accelerator

Abstract

To provide an accelerator capable of simplifying a cooling structure.SOLUTION: A coil vacuum vessel 24 encloses an acceleration space 20 in which charged particles are accelerated and the acceleration space 20 is maintained in a vacuum. The heat-generating devices are placed inside the coil vacuum vessel 24. A heat sink 61 for cooling the heat-generating devices is formed as a part of the coil vacuum vessel 24.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to an accelerator.

Background Art

[0002] In an accelerator such as a superconducting cyclotron or a superconducting synchrocyclotron, there are heat-generating devices in the beam acceleration space where charged particles are accelerated and shaped into a beam. Examples of heat-generating devices include high-voltage cables of high-frequency ion extraction devices for extracting a beam. Also, components that generate heat when a beam collides, such as a beam scraper for adjusting the beam size, are also heat-generating devices.

[0003] When the temperature of the heat-generating device rises, changes in the magnetic field distribution and deterioration of the vacuum degree in the accelerator may occur, which may cause deterioration of the beam quality. Therefore, it is necessary to appropriately cool the heat-generating device.

[0004] As a cooling method for cooling the heat-generating device, a method of directly cooling the heat-generating device by providing a pipe through which a cooling medium such as water passes in the vacuum region inside the accelerator can be considered. However, in this method, since various devices and wirings are installed inside the accelerator, the structure for routing the pipe becomes complicated, resulting in a problem of increased cost. There is also a risk that the cooling medium leaks from the pipe into the accelerator.

[0005] On the other hand, Patent Document 1 describes that a heat sink provided around a shielding film may be used as a cooling unit for cooling a shielding film disposed in the vacuum region inside the accelerator.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, Patent Document 1 does not describe specific methods for installing the heatsink, making it difficult to simplify the cooling structure.

[0008] The purpose of this disclosure is to provide an accelerator that can simplify the cooling structure. [Means for solving the problem]

[0009] An accelerator according to one aspect of the present disclosure is an accelerator for accelerating and ejecting charged particles, comprising: a vacuum vessel surrounding an acceleration space for accelerating the charged particles and creating a vacuum in the acceleration space; a heat-generating device disposed within the vacuum vessel; and a cooling structure for cooling the heat-generating device, wherein the cooling structure is formed as part of the vacuum vessel. [Effects of the Invention]

[0010] According to the present invention, it is possible to simplify the cooling structure. [Brief explanation of the drawing]

[0011] [Figure 1] This is a front view of an accelerator according to one embodiment of the present disclosure. [Figure 2] This is a top view of an accelerator according to one embodiment of the present disclosure. [Figure 3] This is a longitudinal cross-sectional view of an accelerator according to one embodiment of the present disclosure. [Figure 4] This is a top view of the configuration on the core splitting surface of an accelerator according to one embodiment of the present disclosure. [Figure 5] This is a diagram illustrating an example of a heat-generating device and its cooling method. [Figure 6] This is a diagram illustrating other examples of heat-generating devices and their cooling methods. [Figure 7] This figure shows an example of a heatsink. [Modes for carrying out the invention]

[0012] The embodiments of this disclosure will be described below with reference to the drawings.

[0013] Figure 1 is a front view of an accelerator according to one embodiment of the present disclosure, Figure 2 is a top view of an accelerator according to one embodiment of the present disclosure, and Figure 3 is a longitudinal cross-sectional view of an accelerator according to one embodiment of the present disclosure along line AA in Figure 2.

[0014] As shown in Figures 1 to 3, the accelerator 1 of this embodiment is an accelerator that accelerates charged particles and emits them as a beam (ion beam), such as a superconducting cyclotron or a superconducting synchrocyclotron. However, the accelerator 1 is not limited to these examples.

[0015] The accelerator 1 has a superconducting magnet 10 with an iron core. The superconducting magnet 10 with an iron core is a main magnetic field generator that generates the main magnetic field for circulating the beam, and has an iron core (return yoke) 11 that has a substantially cylindrical shape. The iron core 11 is configured to be separable into upper and lower halves by a core division surface P, which is a substantially horizontal surface passing through the substantially center in the vertical direction.

[0016] The iron core 11 is provided with support legs 12 that support the iron core 11, and a lifter 13 that raises and lowers the upper part of the iron core 11 in order to divide the iron core 11 into upper and lower halves. There may be multiple support legs 12.

[0017] As shown in Figure 3, an symmetrical acceleration space 20 is formed inside the iron core 11, with the iron core dividing surface P in between. In the acceleration space 20, a main magnetic field oriented vertically is generated by the iron core-equipped superconducting magnet 10, and the beam circulates within the acceleration space 20 due to this main magnetic field.

[0018] Also, inside the iron core 11, as shown in FIG. 3, two superconducting coils 21 for generating a main magnetic field are arranged substantially symmetrically with respect to the iron core dividing surface P. Each superconducting coil 21 is housed in a coil frame 22. The coil frame 22 is surrounded by a coil part shield plate 23 that shields radiant heat from the outside. Further, the superconducting coil 21, the coil frame 22, and the coil part shield plate 23 are enclosed in a coil part vacuum vessel 24 that keeps the inside in a vacuum state.

[0019] In addition, at the upper and lower parts of the iron core 11, refrigerators 25 for cooling the superconducting coil 21 to a temperature below the temperature at which the superconducting coil 21 exhibits perfect diamagnetism are provided. The refrigerator 25 provided at the upper part cools the superconducting coil 21 arranged above the iron core dividing surface P, and the refrigerator 25 provided at the lower part cools the superconducting coil 21 arranged above the iron core dividing surface P. In the present embodiment, four refrigerators 25 are provided, two at the top and two at the bottom, but the number of refrigerators 25 is not limited to this example.

[0020] The refrigerator 25 includes a refrigerator port part 26 that extends to the inside of the coil part vacuum vessel 24, and thermally couples to the superconducting coil 21 inside the coil part shield plate 23 through the refrigerator port part 26. The refrigerator port part 26 is surrounded by a port part shield plate 27 that shields radiant heat from the outside. Further, the port part shield plate 27 is enclosed in a port part vacuum vessel 28 that keeps the inside in a vacuum state.

[0021] The coil part vacuum vessel 24 and the port part vacuum vessel 28 are not only evacuated inside, but also used as a vacuum vessel that evacuates the space including the acceleration space 20 surrounded by the coil part vacuum vessel 24 and the port part vacuum vessel 28 to a vacuum state. This space is evacuated by a vacuum pump (not shown). Also, since the inside of the coil part vacuum vessel 24 and the port part vacuum vessel 28 is installed in a vacuum state, there is no need to connect to a vacuum pump.

[0022] FIGS. 4 to 6 are diagrams for explaining the heat generating devices in the accelerator 1 and the cooling structure for cooling the heat generating devices.

[0023] Figure 4 is a top view of the configuration on the core splitting surface P of accelerator 1. As shown in Figure 4, an acceleration space 20 is formed surrounded by a vacuum vessel (coil section vacuum vessel 24), and this acceleration space 20 has beam acceleration electrodes 30 that generate an accelerating electric field for accelerating a beam circulating in the acceleration space 20. The beam acceleration electrodes 30 are, for example, high-frequency accelerating cavities. As a result, the beam can be accelerated to the desired energy while circulating in the acceleration space 20.

[0024] Furthermore, the acceleration space 20 is equipped with a beam extraction device 50 that extracts the beam circulating in the acceleration space 20 to the outside, and a high-frequency kicker 55 that excites an electric field that disturbs the beam circulating in the acceleration space 20 and guides the beam to the beam extraction device 50. A coaxial cable 56 is connected to the high-frequency kicker 55 as a cable that supplies a drive signal to drive the high-frequency kicker 55.

[0025] The beam extraction device 50 generates heat when the beam collides with it, and the coaxial cable 56 generates heat due to the drive signal. Therefore, the beam extraction device 50 and the coaxial cable 56 become heat-generating devices. In addition, a cooling structure is formed in a part of the coil section vacuum container 24 to cool the heat-generating devices.

[0026] Figure 5 is a diagram illustrating the beam extraction equipment 50, which is a heat-generating device, and its cooling method, and Figure 6 is a diagram illustrating the coaxial cable 56, which is a heat-generating device, and its cooling method.

[0027] As shown in Figures 4 to 6, the accelerator 1 is provided with a plurality of ducts 60 for drawing out the coaxial cable 56 and the beam, respectively. In this embodiment, at least a portion of the wall surface of the duct 60 for drawing out the coaxial cable 56 is formed by a heat sink 61, which is a cooling structure. The heat sink 61 and the beam extraction equipment 50 are thermally coupled to each other via a heat transfer member 70. Furthermore, the coaxial cable 56 is thermally coupled to the heat sink 61 by being placed on the wall surface formed by the heat sink 61 in the duct 60.

[0028] Note that the beam extraction equipment 50 and coaxial cable 56 are examples of heat-generating equipment, and the heat-generating equipment is not limited to these, but may be other equipment that requires cooling. For example, the heat-generating equipment may include equipment for accelerating the beam, such as a beam acceleration electrode 30. In this embodiment, multiple heat-generating equipment (beam extraction equipment 50 and coaxial cable 56) are thermally coupled to the same heat sink 61, but separate heat sinks may be provided for each heat-generating equipment. Also, the heat sink 61 does not have to be formed in the duct 60, as long as it is formed as part of a vacuum container.

[0029] Figure 7 shows an example of a heatsink 61. Specifically, Figure 7(a) is a bottom view of the heatsink 61, Figure 7(b) is a right side view of the heatsink 61, and Figure 7(c) is a front view of the heatsink 61.

[0030] The heat sink 61 shown in Figure 7 has a supply port 62 through which water, which is a refrigerant (cooling medium) for cooling the heat-generating equipment, is supplied, a refrigerant flow path 63 through which the water supplied to the supply port 62 passes, and an outlet 64 for discharging the water that has flowed through the refrigerant flow path 63. In the example in Figure 7, the refrigerant flow path 63 is arranged in a meandering manner, but it is not limited to this example. Furthermore, the heat sink 61 is formed so that the supply port 62 and the outlet 64 are located on the outside of the vacuum container (24).

[0031] Furthermore, the heat sink 61 is composed of a substrate portion 65 in which a coolant flow path 63 is formed, and a cover portion 66 that covers the substrate portion 65. The substrate portion 65 and the cover portion 66 are joined together, for example, by welding.

[0032] As described above, according to this embodiment, the vacuum vessel (24) surrounds the acceleration space (20) for accelerating charged particles, and the acceleration space 20 is kept under vacuum. The heat-generating devices (50, 56) are placed inside the vacuum vessel (24). The cooling structure (61) for cooling the heat-generating devices (50, 56) is formed as part of the vacuum vessel (24). Therefore, it is not necessary to arrange piping or the like inside the vacuum vessel for cooling the heat-generating devices, thus simplifying the cooling structure for cooling the heat-generating devices.

[0033] Furthermore, in this embodiment, the vacuum vessel (24) has a duct (60), and the cooling structure (61) is formed as at least a part of the wall surface of the duct (60). In this case, the cooling structure can be easily formed as part of the vacuum vessel.

[0034] Furthermore, in this embodiment, the cooling structure (61) is a heat sink, particularly a heat sink having a refrigerant flow path (63) through which the refrigerant passes, and the refrigerant supply port 62 and discharge port 64 are provided on the outside of the vacuum vessel (24). This makes it possible to easily supply and discharge the refrigerant. It also makes it possible to further suppress the leakage of refrigerant into the vacuum vessel.

[0035] Furthermore, in this embodiment, multiple heat-generating devices (50, 56) are thermally coupled to a single heat sink (61). In this case, the cooling structure can be further simplified.

[0036] Furthermore, in this embodiment, the heat-generating device is the beam extraction device (50), and the beam extraction device (50) and the cooling structure (61) are thermally coupled via a heat transfer member (70). This makes it possible to properly cool the beam extraction device (50).

[0037] Furthermore, in this embodiment, the heat-generating device is the coaxial cable (56) of the high-frequency kicker (55), and the coaxial cable (56) is arranged on the cooling structure (61). Therefore, the coaxial cable (56) can be easily cooled.

[0038] The embodiments of the Disclosure described above are illustrative for illustrative purposes and are not intended to limit the scope of the Disclosure to those embodiments only. Those skilled in the art can implement the Disclosure in various other forms without departing from the scope of the Disclosure. [Explanation of Symbols]

[0039] 1: Accelerator 10: Superconducting magnet with iron core 11: Iron core 12: Support legs 13: Lifter 20: Acceleration space 21: Superconducting coil 22: Coil frame 23: Coil section shield plate 24: Coil section vacuum vessel 25: Refrigerator 26: Refrigerator port section 27: Port section shield plate 28: Port section vacuum vessel 30: Beam acceleration electrode 50: Beam extraction equipment 55: High-frequency kicker 56: Coaxial cable 60: Duct 61: Heat sink 62: Supply port 63: Refrigerant flow path 64: Discharge port 65: Substrate section 66: Cover section 70: Heat transfer material

Claims

1. An accelerator that accelerates and emits charged particles, A vacuum vessel surrounds the acceleration space for accelerating the charged particles and creates a vacuum in the acceleration space, A heating device is placed inside the vacuum container, It has a cooling structure for cooling the heat-generating equipment, The cooling structure is formed as part of the vacuum vessel, The vacuum vessel has a duct, The cooling structure is formed as at least a portion of the wall surface of the duct, in an accelerator.

2. The accelerator according to claim 1, wherein the cooling structure is a heat sink.

3. The heat sink comprises a supply port for supplying refrigerant, a refrigerant flow path for passing the refrigerant supplied to the supply port, and an outlet for discharging the refrigerant that has flowed through the refrigerant flow path. The accelerator according to claim 2, wherein the supply port and the discharge port are provided on the outside of the vacuum vessel.

4. The accelerator according to claim 2, wherein a plurality of the heat-generating devices are thermally coupled to the same heat sink.

5. The aforementioned heating device is an extraction device for extracting the charged particles to the outside, The accelerator according to claim 1, wherein the extraction device and the cooling structure are thermally coupled via a heat transfer member.

6. The heating device is a cable that supplies a drive signal to drive a high-frequency kicker that guides the charged particles to an extraction device for extracting the charged particles to the outside. The accelerator according to claim 1, wherein the cable is arranged on the cooling structure.

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