a strip shape on a metal or insulator substrate 26 is used for the permanent current switch 14, and the conductor width W of the high temperature superconducting thin film 27 is set. By changing the setting, the adjustment setting of the quench temperature of the permanent current switch 14 can be facilitated.

  In addition, when the permanent current switch 14 is quenched, a metal protective layer 30 may be provided on the high temperature superconducting thin film 27 as shown in FIG. FIG. 3 shows a cross-sectional view of a permanent current switch superconducting conductor 25A provided with a metal protective layer 30. A good conductor such as Au or Ag is used for the metal protective layer 30. The permanent current switch superconducting conductor 25A is a modification of the permanent current switch 14.

  Since a superconducting conductor in which a belt-like high-temperature superconducting thin film 27 is formed on a metal or insulator substrate 26 is used as the superconducting conductor 25 (25A) used for the permanent current switch 14, the quenching temperature can be easily set, and the quenching temperature is increased. The permanent current switch 14 set lower than the superconducting coil 13 can be provided.

  This permanent current superconducting magnet 10 uses a permanent current switch 14 in which a metal protective layer 28 is formed on a belt-like high-temperature superconducting thin film 27. When the permanent current switch 14 is quenched, the current flowing in the high-temperature superconducting thin film 27 is shunted to the metal protective layer 30, so that the permanent current switch 14 is difficult to burn out.

  Next, the operation of the permanent current superconducting magnet 10 will be described.

  In the permanent current superconducting magnet 10, the excitation power source 23 is connected to the high temperature superconducting coil 13 through the current lead 22 by turning off the permanent current switch 14, and the high temperature superconducting coil 13 is excited. At this time, the high temperature superconducting coil 13 and the permanent current switch 14 are cooled to, for example, about 10K to 77K, preferably about 20K to 40K through the heat transfer means 19 by the operation of the refrigerator 18.

  Thereafter, by turning on the permanent current switch 14, the permanent current circuit 16 enters a permanent current mode operation. By this permanent current mode operation, the high temperature superconducting coil 13 continues to be excited, and the magnet function is maintained as a superconducting magnet.

  When the cooling of the high-temperature superconducting coil 13 becomes defective due to some cause such as failure of the refrigerator 18 during the permanent current mode operation, the temperature of the high-temperature superconducting coil 13 may rise and quench, which is very expensive. There is a possibility that the high-temperature superconducting coil 13 cannot be sufficiently protected.

  When the high-temperature superconducting coil 13 is used for the permanent current superconducting magnet 10, the quench propagation is very slow. Therefore, the energy stored in the high-temperature superconducting coil 13 is consumed at a local site in the vicinity of the quenching place, and eventually the coil burns out. May occur.

  In the permanent power superconducting magnet 10 of the first embodiment, the quenching temperature of the permanent current switch 14 is adjusted by cutting the conductor width W of the superconducting thin film 27 for the permanent current switch used for the permanent current switch 14 by adjusting the width. Can be set. The permanent current switch 14 is set to a quench temperature so as to be surely quenched at a temperature several degrees to several ten degrees lower than the temperature at which the high-temperature superconducting coil 13 quenches, for example, a temperature 10 K lower. For example, when the quench temperature of the high-temperature superconducting coil 13 is 40K (60K), the permanent current switch 14 is designed to quench at 30K (50K).

  The permanent current superconducting magnet 10 is designed such that the temperature T2 at which the permanent current switch 14 quenches is lower (T1> T2) than the temperature T1 at which the high temperature superconducting coil 13 quenches. However, the quench temperatures T <b> 1 and T <b> 2 are actually temperatures for quenching in the operating state of the permanent current superconducting magnet 10. Depending on the cooling state of the high-temperature superconducting coil 13 and the permanent current switch 14, the quench temperatures T1 and T2 are not necessarily temperatures at which the permanent current value becomes a critical current value defined by 1 μV / cm.

  In the permanent current superconducting magnet 10 of the present embodiment, since the permanent current switch 14 quenches at a temperature lower than that of the high temperature superconducting coil 13, the accumulated energy of the high temperature superconducting coil 13 passes through the permanent current switch heat transfer means 20. Since the entire high-temperature superconducting coil 13 is heated, the permanent current magnet 10 capable of attenuating the permanent current without quenching the high-temperature superconducting coil 13 can be provided.

  According to the permanent current superconducting magnet 10, the permanent current switch 14 is designed to quench at a temperature lower than that of the high temperature superconducting coil 13. Therefore, even when the temperature of the high temperature superconducting coil 13 rises, the high temperature superconducting magnet 10. The permanent current superconducting magnet 10 in which the coil 13 is not quenched can be provided.

  Further, the permanent current superconducting magnet 10 is permanent even if the temperature of the high-temperature superconducting coil 13 rises due to heat entering from the outside of the vacuum vessel 11 or a malfunction of the refrigerator 18 as a cooling means. Since the current switch 14 is quenched first, the permanent current can be attenuated without quenching the high temperature superconducting coil 13.

  FIG. 4 is a schematic overall configuration diagram showing a second embodiment of the permanent current superconducting magnet according to the present invention.

  In the description of this embodiment, the same components as those of the permanent current superconducting magnet 10 shown in FIG. The permanent current superconducting magnet 10A shown in FIG. 4 is provided with a protective resistor 33 at the room temperature outside the vacuum vessel 11 in the permanent current superconducting magnet 10 shown in FIG. 1, and this protective resistor 33 is connected to the current lead 22. The coil protection circuit 31 of the high temperature superconducting coil 13 is configured. This permanent current superconducting magnet 10A also has the same operation and effect as the superconducting magnet 10 shown in the first embodiment.

  When the protective resistor 33 installed in the room temperature portion is connected in parallel with the permanent current switch 14, when the permanent current switch 14 is quenched during the permanent current mode operation, the current flowing through the permanent current switch 14 is supplied to the protective resistor 33. The protective resistor 33 can consume most of the energy stored in the high-temperature superconducting coil 13. For this reason, the thermal load with respect to the permanent current switch 14 can be reduced. The protective resistor 33 may be installed outside or inside the vacuum vessel 11 as long as it is at room temperature.

  In addition, even if the permanent current switch 14 is burned out and disconnected, there is an advantage that the permanent current circuit 16 is not opened. However, if the protection resistor 33 is connected in parallel with the permanent current switch 14, the current flowing from the excitation power source 23 during excitation or demagnetization is shunted to the coil protection circuit side of the protection resistor 33 according to the excitation voltage, that is, the excitation speed. The protective resistor 33 generates heat. The reason for installing the protective resistor 33 on the room temperature side is to prevent the adverse effect of the heat generated by the protective resistor 33 from reaching the high temperature superconducting coil 13.

  In the permanent current superconducting magnet 10 </ b> A, a protective resistor 33 is connected in parallel to the permanent current switch 14. When the current switch 14 is permanently quenched, the current is shunted to the protective resistor 33, so that heat generation in the permanent current switch 14 can be reduced.

  FIG. 5 is a schematic overall configuration diagram showing a third embodiment of the permanent current superconducting magnet according to the present invention.

  The permanent current superconducting magnet 10B shown in this embodiment has a protection circuit 35 connected to the permanent current circuit 15 (in parallel), and the other configuration and operation are the permanent current superconducting shown in the first embodiment. Since it is not different from the magnet 10, the same components are denoted by the same reference numerals and description thereof is omitted.

  The permanent current superconducting magnet 10B shown in FIG. 5 includes a coil protection circuit 35 including a protection resistor 33 and a protection lead 34, and the protection lead 34 of the protection circuit 35 is connected to the high temperature superconducting wire 15 of the high temperature superconducting coil 13. It is a thing.

  In the permanent current superconducting magnet 10B, the current lead 22 may be removed in order to reduce the thermal load on the radiation shield 12 or the high temperature superconducting coil 13 after achieving the permanent current mode operation. In this case, since the protective resistor 33 cannot be connected, a coil protective circuit 35 that can be connected to the permanent power circuit 16 is provided, and a protective lead 34 for connecting the high-temperature superconducting coil 13 and the protective resistor 33 as shown in FIG. Is installed. Even if the permanent current switch 14 is quenched, the protective lead 34 can commutate the permanent current to the protective resistor 33. However, the current does not flow much except when the stored energy of the coil is consumed as heat. It is possible to design the infiltration heat to be smaller than that of the normal current lead 22.

  In the permanent current superconducting magnet 10B shown in the third embodiment, the same effect as that of the superconducting magnet 10 shown in the first embodiment is obtained, and after the permanent current mode operation is achieved, the current lead 22 is removed and radiation is performed. The heat load on the shield 12 and the high-temperature superconducting coil 13 can be reduced.

  In this permanent current superconducting magnet 10B, in addition to the current lead 22 for exciting the high temperature superconducting coil 13, a coil protection circuit 35 provided with a protective lead 34 for connecting the high temperature superconducting coil 13 and the protective resistor 33 is provided. Yes. Even if the exciting current lead 22 is removed in order to reduce the intrusion heat, the protective resistor 33 can always be connected via the protective lead 34, and the same effect as the second embodiment can be obtained.

  FIG. 6 is an overall configuration diagram schematically showing a fourth embodiment of the permanent current superconducting magnet according to the present invention.

  This permanent current superconducting magnet 10C is provided with a coil protection circuit 37 in which a protection resistor 33 and an ON-OFF switch 36 are connected in series with each other (connected in parallel) to the permanent current circuit 15. Other configurations and functions are as follows. Since it is not different from the permanent current superconducting magnet 10 shown in the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  The permanent current superconducting magnet 10C shown in FIG. 6 includes a protective resistor 33 and an ON-OFF switch 36 connected in series to a coil protection circuit 37 provided in parallel with the permanent current circuit 15, and the protective resistor 33 and the ON- A protection lead 34 provided with an OFF switch 36 is connected to the high temperature superconducting wire 15 of the high temperature superconducting coil 13.

  In the permanent current superconducting magnet 10C, the permanent current can be shunted from the permanent current circuit 15 to the coil protection circuit 37 side. In order to prevent the high-temperature superconducting coil 13 from generating heat, an ON-OFF switch 36 is provided to turn on and off using the coil protection circuit 37 as a switch means, and the protection circuit 37 is disconnected from the permanent current circuit 16 during excitation and demagnetization. Keep it.

  The permanent current superconducting magnet 10 </ b> C shown in the fourth embodiment can reduce the intrusion heat from the protective lead 34, and has the same effects as the superconducting magnet 10 shown in the first embodiment.

  In the permanent current superconducting magnet 10C, an ON-OFF switch 36 is attached to the protective circuit 35 to which the protective resistor 33 is connected as a switching means for turning on and off the protective circuit 35. When the high temperature superconducting coil 13 is excited or demagnetized, By turning off this ON-OFF switch 36, it is possible to prevent the current from being shunted to the protective resistor 33 during excitation and demagnetization.

  FIG. 7 is a schematic overall configuration diagram showing a fifth embodiment of a permanent current superconducting magnet according to the present invention.

  The permanent current superconducting magnet 10 </ b> D shown in this embodiment shows an example in which a protective resistor 33 and an ON-OFF switch 36 constituting a protective circuit are installed in the vacuum vessel 11. Since other configurations and operations are not different from the superconducting magnet 10C shown in the fourth embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  In the permanent current superconducting magnet 10D, when the ON-OFF switch 36 is installed in the protection circuit 37, the protection resistor 33 and the protection lead 34 are not heated during excitation or demagnetization. It is also possible to install 33 in a part having the same temperature as the radiation shield 12 or a part having the same temperature as the high temperature superconducting coil 13, that is, a low temperature part. By installing the protective resistor 33 in the low temperature part, the intrusion heat from the protective lead 34 can be reduced, and the same effects as those shown in the third embodiment can be achieved.

  FIG. 8 is an overall configuration diagram schematically showing a sixth embodiment of the permanent current superconducting magnet according to the present invention.

  In the permanent current superconducting magnet 10E shown in this embodiment, the cooling means 40 of the high temperature superconducting coil 13 may be constituted by a refrigeration cycle. The cooling means 40 is provided with a refrigerant flow path 41 for circulating a refrigerant such as He, Ne, etc., and the refrigerant flow path 41 is guided through the vacuum vessel 11 and the radiation shield 12 into the vacuum vessel 11 so as to be connected to the high-temperature superconducting coil 13. The high temperature superconducting coil 13 is provided so as to be cooled.

  In the permanent current superconducting magnet 10E shown in FIG. 8, the cooling means 40 of the high temperature superconducting coil 13 is constituted by a refrigeration cycle instead of conduction cooling by a refrigerator, and the refrigerant flow path 41 of the refrigeration means 40 is connected to the high temperature superconducting coil 13. Is provided, and the refrigerant is circulated in the refrigerant flow path 41 to be cooled. Since other configurations and operations are not different from the superconducting magnet 10B shown in the third embodiment, the same components are denoted by the same reference numerals and description thereof is omitted. The permanent current superconducting magnet excluding the cooling means 40 of the high-temperature superconducting coil 13 may be configured as shown in FIGS. 1, 4, 6 and 7.

  The permanent current superconducting magnet 10E shown in the sixth embodiment can attenuate the permanent current without quenching the high temperature superconducting coil 13 even if the temperature of the high temperature superconducting coil 13 rises. In addition to facilitating operation by separating the cooling means 40 for flowing the refrigerant and the current lead 23, the same effects as the effects described in the previous embodiment are achieved.

  In the permanent current superconducting magnet 10E, after the permanent current superconducting magnets 10 to 10D shown in the first to fifth embodiments are operated in the permanent current mode, the cooling means 40 and the current lead 22 are separated and operated. Etc. can be facilitated.

  FIG. 9 is an overall configuration diagram schematically showing a seventh embodiment of the permanent current superconducting magnet according to the present invention.

  The permanent current superconducting magnet 10F shown in this embodiment is provided with a refrigerant channel attaching / detaching part 44 in the cooling means 40 of the high temperature superconducting coil 13 so that the refrigerant channel 41 can be set to be freely separated from the main body side of the refrigeration cycle. In addition, a current lead attaching / detaching portion 45 is also provided at a current lead drawing portion from the permanent current circuit 16 so as to be freely separated from the excitation power source 23. Since other configurations and operations are not different from those shown in the first to fifth embodiments, the same components are denoted by the same reference numerals and description thereof is omitted.

  The permanent current superconducting magnet 10F shown in FIG. 9 is provided with a refrigerant flow channel attaching / detaching portion 44 in the cooling means 40 of the high temperature superconducting coil 13, disconnecting the refrigerant flow channel 41 from the main body side of the refrigeration cycle, and connecting the current lead 22 to the current lead. The detachable portion 45 can be separated from the excitation power source 23.

  This permanent current superconducting magnet 10F also has the same effects as the superconducting magnet 10E shown in the sixth embodiment.

  In the description of the embodiment of the present invention, the example in which the high-temperature superconducting coil accommodated in the vacuum vessel is cooled by the cooling means via the heat transfer means or the refrigerant flow path is shown. However, the shielding means is provided in the vacuum vessel. A closed container, a refrigerant such as He or Ne is accommodated in the closed container, the refrigerant is cooled by cooling means, and the high-temperature superconducting coil and the permanent current switch accommodated in the sealed container are cooled. Good. In this case, the permanent current switch may employ the switch structure described in Patent Documents 1 and 2.

BRIEF DESCRIPTION OF THE DRAWINGS The whole block diagram which shows 1st Embodiment of the permanent current superconducting magnet which concerns on this invention. The figure which shows the permanent current switch used for the permanent current superconducting magnet shown by FIG. Sectional drawing which shows the modification of the permanent current switch shown by FIG. The whole block diagram which shows 2nd Embodiment of the permanent current superconducting magnet which concerns on this invention. The whole block diagram which shows 3rd Embodiment of the permanent current superconducting magnet which concerns on this invention. The whole block diagram which shows 4th Embodiment of the permanent current superconducting magnet which concerns on this invention. The whole block diagram which shows 5th Embodiment of the permanent current superconducting magnet which concerns on this invention. The whole block diagram which shows 6th Embodiment of the permanent current superconducting magnet which concerns on this invention. The whole block diagram which shows 7th Embodiment of the permanent current superconducting magnet which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Permanent current superconducting magnet 11 Vacuum container 12 Radiation shield 13 High temperature superconducting coil 14 Permanent current switch 15 High temperature superconducting wire 16 Permanent current circuit 18 Refrigerator (cooling means)
19 Coil heat transfer means 20 Switch heat transfer means 22 Current lead (energization means)
23 Excitation power supply (energization means)
25 Superconducting conductor for permanent current switch 26 Substrate 27 High-temperature superconducting thin film 28, 29 Electrode 30 Metal protective layer 31, 35, 37 Coil protection circuit 33 Protection resistor 34 Protection lead 36 ON-OFF switch (switch means)

Claims (9)

A high-temperature superconducting coil housed in a vacuum vessel;
A permanent current switch thermally connected to the high temperature superconducting coil;
Heat insulating means for insulating the high temperature superconducting coil and the permanent current switch from an external environment;
Cooling means for cooling the high temperature superconducting coil and the permanent current switch;
Energizing means for exciting the high-temperature superconducting coil via a current lead;
A permanent current superconducting magnet, wherein a quench temperature of the permanent current switch is set lower than a quench temperature of a high temperature superconducting coil. The permanent current superconducting magnet according to claim 1, wherein a protective resistor is connected to a room temperature portion in parallel with the permanent current switch, and a protection circuit for the high temperature superconducting coil is provided. 2. The permanent current according to claim 1, wherein a protective resistor is provided in the permanent current circuit through a protective lead, the high-temperature superconducting coil is electrically connected using the protective lead, and a protective circuit for the high-temperature superconducting coil is provided. Superconducting magnet. 4. The permanent current superconducting magnet according to claim 2, wherein the protection circuit for the high-temperature superconducting coil is provided with a switch means capable of turning on and off a protective resistance. 5. The permanent current superconducting magnet according to claim 3, wherein the protective resistance is installed at a part having the same temperature as the heat insulating means in the vacuum vessel or a part having the same temperature as the high temperature superconducting coil. The permanent current superconducting magnet according to claim 1, wherein the cooling means and the energization means are provided detachably, and the cooling means and the energization means are operated in a disconnected state. 2. The permanent current superconducting device according to claim 1, wherein the permanent current switch uses a superconducting conductor in which a belt-like high-temperature superconducting thin film is formed on a metal plate or an insulating substrate, and the conductor width of the high-temperature superconducting thin film is adjustable. magnet. A superconducting conductor is formed by forming a strip-shaped high-temperature superconducting thin film on a metal plate or an insulating substrate, and the superconducting conductor can adjust the width of the high-temperature superconducting thin film, and the quench temperature can be adjusted. Characteristic permanent current superconducting switch. 9. The permanent current superconducting switch according to claim 8, further comprising a metal protective layer on the high temperature superconducting thin film.

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