JP6580501B2 - Superconducting cyclotron and superconducting electromagnet - Google Patents

Description

  The present invention relates to a superconducting cyclotron and a superconducting electromagnet.

  Conventionally, a superconducting electromagnet including a pair of magnetic poles, a coil unit having a pair of superconducting coils provided so as to surround each of the pair of magnetic poles, and a power supply unit that supplies power to the coil unit is used. A superconducting cyclotron is known (for example, Patent Document 1).

  In such a superconducting cyclotron, a strong magnetic force may act between each superconducting coil and an iron member constituting the cyclotron. Therefore, in order to prevent the superconducting coil from being damaged by such a strong force acting on each superconducting coil, the superconducting coils are connected to each other to cancel the forces acting on each superconducting coil. Has been done.

  Here, when quenching occurs in the coil portion, the balance of the forces acting on each superconducting coil is lost and the forces are not canceled out, and the superconducting coils may be damaged by the strong force acting on each superconducting coil. For this reason, when quenching occurs, it is desirable to quickly reduce the magnetic force acting on each superconducting coil. Therefore, it is known to provide a protection circuit provided with a resistor for quickly attenuating the current flowing through each superconducting coil in the power supply unit.

JP 2014-241217 A

  By the way, in such a superconducting cyclotron, in order to accurately adjust the strength and direction of the magnetic field formed between the pair of magnetic poles, the magnitude of the current flowing through each superconducting coil is individually determined for each superconducting coil. To be controlled. For this reason, even if quenching occurs in the coil section, the current flowing through each superconducting coil cannot be uniformly attenuated. For this reason, since the protection circuit is provided individually for each superconducting coil, a difference occurs in the magnitude of the current flowing through each superconducting coil when a quench occurs. Therefore, a difference occurs for each superconducting coil in the time until the current sufficiently attenuates due to the resistance of the protection circuit, and there is a possibility that the force acting on each superconducting coil cannot be sufficiently suppressed.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a superconducting cyclotron and a superconducting electromagnet that can suppress the force acting on the superconducting coil when quenching occurs. To do.

  The superconducting cyclotron of the present invention is provided between a pair of magnetic poles, an acceleration electrode that is disposed between the pair of magnetic poles, generates an electric field for accelerating charged particles, and surrounds each of the pair of magnetic poles. A coil unit having one superconducting coil and a second superconducting coil, and a power supply unit for supplying power to the coil unit, wherein the first superconducting coil and the second superconducting coil are connected in series to supply power The first part is connected to one end side of the coil part and the negative side is connected to the other end side of the coil part, and the positive side is connected to one end side of the second superconducting coil. From the second power source whose negative side is connected to the other end side of the second superconducting coil and the first branch point provided between the positive side of the first power source and one end side of the coil section, the first power source Second branch provided between the negative side and the other end side of the coil portion So that the first power supply is connected in parallel with the coil unit and between the positive side of the first power supply and the first branch point, or the negative side of the first power supply and the second power supply. And a circuit breaker disposed between the branch point and capable of interrupting a current flowing through the first power source.

  In this superconducting cyclotron, power is supplied to the first superconducting coil and the second superconducting coil by the first power source, and power is supplied to the second superconducting coil by the second power source. Therefore, it is possible to individually control the magnitude of the current flowing through each superconducting coil, and to accurately adjust the strength and direction of the magnetic field formed between the pair of magnetic poles. it can. Moreover, when quenching occurs in the coil section, a closed circuit is formed in which the resistor, the first superconducting coil, and the second superconducting coil are connected in series by operating the circuit breaker. Therefore, since the current flowing through each superconducting coil of the coil portion flows through a closed circuit via a resistor, the current flowing through each superconducting coil is uniformly attenuated. As described above, in each superconducting coil, there is no difference in the time until the current is sufficiently attenuated due to the resistance of the protection circuit. Therefore, when a quench occurs, the force acting on the superconducting coil can be suppressed.

  In the superconducting cyclotron according to the present invention, the coil unit includes a quench detection unit that detects that quenching has occurred in the coil unit, and the power supply unit detects that quenching has occurred in the coil unit. In addition, a control unit that operates the circuit breaker so as to interrupt the current flowing through the first power source may be provided. In this case, when quenching occurs in the coil section, the current flowing through the first power supply can be quickly cut off. Therefore, when quenching occurs, the force acting on the superconducting coil can be quickly suppressed.

  In the superconducting cyclotron of the present invention, the coil portion further includes a third superconducting coil and a fourth superconducting coil provided so as to surround the pair of magnetic poles, respectively, and the first superconducting coil and the second superconducting coil. The third superconducting coil and the fourth superconducting coil are connected in series, and the power supply unit has a positive side connected to one end of the third superconducting coil and a negative side connected to the other end of the third superconducting coil. And a fourth power source having a positive side connected to one end side of the fourth superconducting coil and a negative side connected to the other end side of the fourth superconducting coil. May be. In this case, the strength and direction of the magnetic field generated between the pair of magnetic poles can be adjusted with high accuracy.

  In the superconducting cyclotron of the present invention, the coil unit may have a plurality of pairs of third superconducting coils and fourth superconducting coils. In this case, the strength and direction of the magnetic field generated between the pair of magnetic poles can be adjusted with high accuracy.

  The superconducting electromagnet of the present invention includes a pair of magnetic poles, a coil part having a first superconducting coil and a second superconducting coil provided so as to surround each of the pair of magnetic poles, and electric power for supplying electric power to the coil part. And a first superconducting coil and a second superconducting coil are connected in series, and the power supply unit has a positive side connected to one end side of the coil unit and a negative side connected to the other end side of the coil unit. A first power source connected to the second superconducting coil, a positive power source connected to one end of the second superconducting coil, and a negative power source connected to the other end of the second superconducting coil; From the first branch point provided between the positive side of the coil and one end side of the coil part to the second branch point provided between the negative side of the first power source and the other end side of the coil part The resistance connected in parallel with the coil portion with respect to the first power supply, and the positive side of the first power supply Between the first branching point, or disposed between the negative and the second branch point of the first power source, a circuit breaker capable of interrupting the current flowing through the first power supply may have.

  In this superconducting electromagnet, power is supplied to the first superconducting coil and the second superconducting coil by the first power source, and power is supplied to the second superconducting coil by the second power source. Therefore, it is possible to individually control the magnitude of the current flowing through each superconducting coil, and to accurately adjust the strength and direction of the magnetic field formed between the pair of magnetic poles. it can. Moreover, when quenching occurs in the coil section, a closed circuit in which the resistor, the first superconducting coil, and the second superconducting coil are connected in series is formed by operating the circuit breaker. Therefore, since the current flowing through each superconducting coil of the coil portion flows through a closed circuit via a resistor, the current flowing through each superconducting coil is uniformly attenuated. As described above, in each superconducting coil, there is no difference in the time until the current is sufficiently attenuated due to the resistance of the protection circuit. Therefore, when a quench occurs, the force acting on the superconducting coil can be suppressed.

  According to the present invention, it is possible to suppress the force acting on the superconducting coil when quenching occurs.

It is sectional drawing which shows the structure of the superconducting cyclotron which concerns on embodiment. It is a circuit diagram of a superconducting cyclotron according to an embodiment. It is a circuit diagram of a superconducting cyclotron according to a modification.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same part or an equivalent part, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 1, the superconducting cyclotron 1 according to the present embodiment supplies charged particles from an ion source (not shown) into the acceleration space G and accelerates the charged particles in the acceleration space G to charge particles. It is a horizontal circular accelerator that outputs a beam. Examples of the charged particles include protons and heavy particles (heavy ions). The superconducting cyclotron 1 is used as an accelerator for charged particle beam therapy, for example.

  In this superconducting cyclotron 1, the charged particle beam that draws a circular orbit in the acceleration space G is continuously accelerated, so isochronism (the time required for one round is equal regardless of the size of the radius of the circular orbit). It is necessary to control the strength and direction of the magnetic field to ensure it.

  The superconducting cyclotron 1 includes a superconducting electromagnet 5, a de-electrode (acceleration electrode) 2, and vertical load supports 11 and 12 in addition to the ion source. Superconducting electromagnet 5 has a pair of magnetic poles 3, 4, yoke 6, coil portion 7, coil support frame 9, vacuum vessel 10, and power supply portion 20. The coil unit 7 includes a first superconducting coil 7A, a second superconducting coil 7B, and a quench detecting unit 8 (see FIG. 2).

  The magnetic poles 3 and 4 are spaced apart in the direction of the central axis C of the first superconducting coil 7A and the second superconducting coil 7B. In the superconducting cyclotron 1, the central axis C direction is arranged along the vertical direction. The magnetic pole 3 is an upper magnetic pole disposed above the acceleration space G, and the magnetic pole 4 is a lower magnetic pole disposed below the acceleration space G. A de-electrode 2 is disposed between the magnetic poles 3 and 4. The de-electrode 2 generates an electric field for accelerating charged particles by applying a high frequency.

  The yoke 6 is a hollow disk-shaped block, in which the magnetic poles 3 and 4 and the vacuum vessel 10 are arranged. The yoke 6 includes a cylindrical portion 6a, a top portion 6b formed so as to close one opening of the cylindrical portion 6a, and a bottom portion 6c formed so as to close the other opening of the cylindrical portion 6a. The yoke 6 is for preventing the magnetic field generated by the first superconducting coil 7A, the second superconducting coil 7B, and the magnetic poles 3 and 4 from leaking outside.

  The first superconducting coil 7A and the second superconducting coil 7B are provided so as to surround each of the pair of magnetic poles 3 and 4. The first superconducting coil 7A and the second superconducting coil 7B are arranged side by side in the central axis C direction. The first superconducting coil 7 </ b> A is wound so as to cover the outer periphery of the magnetic pole 3, and the second superconducting coil 7 </ b> B is wound so as to cover the outer periphery of the magnetic pole 4. The first superconducting coil 7A and the second superconducting coil 7B, for example, are not provided with an inner frame (or inner winding frame) on the inner peripheral side, and the inner periphery of the coil (wire and adhesive for fixing the wire) An air-core coil whose surface is not bonded or fixed by another member.

  The first superconducting coil 7A and the second superconducting coil 7B are cooled by a refrigerator (not shown) to be in a superconducting state, and are supplied with electric power by a power supply unit 20 described later. The first superconducting coil 7A and the second superconducting coil 7B are connected in series.

  The quench detection unit 8 shown in FIG. 2 detects that a quench has occurred in the superconducting coil in the coil unit 7. The quench detection unit 8 includes a first quench detector 8A that detects the occurrence of quench in the first superconducting coil 7A, a second quench detector 8B that detects the occurrence of quench in the second superconducting coil 7B, and a first A quench detector controller 8M that controls the operation of the quench detector 8A and the second quench detector 8B. Since the first quench detector 8A and the second quench detector 8B have the same configuration, the configuration of the first quench detector 8A will be described below.

  The first quench detector 8A divides the first superconducting coil 7A into two regions, one end side and the other end side, and measures the voltage in each region. The first quench detector 8 </ b> A divides the first superconducting coil 7 </ b> A at a position where the voltage in each region in a state where no quench occurs is substantially equal, and monitors the change in the voltage difference in each region. When a quench occurs in the first superconducting coil 7A, the resistance value at the site where the quench occurs increases. For this reason, the first quench detector 8A detects that a quench has occurred in the first superconducting coil 7A when the voltage difference being monitored changes by a predetermined value or more.

  When the first quench detector 8A or the second quench detector 8B detects the occurrence of a quench, the quench detector control device 8M indicates that the quench has occurred in the coil unit 7 in the control unit 25 of the power supply unit 20. To notify. Details of the control unit 25 will be described later.

  Returning to FIG. 1, the coil support frame 9 includes a side plate portion 9a covering the outer peripheral surface of the first superconducting coil 7A, an upper ring member 9b covering the upper surface of the first superconducting coil 7A, and a second superconducting coil 7B. A side plate portion 9c that covers the outer peripheral surface, a lower ring member 9d that covers the lower surface of the second superconducting coil 7B, and an intermediate portion 9e that connects the upper and lower side plate portions 9a and 9c. The coil support frame 9 is formed over the entire circumference in the circumferential direction of the first superconducting coil 7A and the second superconducting coil 7B.

  The upper ring member 9b is formed so as to protrude radially inward from the upper end portion of the side plate portion 9a. The upper ring member 9b has an annular plate shape, and the plate thickness direction of the upper ring member 9b is arranged along the central axis C direction.

  The lower ring member 9d is formed so as to protrude radially inward from the lower end portion of the side plate portion 9c. The lower ring member 9d has an annular plate shape, and the thickness direction of the lower ring member 9d is arranged along the central axis C direction.

  The radial width of the intermediate portion 9e corresponds to the radial width of the first superconducting coil 7A and the second superconducting coil 7B. The cross section of the intermediate part 9e has a rectangular shape, for example. The upper surface of the intermediate portion 9e is in contact with the lower surface of the first superconducting coil 7A, and the lower surface of the intermediate portion 9e is in contact with the upper surface of the second superconducting coil 7B. Moreover, the upper surface of the intermediate part 9e is joined to the side plate part 9a, and the lower surface of the intermediate part 9e is joined to the side plate part 9c. The joining between the intermediate portion 9e and the side plate portion 9a may be bolt joining or other joining methods such as welding. Similarly, the joining of the intermediate portion 9e and the side plate portion 9c may be bolt joining or other joining methods such as welding.

  With such a configuration, the intermediate portion 9e connects the first superconducting coil and the second superconducting coil to each other. As a result, the strong magnetic force acting between each of the first superconducting coil 7A and the second superconducting coil 7B and, for example, the iron yoke 6 is offset.

  The vacuum vessel 10 accommodates the first superconducting coil 7A, the second superconducting coil 7B, and the coil support frame 9. The vacuum vessel 10 is connected to a refrigerator for cooling the first superconducting coil 7A and the second superconducting coil 7B. The refrigerator is, for example, a GM refrigerator (Gifford-McMahon cooler), and can cool the first superconducting coil 7A and the second superconducting coil 7B to, for example, 4K. In addition, a refrigerator is not limited to GM refrigerator, For example, a Stirling refrigerator and other refrigerators may be used.

  The vertical load supports 11 and 12 support the coil support frame 9 and adjust the position of the coil support frame 9 in the direction of the central axis C. The vertical load supports 11 and 12 are fixed relative to the yoke 6 and support the coil support frame 9 from the central axis C direction. The vertical load supports 11 and 12 are arranged so as to sandwich the coil support frame 9 as a pair of upper and lower sides, and support the coil support frame 9 by pulling the coil support frame 9 in opposite directions. A plurality of the vertical load supports 11 and 12 are arranged in the circumferential direction of the coil support frame 9. The plurality of vertical load supports 11 and 12 are arranged at equal intervals in the circumferential direction of the coil support frame 9.

  As shown in FIG. 2, the power supply unit 20 supplies power to the coil unit 7. The power supply unit 20 includes a first power supply 21 </ b> A, a second power supply 21 </ b> B, a protective resistor (resistance) 23, a circuit breaker 24, and a control unit 25.

  The first power source 21 </ b> A is a power source for supplying power to the entire coil unit 7. The first power source 21 </ b> A has a positive side P <b> 1 connected to one end side S <b> 1 of the coil unit 7 and a negative side N <b> 1 connected to the other end side S <b> 2 of the coil unit 7. The one end side S1 and the other end side S2 of the coil unit 7 include a plurality of superconducting coils connected in series (here, two superconducting coils including a first superconducting coil 7A and a second superconducting coil 7B). It is the both ends side of the coil part 7. FIG.

  The second power source 21 </ b> B is a power source for supplying power to the second superconducting coil 7 </ b> B in the coil unit 7. The second power supply 21B has a positive side P2 connected to one end side S3 of the second superconducting coil 7B and a negative side N2 connected to the other end side S4 of the second superconducting coil 7B. One end side S3 and the other end side S4 of the second superconducting coil 7B are both end sides of the second superconducting coil 7B.

  The protective resistor 23 is a resistor for attenuating the current flowing through the coil unit 7. The protective resistor 23 is connected in parallel with the coil unit 7 with respect to the first power source 21A. Specifically, on the circuit connecting the positive side P1 of the first power supply 21A and the one end side S1 of the coil section 7, a first branch point 22A for branching another circuit from the circuit is provided. On the circuit connecting the negative side N1 of the first power supply 21A and the other end side S2 of the coil section 7, a second branch point 22B for branching another circuit from the circuit is provided. The circuit branched from the first branch point 22A and the circuit branched from the second branch point 22B are connected via a protective resistor 23. That is, the protective resistor 23 is connected in parallel to the coil unit 7 with respect to the first power source 21A so as to connect the first branch point 22A to the second branch point 22B.

  The circuit breaker 24 is a circuit breaker for interrupting the current flowing through the first power source 21A. The circuit breaker 24 performs an operation of breaking / connecting according to a command from the control unit 25 described later. The circuit breaker 24 is disposed between the positive side P1 of the first power source 21A and the first branch point 22A. By arranging the circuit breaker 24 at such a position, when the circuit breaker 24 blocks the current flowing through the first power source 21A, the protective resistor 23, the first superconducting coil 7A, and the second superconducting coil 7B are in series with each other. A closed circuit connected to is formed. The circuit breaker 24 may be disposed between the negative side N1 of the first power supply 21A and the second branch point 22B.

  The control unit 25 controls the operation of the power supply unit 20. In particular, when the quench detector control device 8M is notified from the quench detector control device 8M that the quench has occurred when the first quench detector 8A or the second quench detector 8B detects the occurrence of the quench, The control unit 25 operates the circuit breaker 24 so as to interrupt the current flowing through the first power source 21A.

  Next, the operation of the superconducting cyclotron 1 will be described.

  In superconducting cyclotron 1, first power supply 21A supplies power to first superconducting coil 7A and second superconducting coil 7B. The second power supply 21B supplies power to the second superconducting coil 7B. This allows different currents to flow through the first superconducting coil 7A and the second superconducting coil 7B, so that the strength of the magnetic field formed between the pair of magnetic poles 3 and 4 and The direction can be adjusted with high accuracy.

  When a current flows through the first superconducting coil 7A and the second superconducting coil 7B to form a magnetic field, a strong magnetic force acts between each superconducting coil and an iron member such as the yoke 6. At this time, the first superconducting coil 7A and the second superconducting coil 7B are connected to each other via the intermediate portion 9e of the coil support frame 9, and the first superconducting coil 7A and the second superconducting coil 7B are connected to each other. Magnetic forces act on each of the first superconducting coil 7A and the second superconducting coil 7B because the magnetic force acts in a balanced manner (that is, substantially plane-symmetric with respect to a plane perpendicular to the central axis C). Power offsets.

  Here, when a quench occurs in the coil unit 7, the resistance value of the superconducting coil in which the quench has occurred increases, and therefore when the quench occurs, a difference occurs in the magnitude of the current flowing through each superconducting coil. For this reason, the magnetic force acting on each of the first superconducting coil 7A and the second superconducting coil 7B does not cancel out.

  In the superconducting cyclotron 1, when a quench occurs in the coil unit 7, the quench detection unit 8 detects that the quench has occurred. Then, the control unit 25 instructs the circuit breaker 24 to execute an operation for interrupting the current.

  By operating the circuit breaker 24 and cutting off the current flowing through the first power source 21A, a closed circuit is formed in which the protective resistor 23, the first superconducting coil 7A and the second superconducting coil 7B are connected in series with each other. The Therefore, since the current flowing through each superconducting coil of the coil portion 7 flows through a closed circuit via a resistor, the current flowing through each superconducting coil is uniformly attenuated.

  As described above, in the superconducting cyclotron 1, electric power is supplied to the first superconducting coil 7A and the second superconducting coil 7B by the first power source 21A, and to the second superconducting coil 7B by the second power source 21B. Power is supplied. Accordingly, it is possible to individually control the magnitude of the current flowing through each superconducting coil, and accurately adjust the strength and direction of the magnetic field formed between the pair of magnetic poles 3 and 4. can do. In addition, when a quench occurs in the coil unit 7, by operating the circuit breaker 24, a closed circuit in which the protective resistor 23, the first superconducting coil 7A, and the second superconducting coil 7B are connected in series with each other is formed. It is formed. Therefore, since the current flowing through each superconducting coil of the coil unit 7 flows through a closed circuit via the protective resistor 23, the current flowing through each superconducting coil is uniformly attenuated. As described above, in each superconducting coil, there is no difference in the time until the current is sufficiently attenuated due to the resistance of the protection circuit. Therefore, when a quench occurs, the force acting on the superconducting coil can be suppressed.

  In the superconducting cyclotron 1, the coil unit 7 includes a quench detection unit 8 that detects that quenching has occurred in the coil unit 7, and the power supply unit 20 has the quench detection unit 8 that quenching has occurred in the coil unit 7. Is detected, the controller 25 is provided to operate the circuit breaker 24 so as to interrupt the current flowing through the first power source 21A. For this reason, when quenching occurs in the coil section 7, the current flowing through the first power source 21A can be quickly cut off. Therefore, when quenching occurs, the force acting on the superconducting coil can be quickly suppressed.

  In the superconducting electromagnet 5, power is supplied to the first superconducting coil 7A and the second superconducting coil 7B by the first power source 21A, and power is supplied to the second superconducting coil 7B by the second power source 21B. The Accordingly, it is possible to individually control the magnitude of the current flowing through each superconducting coil, and accurately adjust the strength and direction of the magnetic field formed between the pair of magnetic poles 3 and 4. can do. Further, when quenching occurs in the coil unit 7, the circuit breaker 24 is operated to form a closed circuit in which the protective resistor 23, the first superconducting coil 7A, and the second superconducting coil 7B are connected in series with each other. Is done. Therefore, since the current flowing through each superconducting coil of the coil unit 7 flows through a closed circuit via the protective resistor 23, the current flowing through each superconducting coil is uniformly attenuated. As described above, in each superconducting coil, there is no difference in the time until the current is sufficiently attenuated due to the resistance of the protection circuit. Therefore, when a quench occurs, the force acting on the superconducting coil can be suppressed.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment.

  For example, as shown in FIG. 3, the superconducting cyclotron 1 may include a plurality of pairs of superconducting coils. Specifically, in the superconducting cyclotron 1, the coil unit 7 further includes a third superconducting coil 7C and a fourth superconducting coil 7D provided so as to surround the pair of magnetic poles 3 and 4, respectively. The conducting coil 7A, the second superconducting coil 7B, the third superconducting coil 7C, and the fourth superconducting coil 7D may be connected in series. At this time, the power supply unit 20 has a positive side P3 connected to one end S5 of the third superconducting coil 7C and a negative side N3 connected to the other end S6 of the third superconducting coil 7C. A third power source 21C, a fourth power source 21D having a positive side P4 connected to one end S7 of the fourth superconducting coil 7D and a negative side N4 connected to the other end S8 of the fourth superconducting coil 7D; You may have. In this case, the strength and direction of the magnetic field generated between the pair of magnetic poles 3 and 4 can be adjusted with high accuracy.

  Moreover, in the superconducting cyclotron 1, the coil unit 7 may have a plurality of pairs of the third superconducting coil 7C and the fourth superconducting coil 7D. That is, the coil unit 7 may include two or more third superconducting coils 7C and two or more fourth superconducting coils 7D that are the same number as the third superconducting coils 7C. In this case, the strength and direction of the magnetic field generated between the pair of magnetic poles 3 and 4 can be adjusted with high accuracy.

  In the above embodiment, the superconducting electromagnet 5 is described as being used in the superconducting cyclotron 1, but the superconducting electromagnet 5 is not limited to this, and the superconducting electromagnet 5 is used in a silicon single crystal pulling apparatus or the like by the MRI or MCZ method. May be.

  3, 4 ... Magnetic pole, 2 ... Di electrode (acceleration electrode), 7 ... Coil part, 7A ... 1st superconducting coil, 7B ... 2nd superconducting coil, 20 ... Power supply part, 21A ... 1st power supply, 21B ... 2nd power supply, 22A ... 1st branch point, 22B ... 2nd branch point, 23 ... Protection resistance (resistance), 24 ... Circuit breaker.

Claims (5)

A pair of magnetic poles;
An accelerating electrode disposed between the pair of magnetic poles for generating an electric field for accelerating charged particles;
A coil portion having a first superconducting coil and a second superconducting coil provided so as to surround each of the pair of magnetic poles;
A power supply unit for supplying power to the coil unit,
The first superconducting coil and the second superconducting coil are connected in series;
The power supply unit
A first power source having a positive side connected to one end side of the coil portion and a negative side connected to the other end side of the coil portion;
A second power source having a positive side connected to one end of the second superconducting coil and a negative side connected to the other end of the second superconducting coil;
From a first branch point provided between the positive side of the first power source and the one end side of the coil portion, between the negative side of the first power source and the other end side of the coil portion. A resistor connected in parallel to the coil unit with respect to the first power supply so as to connect to the second branch point provided and to be connected only at the first branch point and the second branch point. When,
Disposed between the positive side of the first power source and the first branch point, or between the negative side of the first power source and the second branch point, and interrupts the current flowing through the first power source A superconducting cyclotron having a possible circuit breaker. The coil unit includes a quench detection unit that detects that quenching has occurred in the coil unit,
The power supply unit includes a control unit that operates the circuit breaker so as to cut off a current flowing through the first power source when the quench detection unit detects that a quench has occurred in the coil unit. Item 2. The superconducting cyclotron according to Item 1. The coil portion further includes a third superconducting coil and a fourth superconducting coil provided so as to surround the pair of magnetic poles, respectively.
The first superconducting coil, the second superconducting coil, the third superconducting coil, and the fourth superconducting coil are connected in series,
The power supply unit
A third power source having a positive side connected to one end of the third superconducting coil and a negative side connected to the other end of the third superconducting coil;
The super power source according to claim 1, further comprising: a fourth power source having a positive side connected to one end side of the fourth superconducting coil and a negative side connected to the other end side of the fourth superconducting coil. Conductive cyclotron.   The superconducting cyclotron according to claim 3, wherein the coil section includes a plurality of pairs of the third superconducting coil and the fourth superconducting coil. A pair of magnetic poles;
A coil portion having a first superconducting coil and a second superconducting coil provided so as to surround each of the pair of magnetic poles;
A power supply unit for supplying power to the coil unit,
The first superconducting coil and the second superconducting coil are connected in series;
The power supply unit
A first power source having a positive side connected to one end side of the coil portion and a negative side connected to the other end side of the coil portion;
A second power source having a positive side connected to one end of the second superconducting coil and a negative side connected to the other end of the second superconducting coil;
From a first branch point provided between the positive side of the first power source and the one end side of the coil portion, between the negative side of the first power source and the other end side of the coil portion. A resistor connected in parallel to the coil unit with respect to the first power supply so as to connect to the second branch point provided and to be connected only at the first branch point and the second branch point. When,
Disposed between the positive side of the first power source and the first branch point, or between the negative side of the first power source and the second branch point, and interrupts the current flowing through the first power source And a possible circuit breaker.

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