Superconducting accelerating cavity tube, superconducting accelerator, and method of manufacturing superconducting accelerating cavity tube

Abstract

To provide a superconducting accelerating cavity tube, a superconducting accelerator, and a method of manufacturing the superconducting accelerating cavity tube, which can be reduced in the manufacturing cost while securing sufficient strength.SOLUTION: One aspect of a superconducting accelerating cavity tube is a superconducting accelerating cavity tube for accelerating charged particles along a beam axis, and comprises a tube body extending in the axial direction of the beam axis. The tube body has: a reinforcement layer made of stainless steel; a substrate layer bonded to an inner surface of the reinforcement layer; and a superconducting layer formed on an inner surface of the substrate layer.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a superconducting acceleration cavity tube, a superconducting acceleration device, and a method for manufacturing a superconducting acceleration cavity tube. [Background technology]

[0002] As a device for accelerating charged particles such as electrons or protons, an acceleration cavity tube is known that applies a resonated electric field to the charged particles to accelerate them. As an example of an acceleration cavity tube, a superconducting acceleration cavity tube using a superconducting material is known. Since a superconducting acceleration cavity tube has a superconducting layer on its inner surface, power loss during acceleration of charged particles is significantly reduced. Patent Document 1 discloses that a film of a superconducting material such as magnesium boride (MgB2) is formed on the inner surface of a base layer made of copper or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-76131 A Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, a specific metal material such as copper is selected as the material for the substrate layer on which the superconducting layer is formed, in consideration of adhesion with the superconducting layer. In addition, the substrate layer is surrounded by a refrigerant such as liquid helium for cooling the superconducting layer. For this reason, in conventional superconducting accelerating cavity tubes, it was necessary to increase the thickness of the substrate layer in order to ensure sufficient strength against the pressure of the refrigerant. This resulted in a problem of increased material costs for the substrate layer and increased manufacturing costs for the superconducting accelerating cavity tubes.

[0005] In view of the above circumstances, an object of the present disclosure is to provide a superconducting acceleration cavity tube, a superconducting acceleration device, and a method for manufacturing a superconducting acceleration cavity tube that can reduce manufacturing costs while ensuring sufficient strength. [Means for solving the problem]

[0006] One aspect of a superconducting acceleration cavity tube according to the present disclosure is a superconducting acceleration cavity tube that accelerates charged particles along a beam axis, and includes a tube body extending in the axial direction of the beam axis, the tube body having a reinforcing layer made of stainless steel, a base layer joined to an inner surface of the reinforcing layer, and a superconducting layer formed on the inner surface of the base layer.

[0007] One aspect of a superconducting acceleration device according to the present disclosure includes the above-mentioned superconducting acceleration cavity tube, and a pressure vessel that houses the superconducting acceleration cavity tube and is filled with a refrigerant that contacts the outer surface of the reinforcing layer.

[0008] One aspect of the method for manufacturing a superconducting acceleration cavity tube according to the present disclosure is a method for manufacturing a superconducting acceleration cavity tube comprising a tube main body extending in the axial direction of a beam axis, the tube main body having a reinforcing layer made of stainless steel, a base layer joined to the inner surface of the reinforcing layer, and a superconducting layer formed on the inner surface of the base layer, the method including a clad material forming process for forming a clad material of the reinforcing layer and the base layer by bonding the stainless steel and a material constituting the base layer under heating and pressure, and a tube forming process for forming the clad material into a tubular shape with the base layer on the inside. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a superconducting acceleration cavity tube, a superconducting acceleration device, and a method for manufacturing a superconducting acceleration cavity tube, which can reduce manufacturing costs while ensuring sufficient strength. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view of a superconducting accelerator device according to an embodiment. [Diagram 2] 1 is a perspective view of a superconducting acceleration cavity tube according to an embodiment; [Diagram 3] FIG. 2 is a partial cross-sectional view of a pipe body according to an embodiment. [Figure 4]4 is a flowchart showing a method for manufacturing a superconducting acceleration cavity tube according to an embodiment. [Diagram 5] FIG. 2 is a schematic diagram of a clad material according to an embodiment. [Figure 6] 5A to 5C are schematic diagrams illustrating a pipe forming process according to an embodiment. [Figure 7] 5A to 5C are schematic diagrams illustrating a film forming process according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Note that the scope of the present disclosure is not limited to the following embodiment, and can be arbitrarily changed within the scope of the technical idea of ​​the present disclosure. In addition, in the following drawings, the scale and number of each structure may be different from the scale and number of the actual structure in order to make each configuration easier to understand. In addition, in the following description, the direction parallel to the beam axis J shown in FIG. 1 may be simply called the axial direction, and the radial direction relative to the beam axis J may be simply called the radial direction.

[0012] <Superconducting accelerator> FIG. 1 is a schematic cross-sectional view of a superconducting accelerator device 1 according to the present embodiment. The superconducting acceleration cavity 10 accelerates the charged particles along the beam axis J. The superconducting acceleration device 1 has a tubular superconducting acceleration cavity 10 extending in the axial direction, and a pressure vessel 2 that houses the superconducting acceleration cavity. Although not shown, the superconducting acceleration device 1 is further provided with an emission section that emits the charged particles along the beam axis J, and a refrigerant supply section that supplies a refrigerant R to the inside of the pressure vessel 2. The superconducting acceleration device 1 is also disposed in a housing (not shown) whose inside can be made vacuum.

[0013] The pressure vessel 2 is in the shape of a substantially rectangular parallelepiped box. The pressure vessel 2 has a pair of side walls 2a perpendicular to the beam axis J. The pair of side walls 2a face each other in the axial direction. The pair of side walls 2a support both ends of the superconducting acceleration cavity tube 10, respectively. The inside of the pressure vessel 2 and around the superconducting acceleration cavity tube 10 is filled with a refrigerant R. The refrigerant R is, for example, liquid helium, liquid hydrogen, gaseous helium, or gaseous hydrogen. The pressure vessel 2 has sufficient strength to be able to withstand the pressure of the refrigerant R.

[0014] <Superconducting acceleration cavity tube> 2 is a perspective view of the superconducting acceleration cavity tube 10 of this embodiment. The superconducting acceleration cavity tube 10 has a tube main body 10A and a pair of flange portions 18, 19. The tube main body 10A has an axially symmetric shape centered on the beam axis J. The tube main body 10A has a first pipe portion 11, a second pipe portion 12, and a multiple cell portion 20. The internal spaces of the first pipe portion 11, the second pipe portion 12, and the multiple cell portion 20 are communicated along the beam axis J.

[0015] The first pipe section 11 and the second pipe section 12 constitute both ends of the superconducting acceleration cavity tube 10. The first pipe section 11 is connected to one end of the multiple cell section 20, and the second pipe section 12 is connected to the other end of the multiple cell section 20.

[0016] As shown in FIG. 1, the first pipe section 11 and the second pipe section 12 are supported by a side wall section 2a of a pressure vessel 2. A flange section 18 is provided at the end of the first pipe section 11 opposite the multiple cell section 20. A port tube (not shown) is also provided on the first pipe section 11. Similarly, a flange section 19 is provided at the end of the second pipe section 12 opposite the multiple cell section 20. A port tube (not shown) is also provided on the second pipe section 12. The port tubes of the first pipe section 11 and the second pipe section 12 are, for example, beam tubes.

[0017] The multiple cell section 20 extends in the axial direction centered on the beam axis J. The multiple cell section 20 has a plurality of bulging portions 21 and a plurality of narrowing portions 22. That is, the tube main body 10A has a plurality of bulging portions 21 and a plurality of narrowing portions. The multiple cell section 20 of the present embodiment is provided with four bulging portions 21 and three narrowing portions 22, but the numbers of the bulging portions 21 and narrowing portions 22 are not limited to those of the present embodiment.

[0018] The multiple bulges 21 are arranged in the axial direction. The constricted portions 22 are arranged between the bulges 21 in the axial direction. Therefore, the bulges 21 and the constricted portions 22 are arranged alternately in the axial direction. The bulges 21 and the constricted portions 22 are integrally formed. The bulges 21 have a shape that bulges outward in the radial direction of the beam axis J with respect to the constricted portions 22. On the other hand, the constricted portions 22 have a shape that is constricted inward in the radial direction with respect to the bulges 21. Therefore, the constricted portions 22 have a smaller diameter about the beam axis J than the bulges 21. The outer surface of the bulges 21 is a curved surface that is convex toward the outside, while the outer surface of the constricted portions 22 is a curved surface that is concave when viewed from the outside. The bulges 21 and the constricted portions 22 are smoothly connected with a continuously changing radius of curvature.

[0019] FIG. 3 is a partial cross-sectional view of a tube main body 10A of the present embodiment. As shown in FIG. 3, the tube main body 10A has a reinforcing layer 31, a base layer 32, and a superconducting layer 33. The reinforcing layer 31, the base layer 32, and the superconducting layer 33 are stacked in this order from the radially outer side toward the radially inner side. The reinforcing layer 31, the base layer 32, and the superconducting layer 33 are each formed to have a substantially uniform thickness over the entire length of the tube main body 10A. The thickness of the reinforcing layer 31 is greater than the thicknesses of the base layer 32 and the superconducting layer 33. In addition, the superconducting layer 33 is a thin film, and the thickness of the superconducting layer 33 is sufficiently smaller than the thicknesses of the reinforcing layer 31 and the base layer 32.

[0020] By making the thickness of the reinforcing layer 31 approximately uniform within an appropriate range, it is possible to ensure sufficient strength of the tube main body 10A while preventing the reinforcing layer 31 from interfering with the cooling of the superconducting layer 33 by the refrigerant R. By making the thickness of the base material layer 32 approximately uniform within an appropriate range, it is possible to reduce the amount of material used that constitutes the base material layer 32 while sufficiently suppressing electrical resistance even when a defect occurs in the superconducting layer 33 and current flows bypassing the base material layer 32. By making the thickness of the superconducting layer 33 approximately uniform within an appropriate range, it is possible to fully exhibit the superconducting characteristics.

[0021] The reinforcing layer 31 has an outer surface 31a facing radially outward and an inner surface 31b facing radially inward. The outer surface 31a of the reinforcing layer 31 contacts the refrigerant R. The inner surface 31b of the reinforcing layer 31 is joined to the base layer 32. The reinforcing layer 31 is made of stainless steel. The stainless steel used for the reinforcing layer 31 is preferably austenitic stainless steel, which is a non-magnetic material. By making the reinforcing layer 31 out of a non-magnetic material, it is possible to suppress the influence of the magnetism of the reinforcing layer 31 on the magnetic field inside the superconducting acceleration cavity tube 10, and it is possible to efficiently accelerate the charged particles.

[0022] The substrate layer 32 has an outer surface 32a facing radially outward and an inner surface 32b facing radially inward. The outer surface 32a of the substrate layer 32 is joined to the reinforcing layer 31. A superconducting layer 33 is formed on the inner surface 32b of the substrate layer 32. The substrate layer 32 is made of copper or a copper alloy. The substrate layer 32 is selected from those containing copper as a main component and capable of making the superconducting layer 33 dense. When the substrate layer 32 is made of a copper alloy, the metal material contained in the copper alloy is not particularly limited.

[0023] The superconducting layer 33 is made of magnesium boride (MgB2). Magnesium boride is a hexagonal layered material, and exhibits stable superconducting properties when cooled to about 20 K to about 30 K. The superconducting layer 33 is cooled by a refrigerant R via the reinforcing layer 31 and the base layer 32. The superconducting layer 33 is formed by a method of depositing magnesium boride on the inner surface 32b of the base layer 32 in a vacuum atmosphere, such as a vacuum deposition method or a sputtering method.

[0024] As shown in FIG. 1, a plurality of acceleration electric field generating regions A are provided inside the superconducting acceleration cavity tube 10. The plurality of acceleration electric field generating regions A are arranged side by side on the beam axis J. The acceleration electric field generating regions A are located radially inside the bulges 21 in the axial direction. Since the superconducting acceleration cavity tube 10 of this embodiment has four bulges 21, four acceleration electric field generating regions A are provided inside the superconducting acceleration cavity tube 10. By passing a high-frequency current through the superconducting layer 33, an electric field that accelerates charged particles located on the beam axis J is generated in the acceleration electric field generating region A.

[0025] <Manufacturing method of superconducting acceleration cavity tube> Next, a method for manufacturing the superconducting accelerating cavity tube 10 of this embodiment will be described. 4 is a flow chart showing a method for manufacturing the superconducting acceleration cavity tube 10 of this embodiment. The manufacturing method for the superconducting acceleration cavity tube 10 includes a cladding material forming step S10, a tube forming step S20, and a film forming step.

[0026] 5 is a schematic diagram of a clad material 40 formed in the clad material forming step S10. The clad material 40 of this embodiment is plate-shaped. The clad material 40 has a reinforcing layer 31 made of stainless steel and a base layer 32 made of copper or a copper alloy. The clad material 40 is formed by bonding the stainless steel, which is the material constituting the reinforcing layer 31, and the copper or copper alloy, which is the material constituting the base layer 32, under pressure while heating. As a more specific bonding method, for example, a conventionally known method such as an explosive bonding method, a rolling method, or a diffusion bonding method can be used.

[0027] 6 is a schematic diagram showing the pipe forming step S20. The pipe forming step S20 is a step of forming the clad material 40 into a pipe shape with the base material layer 32 on the inside. The pipe forming step S20 includes a plastic deformation step S21, a joining step S22, a heat treatment step S23, and a polishing step S24.

[0028] The plastic deformation step S21 is a step of plastically deforming the clad material 40 to form a plurality of concave members 41 and a pair of pipe-shaped members 42. The concave members 41 are formed in a substantially hemispherical shape with the base layer 32 facing inward. The concave members 41 open on both sides in the axial direction. The concave members 41 have a first opening 41a and a second opening 41b facing the opposite side of the first opening 41a in the axial direction. The first opening 41a has a larger diameter than the second opening 41b. In the plastic deformation step S21 of this embodiment, eight concave members 41 are formed. The concave members 41 are formed, for example, by pressing. The concave members 41 may also be formed by drawing. The pair of pipe-shaped members 42 are formed, for example, by plastically deforming the clad material 40 into a cylindrical shape with the base layer 32 facing inward and joining the ends of the pipe-shaped members 42 by joining means such as welding.

[0029] The joining step S22 is a step of joining the multiple concave members 41 and the pair of pipe-shaped members 42 by joining means such as welding. The multiple concave members 41 are arranged with the first openings 41a and the second openings 41b alternately inverted, and the mutually facing first openings 41a and the mutually facing second openings 41b are joined together. This forms a multiple cell section 20 (see FIG. 1) having four bulges 21. Furthermore, the pipe-shaped members 42 are joined to the pair of second openings 41b at both ends of the multiple cell section 20 to form the outer shape of the tube main body 10A.

[0030] The heat treatment step S23 is a step of performing heat treatment on the pipe body 10A formed through the plastic deformation step S21 and the joining step S22. Austenitic stainless steel is used as the stainless steel constituting the reinforcing layer 31 of the clad material 40. However, there is a concern that the crystal structure of the stainless steel may change due to the pressurization and heating for forming the clad material 40 and the plastic processing for forming the pipe body 10A, causing the reinforcing layer 31 to lose its non-magnetic properties. In the heat treatment step S23, the reinforcing layer 31 of the pipe body 10A is subjected to heat treatment to adjust the metal structure, thereby making the reinforcing layer 31 an austenitic stainless steel. The time and temperature of the heat treatment are determined by a conventionally known method for making the reinforcing layer 31 have an austenitic crystal structure.

[0031] The polishing step S24 is a step of polishing the inner surface 32b of the base layer 32. By performing the polishing step S24, the surface properties of the inner surface 32b of the base layer 32 can be adjusted, and the formation of the superconducting layer 33 on the inner surface 32b can be stabilized. As the polishing method in the polishing step S24, a conventionally known method can be adopted.

[0032] The pipe forming step S20 that can be adopted in this embodiment has been described above. The pipe forming step S20 of this embodiment described here is one example, and the pipe forming step S20 may be a step of forming the outer shape of the pipe main body 10A through other procedures. For example, the pipe forming step S20 may be a step of forming the outer shape of the pipe main body 10A by performing a necking process on a cylindrical clad material having a reinforcing layer 31 and a base material layer 32, and then performing hydraulic forming in which hydraulic pressure is applied to the inside. In this case, the pipe main body 10A can be a seamless pipe that does not have a welded portion.

[0033] FIG. 7 is a schematic diagram showing the film forming step S30. The film forming step S30 is a step of depositing a superconducting layer 33 on the inner surface 32b of the base layer 32 under a vacuum atmosphere. The film forming step S30 in this embodiment is performed by magnetron sputtering. In this embodiment, the film forming step S30 is performed using a film forming apparatus 50. The film forming apparatus 50 has a shaft portion 52 extending in the axial direction along the beam axis J, and a sputtering target 51 attached to the tip of the shaft portion 52. The shaft portion 52 is movable in the axial direction. The shaft portion 52 is also rotatable about the beam axis J. The sputtering target 51 is made of magnesium boride. The magnesium boride constituting the sputtering target 51 is sputtered outward in the radial direction by a magnetic field formed at the tip of the shaft portion 52, and is deposited on the inner surface 32b of the base layer 32. The film forming apparatus 50 can disperse the scattering direction of the sputtering particles 51a in the circumferential direction by rotating the shaft portion 52. The film forming apparatus 50 can form the superconducting layer 33 over the entire length of the inner surface 32b by moving in the axial direction. Note that in this embodiment, the film forming process performed by the sputtering method has been described. However, the film forming process may be performed by other methods such as a vacuum deposition method or an atomic layer deposition (ALD) film forming method.

[0034] <Summary> The superconducting acceleration cavity tube 10 of this embodiment is a superconducting acceleration cavity tube that accelerates charged particles along the beam axis J, and includes a tube main body 10A extending in the axial direction of the beam axis J. The tube main body 10A has a reinforcing layer 31 made of stainless steel, a base layer 32 bonded to the inner surface 31b of the reinforcing layer 31, and a superconducting layer 33 formed on the inner surface 32b of the base layer 32. With this configuration, the base layer 32 can be reinforced by the reinforcing layer 31 made of stainless steel. In general, stainless steel has a higher strength than the material constituting the base layer 32, that is, copper or copper alloy in this embodiment. By reinforcing the base layer 32 with the reinforcing layer 31, the tube main body 10A can be made significantly thinner than a tube main body having a thick base layer 32 without the reinforcing layer 31 to achieve the same strength. This allows the amount of material used for the base layer 32 used in the tube main body 10A to be reduced, and the manufacturing cost of the superconducting acceleration cavity tube 10 can be reduced. In addition, by thinning the tube main body 10A, the heat capacity of the tube main body 10A can be reduced, and the superconducting layer 33 can be efficiently cooled by the refrigerant R filled on the radial outside of the reinforcing layer 31 through the reinforcing layer 31 and the base layer 32. As a result, the amount of refrigerant R used to cool the superconducting layer 33 can be reduced, and the operating cost of the superconducting acceleration cavity tube 10 can be reduced. In addition, stainless steel is generally widely used as a reinforcing member in the industrial field, and by using stainless steel as the reinforcing layer 31, conventional knowledge for constructing a reinforcing structure can be used in the design of the superconducting acceleration cavity tube 10. Therefore, according to this embodiment, the strength design against pressure of the superconducting acceleration cavity tube 10 becomes easy.

[0035] In the superconducting acceleration cavity tube 10 of this embodiment, the base layer 32 is made of copper or a copper alloy, and the superconducting layer 33 is made of magnesium boride. The superconducting layer 33 made of magnesium boride is easily formed into a dense crystal structure by being formed on the surface of copper or a copper alloy. Therefore, according to the above-mentioned configuration, a dense superconducting layer 33 can be formed on the inner surface 32b of the base layer 32. In addition, it is known that magnesium boride exhibits superconducting properties at high temperatures compared to other superconducting materials. By adopting magnesium boride as a material constituting the superconducting layer 33, the amount of refrigerant R used to cool the superconducting layer 33 can be reduced compared to the case of adopting other superconducting materials, and the operating cost of the superconducting acceleration cavity tube 10 can be reduced.

[0036] In the superconducting acceleration cavity tube 10 of this embodiment, the tube main body 10A has a plurality of bulging portions 21 arranged in the axial direction, and a plurality of constricted portions 22 located between the bulging portions 21 in the axial direction and having a smaller diameter than the bulging portions 21. With this configuration, charged particles can be efficiently accelerated in the acceleration electric field generation region A. Furthermore, even in the case of adopting a multiple cell structure having the bulging portions 21 and the constricted portions 22 as in this embodiment, the base layer 32 can be sufficiently reinforced against the pressure of the refrigerant R by reinforcing the base layer 32 with the reinforcing layer 31.

[0037] The superconducting accelerator 1 of the present embodiment includes a superconducting acceleration cavity tube 10, and a pressure vessel 2 that houses the superconducting acceleration cavity tube 10 and is filled with a refrigerant R that contacts the outer surface 31a of the reinforcing layer 31. With this configuration, the superconducting accelerator 1 can be manufactured and operated at low cost.

[0038] The manufacturing method of the superconducting accelerating cavity tube 10 of the present embodiment is a manufacturing method of the superconducting accelerating cavity tube 10 having a tube main body 10A extending in the axial direction of the beam axis J, the tube main body 10A having a reinforcing layer 31 made of stainless steel, a base layer 32 bonded to an inner surface 31b of the reinforcing layer 31, and a superconducting layer 33 formed on the inner surface 32b of the base layer 32. The manufacturing method of the superconducting accelerating cavity tube 10 includes a clad material forming step S10 and a tube forming step S20. The clad material forming step S10 is a step of bonding the stainless steel and a material constituting the base layer 32 by applying pressure while heating to form a clad material 40 of the reinforcing layer 31 and the base layer. The tube forming step S20 is a step of forming the clad material 40 into a tube shape with the base layer 32 on the inside. According to this configuration, since the tube main body 10A is formed using the clad material 40 in the tube forming step S20, the tube main body 10A can be manufactured in which the reinforcing layer 31 and the base layer 32 are bonded to each other in close contact. This allows the base layer 32 to be fully reinforced in its entirety by the reinforcing layer 31. In addition, by forming the tube main body 10A using the clad material 40, it is easy to make the thickness of each part of the tube main body 10A uniform over its entire length. According to this configuration, it is possible to manufacture a superconducting accelerating cavity tube 10 in which the superconducting layer 33 can be uniformly cooled by the refrigerant R, compared to a case in which the thickness is locally biased.

[0039] The manufacturing method of the superconducting accelerating cavity tube 10 of this embodiment further includes a film-forming step S30 that is performed after the tube-forming step S20. The film-forming step S30 is a step of depositing a superconducting layer 33 on the inner surface 32b of the base layer 32 in a vacuum atmosphere. According to this configuration, by forming the outer shape of the tube main body 10A in the tube-forming step S20 and then forming the superconducting layer 33 in the film-forming step S30, the superconducting layer 33 having a dense crystal structure can be formed along the inner surface 32b of the base layer 32.

[0040] In the manufacturing method of the superconducting accelerating cavity tube 10 of the present embodiment, the base layer 32 is made of copper or a copper alloy, and the superconducting layer 33 is made of magnesium boride. With this configuration, a dense superconducting layer 33 can be formed on the inner surface 32b of the base layer 32.

[0041] In the manufacturing method of the superconducting acceleration cavity tube 10 of the present embodiment, the tube main body 10A has a plurality of bulging parts 21 arranged in the axial direction, and a plurality of constricted parts 22 located between the bulging parts 21 in the axial direction and having a smaller diameter than the bulging parts 21. According to this configuration, even when a multiple cell structure having the bulging parts 21 and the constricted parts 22 is adopted, the superconducting acceleration cavity tube 10 in which the base layer 32 is reinforced with the reinforcing layer 31 can be manufactured.

[0042] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the configurations of the above-mentioned embodiments, and the following configurations and methods may also be adopted. Furthermore, the configurations and methods described in this specification may be appropriately combined within a range that does not contradict each other. For example, the tube body 10A constituting the superconducting acceleration cavity tube 10 may have other layers in addition to the reinforcing layer 31, the base material layer 32, and the superconducting layer 33. Furthermore, the superconducting acceleration cavity tube 10 is not limited to a multi-cell structure having a bulge portion 21 and a constriction portion 22, and may be another type of superconducting acceleration cavity tube called a spoke type or an HWR type.

[0043] Various aspects of the present disclosure are summarized below as appendices.

[0044] (Appendix 1) A superconducting acceleration cavity tube that accelerates charged particles along a beam axis, A tube body extending in an axial direction of the beam axis, The tube body includes: A reinforcing layer made of stainless steel; A base layer bonded to an inner surface of the reinforcing layer; A superconducting layer formed on the inner surface of the base layer. Superconducting acceleration cavity tube. (Appendix 2) The substrate layer is made of copper or a copper alloy, The superconducting layer is made of magnesium boride. Attachment 1 describes a superconducting accelerating cavity tube. (Appendix 3) The pipe main body has a plurality of bulging portions arranged in the axial direction, and a plurality of constricted portions located between the bulging portions in the axial direction and having a smaller diameter than the bulging portions. 3. The superconducting accelerating cavity tube according to claim 1 or 2. (Appendix 4) A superconducting acceleration cavity tube according to any one of appendix 1 to 3; a pressure vessel for housing the superconducting acceleration cavity tube and for filling a refrigerant therein that is in contact with an outer surface of the reinforcing layer; Superconducting accelerator. (Appendix 5) A method for manufacturing a superconducting acceleration cavity tube having a tube body extending in an axial direction of a beam axis, comprising the steps of: The tube body includes: A reinforcing layer made of stainless steel; A base layer bonded to an inner surface of the reinforcing layer; a superconducting layer formed on an inner surface of the base layer; a clad material forming step of bonding the stainless steel and the material constituting the base layer by heating and pressurizing them to form a clad material of the reinforcing layer and the base layer; and a tube forming step of forming the clad material into a tube shape with the base material layer on the inside. A manufacturing method for a superconducting acceleration cavity tube. (Appendix 6) The method further includes a film forming step performed after the tube forming step, The film forming step is a step of depositing the superconducting layer on the inner surface of the base layer in a vacuum atmosphere. A method for manufacturing the superconducting accelerating cavity tube described in Appendix 5. (Appendix 7) The substrate layer is made of copper or a copper alloy, The superconducting layer is made of magnesium boride. 7. A method for manufacturing a superconducting accelerating cavity tube according to claim 5 or 6. (Appendix 8) The pipe main body has a plurality of bulging portions arranged in the axial direction, and a plurality of constricted portions located between the bulging portions in the axial direction and having a smaller diameter than the bulging portions. 8. A method for producing the superconducting accelerating cavity tube according to any one of claims 5 to 7. [Explanation of symbols]

[0045] Reference Signs List 1...superconducting accelerator, 2...pressure vessel, 10...superconducting acceleration cavity tube, 10A...tube body, 21...bulge, 22...neck, 31...reinforcing layer, 31a, 32a...outer surface, 31b, 32b...inner surface, 32...base material layer, 33...superconducting layer, 40...cladding material, J...beam axis, R...refrigerant, S10...cladding material forming process, S20...tube forming process, S30...film forming process

Claims

1. A superconducting acceleration cavity tube that accelerates charged particles along a beam axis, A tube body extending in an axial direction of the beam axis, The tube body includes: A reinforcing layer made of stainless steel; A base layer bonded to an inner surface of the reinforcing layer; A superconducting layer formed on the inner surface of the base layer. Superconducting acceleration cavity tube.

2. The substrate layer is made of copper or a copper alloy, The superconducting layer is made of magnesium boride. The superconducting accelerating cavity tube according to claim 1 .

3. The pipe main body has a plurality of bulging portions arranged in the axial direction, and a plurality of constricted portions located between the bulging portions in the axial direction and having a smaller diameter than the bulging portions. The superconducting accelerating cavity tube according to claim 1 .

4. A superconducting acceleration cavity tube according to any one of claims 1 to 3; a pressure vessel for housing the superconducting acceleration cavity tube and for filling a refrigerant therein that is in contact with an outer surface of the reinforcing layer; Superconducting accelerator.

5. A method for manufacturing a superconducting acceleration cavity tube having a tube body extending in an axial direction of a beam axis, comprising the steps of: The tube body includes: A reinforcing layer made of stainless steel; A base layer bonded to an inner surface of the reinforcing layer; a superconducting layer formed on an inner surface of the base layer; a clad material forming step of bonding the stainless steel and the material constituting the base layer by heating and pressurizing them to form a clad material of the reinforcing layer and the base layer; and a tube forming step of forming the clad material into a tube shape with the base material layer on the inside. A manufacturing method for a superconducting acceleration cavity tube.

6. The method further includes a film forming step performed after the tube forming step, The film forming step is a step of depositing the superconducting layer on the inner surface of the base layer in a vacuum atmosphere. The method for manufacturing the superconducting acceleration cavity tube according to claim 5.

7. The substrate layer is made of copper or a copper alloy, The superconducting layer is made of magnesium boride. The method for manufacturing the superconducting acceleration cavity tube according to claim 5.

8. The pipe main body has a plurality of bulging portions arranged in the axial direction, and a plurality of constricted portions located between the bulging portions in the axial direction and having a smaller diameter than the bulging portions. A method for manufacturing the superconducting acceleration cavity tube according to any one of claims 5 to 7.

Images