Charged particle beam deflection device

Abstract

To provide a charged particle beam deflector capable of smoothly flowing a cooling solvent for cooling a coil.SOLUTION: A charged particle beam deflector comprises: a laminated structure having a hollow shape through which a charged particle beam passes and having a plurality of layers laminated in a direction from the inside to the outside; a first coil for deflecting the charged particle beam in a first direction different from a traveling direction of the charged particle beam; a second coil for deflecting the charged particle beam in a second direction different from the first direction; and a pressing part located on an outer peripheral surface of the laminated structure and pressing the outer peripheral surface from the outside toward the inside. The plurality of layers include a first coil support layer for supporting the first coil, and a second coil support layer for supporting the second coil, where the laminated structure includes a gap allowing a cooling solvent to flow between two adjacent layers out of the plurality of layers.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a charged particle beam deflection device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, particle beam therapy has been performed in which a patient's affected area, such as a cancer, is irradiated with a charged particle beam accelerated to high energy.

[0003] Patent Document 1 describes a technology in which a charged particle beam generated by a beam generator is accelerated by a beam accelerator, the trajectory of the charged particle beam is adjusted by a beam scanner, and the charged particle beam is irradiated onto an affected area of ​​a patient. The beam scanner described in Patent Document 1 has multiple coils that deflect the charged particle beam and a structural member that is configured by stacking multiple layers that support the multiple coils. Patent Document 1 also describes flowing a cooling solvent into gaps in the structural member to cool the coils. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-32611 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the inventors have come to recognize the following problem. Structural members must be constructed by stacking multiple layers with high precision. However, with the technology described in Patent Document 1, when a cooling medium is poured into the gaps between the structural members, the layers that make up the structural members may shift, making it difficult to ensure the water channels as designed. The technology described in Patent Document 1 does not take layer shifting into consideration, and when a cooling medium is poured, the layers may shift, preventing the cooling medium from flowing smoothly enough. As a result, more heat than expected is generated in the coil, making it difficult to achieve the desired therapeutic irradiation.

[0006] The present invention has been made in view of the above circumstances, and one of its exemplary objects is to provide a charged particle beam deflection device that allows a cooling medium for cooling a coil to flow smoothly. [Means for solving the problem]

[0007] To solve the above problems, one aspect of the present invention provides a charged particle beam deflection device, comprising: a laminated structure having a hollow shape through which a charged particle beam passes and including multiple layers stacked in a direction from the inside to the outside; a first coil for deflecting the charged particle beam in a first direction different from the traveling direction of the charged particle beam; a second coil for deflecting the charged particle beam in a second direction different from the first direction; and a pressing unit located on the outer circumferential surface of the laminated structure for pressing the outer circumferential surface from the outside to the inside. The multiple layers include a first coil support layer for supporting the first coil and a second coil support layer for supporting the second coil, and the laminated structure has a gap between two adjacent layers of the multiple layers through which a cooling solvent can flow.

[0008] Any combination of the above components and conversion of the present invention into a method, device, system, etc. are also valid aspects of the present invention. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a charged particle beam deflection device that allows a cooling medium for cooling the coil to flow smoothly. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a charged particle beam irradiation device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the charged particle beam deflection device according to the embodiment. [Figure 3] FIG. 2 is a cross-sectional view of the charged particle beam deflection device according to the embodiment. [Figure 4] FIG. 4 is an enlarged view of an area A shown in FIG. [Figure 5] 5 is a diagram showing an example in which holes having a different shape from the example shown in FIG. 4 are formed in the inflow member. [Figure 6] FIG. 4 is an enlarged view of an area B shown in FIG. [Figure 7] FIG. 1 is a cross-sectional view of the structure perpendicular to the X-axis direction. [Figure 8] FIG. 2 is a perspective view of an inner cylinder according to an embodiment of the present invention. [Figure 9] FIG. 2 is a perspective view of a first reel layer disposed on an inner cylinder. [Figure 10] FIG. 3 is a perspective view showing a waterway member of a first waterway layer according to one embodiment of the present invention. [Figure 11] FIG. 2 is a perspective view of a second reel layer according to the embodiment. [Figure 12] FIG. 2 is a perspective view of an outer cylinder according to the same embodiment. [Figure 13] FIG. 2 is an enlarged view showing a part of a cross section perpendicular to the X-axis of the inner cylinder and the structure. [Figure 14] 10 is an enlarged view showing a part of a cross section perpendicular to the X axis of an inner cylinder and a structure according to a first modified example. FIG. [Figure 15] 10 is an enlarged view showing a part of a cross section perpendicular to the X-axis of an inner cylinder and a structure according to a second modified example. FIG. [Figure 16] FIG. 10 is a schematic diagram illustrating the configuration of a charged particle beam deflector according to a second embodiment. [Figure 17] FIG. 1 is a view of the aligned structure from the exit side of the charged particle beam. [Figure 18] FIG. 10 is an enlarged view showing the structure being aligned by the alignment pins. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated explanations will be omitted as appropriate. Furthermore, the configurations described below are examples and do not limit the scope of the present invention in any way.

[0012] [background] The scanning magnet, which is an electromagnet that scans a charged particle beam, ultimately controls the position of the charged particle beam irradiated onto the human body. Therefore, high precision is required for the installation position of the scanning magnet. If this requirement is not met, deviations will occur in the position where the charged particle beam is irradiated, reducing the accuracy of the treatment. In practice, in treatment sites using scanning magnets, if deviations occur in the position where the charged particle beam is irradiated, the deviation is corrected by an irradiation control system, improving the accuracy of the treatment. Therefore, deviations in the irradiation position are eventually eliminated, but the workload required for this correction is significant. Installing the scanning magnet in the appropriate position to reduce this workload is a major challenge.

[0013] Furthermore, from the perspective of facility management, treatment facility operators are particularly concerned about the return on investment of treatment equipment. After introducing a treatment device, it is necessary to get it up and running as quickly as possible to maximize return on investment. However, simply installing a treatment device does not mean that it can be used for treatment. The treatment device must be adjusted in terms of hardware and software to produce a charged particle beam with sufficient precision for treatment. In this case, accurately installing the physical components of the treatment device shortens the time required for this adjustment, which naturally leads to an increase in the number of patients who can receive treatment.

[0014] In one embodiment of the present invention described below, two pairs of scanning electromagnets are arranged in parallel and the diameters of the scanning electromagnets are inclined, thereby achieving a compact charged particle beam deflection device. A compact charged particle beam deflection device directly translates into easier handling. A compact charged particle beam deflection device improves the operability of adjusting the irradiation of the charged particle beam. The compactness of the device has a significant impact on operability, particularly when installing (introducing) the device.

[0015] However, generally, reducing the diameter reduces the number of coil turns, resulting in a weaker magnetic field generated by the scanning magnet. Similarly, as mentioned above, reducing the axial length also weakens the magnetic field generated by the scanning magnet. A weaker magnetic field weakens the force bending the charged particle beam. When this force weakens, the distance between the scanning magnet and the isocenter must be increased to compensate for the weakened magnetic field and maintain the irradiation field width. When irradiating the charged particle beam from multiple directions by moving the scanning magnet circumferentially around the isocenter, increasing the distance between the scanning magnet and the isocenter increases the size of the device. This is because the distance between the scanning magnet and the isocenter is the radius of the circle in which the scanning magnet moves. As the circle in which the scanning magnet moves becomes larger, the device must be correspondingly larger.

[0016] Therefore, it is conceivable to maintain the size of the device by increasing the current value used in the scanning magnet to generate a magnetic field of sufficient strength to scan the charged particle beam. However, using a large current makes cooling the scanning magnet more important. Therefore, effective cooling of the scanning magnet is a major challenge. Therefore, one embodiment of the present invention provides a charged particle beam deflection device that allows a smooth flow of cooling solvent for cooling the scanning magnet.

[0017] [First embodiment] 1 is a schematic diagram of a charged particle beam irradiation system 1 according to this embodiment. The charged particle beam irradiation system 1 includes an accelerator 10, a charged particle beam transport system 12, a bending electromagnet 14, and an irradiation nozzle 16. The irradiation nozzle 16 is disposed in a treatment room 18 equipped with a treatment table on which a patient is placed.

[0018] The accelerator 10 is a device that generates a charged particle beam, and may be, for example, a synchrotron, a cyclotron, or a linear accelerator. The charged particle beam generated by the accelerator 10 is guided to a bending electromagnet 14 through a charged particle beam transport system 12. Here, the charged particle beam may be any of various known charged particle beams, and the charged particles may be, for example, a proton beam, alpha particles, heavy particles, or electrons.

[0019] The charged particle beam transport system 12 includes one or more charged particle beam conditioning means 122, a vacuum duct 124, a deflection electromagnet 126, and a fan-shaped vacuum duct 128. The accelerator 10, the charged particle beam conditioning means 122, and the deflection electromagnet 126 are connected by the vacuum duct 124, and the deflection electromagnet 126 and the bending electromagnet 14 are connected by the fan-shaped vacuum duct 128.

[0020] The charged particle beam is generated in the upstream accelerator 10, travels through the vacuum duct 124 and the fan-shaped vacuum duct 128 to avoid (or reduce) attenuation, and is guided to the downstream bending electromagnet 14 while being adjusted by the charged particle beam adjustment means 122.

[0021] The charged particle beam adjusting means 122 may be provided with a beam slit for adjusting the beam shape and / or dose of the charged particle beam, an electromagnet for adjusting the traveling direction of the charged particle beam, a quadrupole electromagnet for adjusting the beam shape of the charged particle beam, and a steering electromagnet for finely adjusting the beam position of the charged particle beam, etc., as appropriate according to specifications.

[0022] The irradiation nozzle 16 is located in a treatment room 18 where treatment using a charged particle beam is performed, and emits a charged particle beam from the irradiation nozzle 16. Treatment is performed by irradiating the affected area with the charged particle beam emitted from the irradiation nozzle 16. The irradiation nozzle 16 according to this embodiment includes a charged particle beam deflector that adjusts the amount and direction of the current flow to fine-tune the direction of travel of the charged particle beam emitted from the irradiation nozzle 100, enabling scanning within a predetermined range. This allows the irradiation nozzle 16 to scan the charged particle beam two-dimensionally.

[0023] Fig. 2 is a perspective view of the charged particle beam deflection device 20 according to this embodiment. Fig. 3 is a cross-sectional view of the charged particle beam deflection device 20 according to this embodiment. The charged particle beam deflection device 20 according to this embodiment includes an outflow member 22, an inflow member 24, a yoke 26, an inner cylinder 30, an outer cylinder 32, and a structure 40.

[0024] The inner cylinder 30 has a hollow shape and is configured so that a charged particle beam passes through its interior. An entrance port 230 is provided at one end of the inner cylinder 30, and an exit port 250 is provided at the other end. The charged particle beam enters through the entrance port 230, passes through the internal space 300 of the inner cylinder 30, and exits through the exit port 250. The inner cylinder 30 is configured so that its inner and outer diameters increase nonlinearly or linearly from the entrance side to the exit side.

[0025] Here, the X-axis shown in FIG. 3 is an axis passing through the central axis of the inner cylinder 30, and its direction is from the entrance 230 to the exit 250. Furthermore, hereinafter, the "entrance side" refers to the entrance 230 side on the X-axis, and the "exit side" refers to the exit 250 side on the X-axis. Furthermore, the Y-axis shown in FIG. 3 is a direction perpendicular to the X-axis and is the radial direction of the inner cylinder 30. Note that in this specification, the Y-axis direction may refer to the direction from the inside to the outside, and the opposite direction may refer to the direction from the outside to the inside.

[0026] The structure 40 is fixed to the inner cylinder 30 so as to cover the outer peripheral surface of the inner cylinder 30. In other words, the inner cylinder 30 is fixed to the structure 40 so that its outer peripheral surface covers the inner peripheral surface of the structure 40. The structure 40 includes a laminated structure and a coil, which will be described later. The coil is configured to function as a scanning electromagnet that deflects the charged particle beam passing through the internal space 300 of the inner cylinder 30. The structure 40 is configured so that its inner and outer diameters increase linearly or nonlinearly from the entrance side to the exit side.

[0027] The outer cylinder 32 is fixed to the structure 40 so as to cover the outer peripheral surface of the structure 40. The yoke 26 is connected to the inflow member 24 by a fixing member 249 so as to be located on the outer peripheral surface of the structure 40. In this embodiment, the yoke 26 is not provided over the entire length of the structure 40. More specifically, the yoke 26 is located in the central region of the outer peripheral surface of the structure 40, and is arranged so as not to be located at the end on the incident side or the end on the output side of the outer peripheral surface of the structure 40.

[0028] The outflow member 22 is fixed to the inner tube 30 and the outer tube 32 and forms part of a path through which a cooling medium passes to cool the coil provided in the structure 40. The inflow member 24 is fixed to the inner tube 30 and the outer tube 32 and forms part of a path through which a cooling medium passes. The outflow member 22 and the inflow member 24 may be made of an insulating material such as FRP (fiber reinforced plastics). In this embodiment, a current introduction terminal (not shown) for passing current through the coil is disposed near the inflow member 24. By making the inflow member 24 out of an insulating material, the inflow member 24 can be insulated from the structure 40 and the current introduction terminal. The outflow member 22 and the inflow member 24 may be made of a combination of multiple members and a non-magnetic material such as stainless steel. This facilitates assembly, making screwing and welding, for example, easier.

[0029] The cooling medium may be any known coolable liquid, and in this embodiment, the cooling medium is water. In Fig. 3, the arrows shown on the outflow member 22, the inflow member 24, and the structure 40 indicate the flow direction of the cooling medium. That is, the cooling medium flows in through the inflow member 24, passes through the gaps in the structure 40, and is discharged through the outlet 221 provided in the outflow member 22.

[0030] Fig. 4 is an enlarged view of region A shown in Fig. 3. As shown in Fig. 4, inflow member 24 includes output-side end portion 240 and output-side pressing portion 241. Output-side end portion 240 is disposed so as to cover output-side end face 43 of structure 40, and functions as a covering member. This allows the coil and other components of structure 40 to be protected by output-side end portion 240. Note that the portion of output-side end portion 240 below dashed line 248 can also be considered as the covering member.

[0031] The output-side pressing unit 241 is configured to press the outer cylinder 32 from the outside toward the inside. As a result, the structure 40 is pressed from the outside toward the inside. The structure 40 according to this embodiment has a laminated structure having multiple layers stacked in a direction from the inside toward the outside. Because this laminated structure is pressed by the output-side pressing unit 241 via the outer cylinder 32, the layers constituting the laminated structure are prevented from shifting when the cooling solvent flows through the gaps in the laminated structure.

[0032] Furthermore, in this embodiment, the output-side pressing portion 241 is an annular member that goes around the entire circumference of the structure 40 and is located on the outer circumferential surface of the structure 40. Therefore, the output-side pressing portion 241 can press the entire circumference of the structure 40, and therefore, it is possible to more reliably suppress misalignment of layers in the laminated structure of the structure 40.

[0033] In this embodiment, the output-side pressing portion 241 has a hollow portion 242 in which a hole 244 is formed and an output-side protrusion 243 that protrudes toward the output side beyond the end face 43 of the structure 40. The output-side pressing portion 241 is connected to the output-side end 240 via the output-side protrusion 243. As a result, a space 246 surrounded by the end face 43 of the structure 40, the output-side end 240, and the output-side pressing portion 241 is formed inside the inflow member 24. This space 246 is in communication with the gaps in the laminated structure of the structure 40 and forms part of the flow path for the cooling solvent. Note that the portion of the output-side end 240 above the dashed line 248 can also be considered part of the protrusion that protrudes toward the output side beyond the end face 43 of the structure 40.

[0034] The hollow portion 242 has holes 244 that open in a direction from the end surface 43 of the structure 40 toward the center of the structure 40 and communicate with the space 246. In this embodiment, the holes 244 form part of a flow path for the cooling solvent. The cooling solvent flows in through the holes 244, passes through the space 246, and flows into the gaps in the structure 40.

[0035] In addition, in this embodiment, the emission-side end portion 240 is disposed away from the end face 43 of the structure 40. The inner cylinder 30 functions as a closing portion that closes an opening 247 on the interior side of the structure 40, which is formed between the emission-side end portion 240 and the end face 43 and is included in the space 246. This prevents the cooling solvent from flowing from the space 246 in an unintended direction.

[0036] In this embodiment, the hole 244 is formed in the exit-side pressing portion 241 in a direction parallel to the traveling direction of the charged particle beam. Referring to FIG. 5 , a case where the hole is formed in another form will be described. In the example shown in FIG. 5 , the inflow member 25 has a space 252 therein, and this space 252 communicates with a hole 253 extending from the space 252 in the X-axis direction (the direction from the entrance side to the exit side) and a hole 254 extending from the space 252 in the Y-axis direction. Connection portions 256 and 257 for connecting hoses 258 and 259 are provided at the ends of the hole 253 and the hole 254, respectively. Arrows inside the hoses 258 and 259 indicate the direction in which the cooling solvent flows. While FIG. 5 shows an example in which two holes, hole 253 and hole 254, are formed, it is also possible to form only one of the holes.

[0037] As shown in FIG. 5 , hoses 258, 259, etc., must be connected to holes 253, 254 formed in the inflow member 25 to allow the cooling solvent to flow into the holes 253, 254. At this time, space is required for connection portions 256, 257 for connecting the hoses 258, 259 and the widths of the hoses 258, 259 themselves. For example, a space of width d1 for the connection portion 256 and the hose 258 must be provided in the X-axis direction, and a space of width d2 for the connection portion 257 and the hose 259 must be provided in the Y-axis direction. On the other hand, according to this embodiment, the hole 244 is formed in the exit-side pressing portion 241 in the opposite direction of the X-axis from the hole 253. This prevents the device from becoming larger in the X-axis direction, the Y-axis direction, or the radial direction of the X-axis direction, thereby enabling the charged particle beam deflection device to be made more compact.

[0038] Fig. 6 is an enlarged view of region B shown in Fig. 3. As shown in Fig. 6, outflow member 22 has an incident-side end portion 220 and an incident-side pressing portion 226. Incident-side end portion 220 has an incident-side protrusion 222 that protrudes from incident-side pressing portion 226 in the incident-side direction, and an incident-side covering portion 224 that is arranged to cover incident-side end face 44 of structure 40. Incident-side covering portion 224 functions as a covering member, and the coil and the like of structure 40 are protected by incident-side covering portion 224.

[0039] The entrance-side pressing unit 226 is configured to press the outer cylinder 32 from the outside toward the inside. The structure 40 is pressed from the outside toward the inside by the entrance-side pressing unit 226. Therefore, when the cooling solvent flows through the structure 40, displacement of the layers constituting the laminated structure of the structure 40 is suppressed.

[0040] In this embodiment, the incident-side pressing portion 226 is an annular member that goes around the entire circumference of the structure 40 and is located on the outer circumferential surface of the structure 40. Therefore, the incident-side pressing portion 226 can press the entire circumference of the structure 40, and therefore, it is possible to more reliably suppress misalignment of layers in the laminated structure of the structure 40.

[0041] In this embodiment, the incident-side end 220 is coupled to the incident-side pressing portion 226 via the incident-side protrusion 222. As a result, a space 232 surrounded by the incident-side end 220 and the end face 44 of the structure 40 is formed inside the outflow member 22. This space 232 communicates with the gaps in the laminated structure of the structure 40 and forms part of a flow path for the cooling solvent. The cooling solvent that has flowed from the structure 40 into the space 232 is discharged from the outlet 221 shown in FIG. 2 through a hole (not shown).

[0042] Furthermore, the incident-side covering part 224 is disposed away from the end face 44 of the structure 40, and an opening 233 is formed between the incident-side covering part 224 and the end face 44, which are included in the space 232. In this embodiment, the inner cylinder 30 functions as a closing part that closes the opening 233 on the inside side of the structure 40. This prevents the cooling solvent flowing in the space 232 from flowing in an unintended direction.

[0043] 7 is a cross-sectional view of the structure 40 perpendicular to the X-axis. In FIG. 7, the Z-axis is an axis perpendicular to the X-axis and the Y-axis. The structure 40 according to this embodiment includes a stacked structure 42, a first coil 50 that deflects the charged particle beam in a first direction different from the traveling direction of the charged particle beam, and a second coil 52 that deflects the charged particle beam in a second direction different from the traveling direction of the charged particle beam and the first direction.

[0044] The first coil 50 and the second coil 52 are arranged in pairs facing each other across the internal space 300. Alternatively, each pair of the first coil 50 and the second coil 52 may be arranged in parallel. That is, the first coil 50 and the second coil 52 may be arranged so that a cross section of the structure 40 perpendicular to the X-axis including both coils exists, as shown in FIG. 7. When a current flows through the first coil 50 and the second coil 52, the first coil 50 and the second coil 52 generate a magnetic field, which deflects the charged particle beam.

[0045] The laminated structure 42 has a hollow shape through which the charged particle beam passes, and includes multiple layers stacked from the inside to the outside. Each layer may be made of, for example, various synthetic resins. The laminated structure 42 also has a gap between two adjacent layers through which a cooling solvent can flow. Each of these layers has a hollow shape, and is configured so that the inner and outer diameters increase linearly or nonlinearly from the entrance side to the exit side.

[0046] The laminated structure 42 according to this embodiment includes a plurality of reel layers (coil support layers) on which coils are arranged, and a plurality of water channel layers that are arranged between two adjacent reel layers and form paths for the cooling medium. In this embodiment, the coils arranged on two adjacent reel layers are connected to each other. The first coils 50 arranged on each reel layer are electrically connected to each other, and similarly, the second coils 52 arranged on each reel layer are electrically connected to each other.

[0047] The structure 40 according to this embodiment has nine reel frame layers and nine water channel layers. More specifically, the structure 40 has, from the inside out, a first reel frame layer 400, a first water channel layer 420, a second reel frame layer 440, ..., a ninth reel frame layer 460, and a ninth water channel layer 480. The structure 40 according to this embodiment has nine reel frame layers, but FIG. 7 shows three of these. The number of reel frame layers may be eight or less, or ten or more. The laminated structure 42 according to this embodiment has nine water channel layers, but FIG. 7 shows three of these. The number of water channel layers may be eight or less, or ten or more.

[0048] The first bobbin layer 400 is disposed so as to cover the outer peripheral surface of the inner cylinder 30, and is a coil support layer (first coil support layer) that supports a coil 502 (first coil) that deflects the charged particle beam. The coil 502 according to this embodiment generates a magnetic field in the Z-axis direction, and deflects the charged particle beam by this magnetic field.

[0049] The first water channel layer 420 is disposed so as to cover the outer peripheral surface of the first reel layer 400, and is a layer that forms part of the path through which the cooling solvent passes.

[0050] The second reel layer 440 is a layer in which a coil 504 (first coil) for deflecting the charged particle beam is arranged. Similar to the coil 502, the coil 504 generates a magnetic field in the Z-axis direction, and deflects the charged particle beam using this magnetic field.

[0051] 7, the third to eighth reel layers and the second to eighth water channel layers are laminated alternately on the outer peripheral surface of the second reel layer 440. Each of the third to fifth reel layers is a coil support layer (first coil support layer) that supports a coil (first coil), and each coil is configured to generate a magnetic field in the Z-axis direction, similar to coils 502 and 504.

[0052] The ninth reel layer 460 is arranged to cover the outer surface of the eighth water channel layer (not shown), and is a coil support layer (second coil support layer) that supports the coil 522 (second coil) that deflects the charged particle beam in a direction (second direction) different from the direction (first direction) in which the coils (e.g., coils 502, 504, etc.) arranged on the first to fifth reel frames deflect the charged particle beam.

[0053] A coil 522 is disposed on the ninth bobbin layer 460. The coil 522 generates a magnetic field in the Y-axis direction and deflects the charged particle beam traveling in the X-axis direction in the Z-axis direction. In addition, a coil (second coil) is disposed on each of the sixth to eighth bobbin layers, and each coil is configured to generate a magnetic field in the Y-axis direction, similar to the coil 522.

[0054] The ninth water channel layer 480 is disposed so as to cover the outer peripheral surface of the ninth reel layer 460, and is a layer that forms part of the path through which the cooling solvent passes. The outer cylinder 32 is disposed on the outer peripheral surface of the ninth water channel layer 480. The outer cylinder 32 is disposed so that its inner peripheral surface covers the outer peripheral surface of the ninth water channel layer 480.

[0055] Fig. 8 is a perspective view of the inner cylinder 30 according to this embodiment. As shown in Fig. 8, a groove 302 is formed along the longitudinal direction on the outer peripheral surface of the inner cylinder 30. This groove 302 forms part of a path for the cooling medium.

[0056] 9 is a perspective view of the first reel layer 400 arranged in the inner cylinder 30. Grooves 402 are formed in the first reel layer 400. Litz wire is embedded in this groove 402 and hardened with resin, thereby forming a coil (first coil). The Litz wire is a wire material formed by twisting together multiple thin conductors insulated with an insulating material such as enamel.

[0057] FIG. 10 is a perspective view showing a water channel member 422 of the first water channel layer 420 according to this embodiment. The water channel member 422 shown in FIG. 10 constitutes half of the first water channel layer 420. Another water channel member has a configuration similar to the water channel member 422 shown in FIG. 10 , and by combining these two water channel members, the first water channel layer 420 is formed, which surrounds the outer peripheral surface of the first reel layer 400. The water channel member 422 has grooves 424 on its outer peripheral surface, which form part of a path through which the cooling solvent passes. Note that, like the first water channel layer, each water channel layer included in the laminated structure 42 is formed by combining two water channel members to form a surrounding water channel layer. Note that, in this embodiment, an example in which each water channel layer is formed by a water channel member will be described; however, each water channel layer may be formed simply as a space without using a water channel member.

[0058] FIG. 11 is a perspective view of the second reel layer 440 according to this embodiment. FIG. 11 shows the second reel layer 440 disposed on the surface of the first conduit layer 420. Grooves 444 are formed on the surface of the second reel layer 440, and Litz wires are embedded in these grooves 444 to form the coil 504. The grooves 444 may be formed as holes that penetrate the second reel layer 440 from the front to the back, or may be formed so as not to penetrate the second reel layer 440 from the front to the back. A second conduit layer is disposed on the outer surface of the second reel layer 440 so as to cover the outer surface. Grooves are formed on the inner circumferential surface of the second conduit layer, and these grooves and the outer surface of the second reel layer 440 form part of a path through which the cooling solvent passes. In this way, the reel layer and the water channel layer are laminated on the outer peripheral surface of the inner cylinder 30, and the outer cylinder 32 shown in Figure 12 is arranged on the outer peripheral surface of the outermost water channel layer so as to cover that outer peripheral surface.

[0059] 13 is an enlarged view showing a part of a cross section perpendicular to the X-axis of the inner cylinder 30 and the structure 40. In the charged particle beam deflection device 20 according to this embodiment, a path through which a cooling solvent flows is formed between the groove 302 provided on the outer surface of the inner cylinder 30 and the coil 502 arranged on the first reel layer 400. Therefore, in the charged particle beam deflection device according to this embodiment, the cooling solvent can flow through the gap where the inner cylinder 30 and the coil 502 do not contact each other, compared to when the inner cylinder 30 is in contact with the coil 502, and therefore the coil 502 can be cooled more efficiently by the cooling solvent.

[0060] Furthermore, paths for the cooling solvent to flow are formed between groove 423 formed on the inner surface of first water channel layer 420 and coil 502, and between groove 424 formed on the outer surface of first water channel layer 420 and coil 504 disposed on second reel layer 440. Furthermore, paths for the cooling solvent to flow are formed between groove 454 formed on the inner surface of second water channel layer 450 and coil 504. Similarly, the grooves formed on the outer surface of second water channel layer 450 and the grooves formed on the surface of each water channel layer form paths for the cooling solvent to flow between adjacent reel layers or coils.

[0061] As described above, in the charged particle beam deflection device according to this embodiment, a large current flows through the coil. Therefore, it is necessary to more reliably cool the coil with a cooling solvent. If the cooling solvent flows through the gaps between the layers of the laminated structure, the layers may become misaligned. If the layers become misaligned, the flow of the cooling solvent may be impeded, and smooth cooling may not be achieved. If smooth cooling is not achieved, the coil may become extremely hot due to the large current.

[0062] In this embodiment, the entrance-side pressing portion 226 and the exit-side pressing portion 241 press the laminated structure 42 from the outside toward the inside. Therefore, each layer of the laminated structure 42 is pressed by these pressing portions, and thus the positional deviation of each layer is suppressed. As a result, the cooling solvent can flow smoothly through the gaps in the laminated structure 42, and the coil can be cooled smoothly.

[0063] In this embodiment, the outflow member 22, the inflow member 24, the inner tube 30, and the structure 40 form spaces 232 and 246 that communicate with the gaps in the structure 40, and these spaces are used as water channels through which the cooling solvent flows. This allows for a water channel with a simple structure, allowing the cooling solvent to flow smoothly. Furthermore, these spaces can be used to collectively fix litz wires, etc., that connect the layers of the reel. In this case, the litz wires can be collectively cooled.

[0064] Furthermore, according to this embodiment, it is possible to suppress misalignment of the layers in the laminated structure 42, thereby suppressing misalignment of the coils arranged on the bobbin layer, thereby enabling the coils to generate a magnetic field as designed with higher precision.

[0065] [First Modification] 14 is an enlarged view showing a part of a cross section perpendicular to the X-axis of the inner cylinder 30 and the structure 40 according to the first modified example. In the example shown in Fig. 14, the cooling solvent flows in a direction parallel to the X-axis (from the back side to the front side of the page) in the gap formed between the inner cylinder 30 and the first reel layer 400 and the coil 502.

[0066] In the first modified example, as shown in Fig. 14, the inner cylinder 30 is arranged to form a gap that prevents contact with the coil 502 arranged on the first reel layer 400. In the first modified example, unlike the example shown in Fig. 13, a gap is formed that allows the cooling solvent to come into contact with the first reel layer 400, and even in this configuration, the coil 502 can be efficiently cooled by the cooling solvent.

[0067] [Second Modification] FIG. 15 is an enlarged view showing a portion of a cross section perpendicular to the X-axis of the inner cylinder 30 and the structure 40 according to a second modification. In the second modification, the first reel layer 410 includes a support portion 412 that sandwiches and supports the coil 503, and a bottom portion 414 that covers the inner cylinder 30 side of the coil 503. In the second modification, the cooling solvent flows in a direction parallel to the X-axis (from the back side to the front side of the page) through a gap formed between the inner cylinder 30 and the bottom portion 414. In the second modification, the coil 503 is cooled by the cooling solvent through the bottom portion 414. In the modification, the inner cylinder 30 is also arranged to form a gap that does not contact the coil 503. Therefore, the cooling solvent can flow through the gap where the inner cylinder 30 and the coil 502 do not contact each other, thereby enabling the coil 502 to be cooled more efficiently by the cooling solvent.

[0068] [Second embodiment] In the first embodiment, the first coil and the second coil are arranged in parallel. However, the first coil and the second coil may be arranged in series. That is, the first coil and the second coil may be arranged at positions offset from each other in a direction parallel to the X-axis.

[0069] 16, a charged particle beam deflection device 60 according to the second embodiment, in which a first coil and a second coil are arranged in series, will be described. The charged particle beam deflection device 60 according to the second embodiment mainly includes a first deflection device 62, a second deflection device 64, and a connecting member 66 that connects the first deflection device 62 and the second deflection device 64. The first deflection device 62 and the second deflection device 64 may each include various components included in the charged particle beam deflection device 20 according to the first embodiment.

[0070] An internal space 72 having an entrance port 74 at one end and an exit port 76 at the other end is formed inside the charged particle beam deflection device 60. The charged particle beam enters the internal space 72 from the entrance port 74 in the D-axis direction shown in FIG. 16 , is deflected by the first deflection device 62 and the second deflection device 64 in the internal space 72, and exits from the exit port 76.

[0071] The first deflection device 62 is a device that deflects the charged particle beam in a direction perpendicular to the D-axis direction and makes the deflected charged particle beam incident on the second deflection device 64. The first deflection device 62 includes a first structure 620, a first yoke 622, a first inflow member 624, a first outflow member 630, and an inner cylinder 70.

[0072] The inner cylinder 70 has a hollow shape and is configured so that the charged particle beam passes through its interior. In this embodiment, the inner cylinder 70 is shared by the first deflection device 62 and the second deflection device 64. However, the inner cylinder may be configured so that the first deflection device 62 and the second deflection device 64 are independent. An entrance port 74 is formed at one end of the inner cylinder 70, and an exit port 76 is formed at the other end of the inner cylinder 70. The inner cylinder 70 according to the second embodiment has a cylindrical shape. The outer and inner diameters may have linear or non-linear slopes.

[0073] The first structure 620 is configured to deflect the charged particle beam passing through the internal space 72 by a magnetic field. The first structure 620 includes a first stacked structure and a first coil, not shown. The first coil deflects the charged particle beam in a direction different from the D-axis direction by the generated magnetic field. For example, the first coil may deflect the charged particle beam in a direction perpendicular to the D-axis direction.

[0074] The first laminated structure has a hollow shape through which the charged particle beam passes, and includes multiple layers stacked in a direction from the inside to the outside. Between two adjacent layers of the multiple layers, there is a gap through which a cooling solvent can flow. The multiple layers of the first laminated structure include a first coil support layer that supports the first coil.

[0075] The first inflow member 624 is a member for allowing the cooling solvent to flow into the first structure 620. The first inflow member 624 is connected to the connecting member 66. The first inflow member 624 also has a pressing portion 625 that presses the first structure 620 from the outside toward the inside. Inside the first inflow member 624, a space 628 is formed that is surrounded by the end face of the first structure 620, the first inflow member 624, the connecting member 66, and the outer peripheral surface of the inner cylinder 70, and this space 628 is in communication with the gap in the first structure 620. Furthermore, the first inflow member 624 has a hole 626 that is open in the D-axis direction, and this hole 626 is in communication with the space 628.

[0076] The first outflow member 630 is a member for causing the cooling solvent to flow out. The first outflow member 630 includes a pressing portion 634 that presses the first structure 620 from the outside toward the inside, and a covering member 632 that covers the end face of the first structure 620. In the second embodiment, a space 633 is formed that is surrounded by the end face of the first structure 620, the covering member 632, and the outer peripheral surface of the inner cylinder 70. The space 633 communicates with a gap in the first structure 620 and an outlet (not shown).

[0077] In first deflection device 62, cooling solvent flows through first inflow member 624, first structure 620, and first outflow member 630 in the direction of the arrows shown in Fig. 15, thereby cooling the first coil of first structure 620. Specifically, cooling solvent flows into space 628 from hole 626 of first inflow member 624, passes through first structure 620 and space 633 of first outflow member 630, and is discharged from the discharge port. At this time, the cooling solvent flows through the gaps in first structure 620, thereby cooling the first coil.

[0078] The second deflection device 64 is a device that deflects the charged particle beam in the D-axis direction and in a direction different from the direction in which the first deflection device 62 deflects the charged particle beam, and emits the deflected charged particle beam from an exit port 76. The second deflection device 64 includes a second structure 640, a second yoke 642, a second inflow member 644, a second outflow member 650, and an inner cylinder 70.

[0079] The second structure 640 is configured to deflect the charged particle beam passing through the internal space 72 by using a magnetic field. The second structure 640 according to the second embodiment includes a second stacked structure and a second coil, not shown. The second coil generates a magnetic field to deflect the charged particle beam deflected by the first deflection device 62 in a direction different from the D-axis direction and the direction in which the first deflection device 62 deflects the charged particle beam. The second coil may, for example, deflect the charged particle beam in a direction perpendicular to the D-axis direction and perpendicular to the direction in which the first deflection device 62 deflects the charged particle beam.

[0080] The second laminated structure has a hollow shape through which the charged particle beam passes, and includes multiple layers stacked in a direction from the inside to the outside. Between two adjacent layers of the multiple layers, there is a gap through which a cooling solvent can flow. The multiple layers of the second laminated structure include a second coil support layer that supports the second coil.

[0081] The second inflow member 644 is a member for allowing the cooling solvent to flow into the second structure 640. The second inflow member 644 includes a covering member 646 that covers the end face of the second structure 640, and a pressing portion 647 that presses the second structure 640 from the outside toward the inside. In the second embodiment, a space 649 is formed that is surrounded by the end face of the second structure 640, the covering member 646, and the outer peripheral surface of the inner cylinder 70. This space 649 is in communication with the gap in the second structure 640. Furthermore, the second inflow member 644 has a hole 648 that is open in the D-axis direction, and this hole 648 is in communication with the space 649.

[0082] The second outflow member 650 is a member for causing the cooling solvent to flow out. The second outflow member 650 is connected to the connecting member 66. The second outflow member 650 may also function as a pressing part that presses the second structure 640 from the outside toward the inside. A space 652 is formed that is surrounded by the end face of the second structure 640, the second outflow member 650, the connecting member 66, and the outer peripheral surface of the inner cylinder 70. The space 652 is in communication with a gap in the second structure 640 and an outlet (not shown).

[0083] In second deflection device 64, the cooling solvent flows in the direction of the arrows shown in Fig. 15 through second inflow member 644, second structure 640, and second outflow member 650, thereby cooling the second coil of second structure 640. Specifically, the cooling solvent flows into space 649 from hole 648 of second inflow member 644, passes through second structure 640 and space 652, and is discharged from the discharge port. At this time, the cooling solvent flows through the gaps in second structure 640, thereby cooling the second coil.

[0084] The above has described the charged particle beam deflection device 60 according to the second embodiment. In the second embodiment, an example has been described in which the first yoke 622 of the first deflection device 62 and the second yoke 642 of the second deflection device 64 are separate bodies, but the present invention is not limited to this, and the yokes of the first deflection device 62 and the second deflection device 64 may be integrated and connected to each other.

[0085] Furthermore, the path through which the cooling solvent flows is not limited to the example described above. For example, a hole that connects space 628 and space 652 may be provided in connecting member 66. In this case, the cooling solvent that flows into second deflection device 64 passes through the hole provided in connecting member 66, flows into first deflection device 62, and is discharged from space 633 to the outside.

[0086] Furthermore, both of the two spaces formed by the connecting member 66 (i.e., the space 628 of the first deflection device 62 and the space 652 of the second deflection device 64) may be used for the inflow of the cooling solvent. In this case, the cooling solvent that has flowed into the space 652 of the second deflection device 64 may pass through the space 649 and be discharged to the outside through the hole 648.

[0087] [Laminated structure alignment] When aligning the structure 40 with respect to the isocenter, the reference point for aligning the structure 40 can be the inflow member 24. Therefore, the structure 40 can be aligned using the inflow member 24 as a reference. An example of a method for aligning the structure 40 will be described below with reference to FIGS. 17 and 18. FIG. 17 is a view of the aligned structure 40 as seen from the emission side of the charged particle beam. FIG. 18 is an enlarged view showing the inner cylinder 30, outer cylinder 32, and structure 40 aligned with the emission-side pressing portion 241 by the positioning pins 28.

[0088] 17, the structure 40 and the inner cylinder 30 are fixed to the output side pressing portion 241 by four positioning pins 28. The number of positioning pins 28 may be three or less, or five or more.

[0089] Each layer 491-498 of the structure 40 has a cutout portion formed along the radial direction. The inner cylinder 30 has a screw hole for fixing the positioning pin 28 to the inner cylinder 30. As shown in Fig. 18, the positioning pin 28 is engaged with the cutout portion, and the cutout portions and the screw holes of the inner cylinder 30 are all aligned in the radial direction, so that each layer of the structure 40 (each reel layer and each water channel layer) is stacked with high precision.

[0090] Because the positioning pins 28 are engaged with the structure 40, the inner cylinder 30, the structure 40, and the outer cylinder 32 in close contact with the structure 40 are aligned with the output-side pressing portion 241. Furthermore, when multiple reel layers each provided with a coil are stacked as in this embodiment, the arrangement of the positioning pins 28 ensures an appropriate relative positional relationship between the first coil and the second coil.

[0091] The configuration of the positioning pin 28 will be described in more detail with reference to Fig. 18. As shown in Fig. 18, the positioning pin 28 includes a first fixed portion 280, a fixing portion 286, and a second fixed portion 288. The first fixed portion 280, the fixing portion 286, and the second fixed portion 288 are integral with each other.

[0092] The first fixed part 280 has screw holes 282, 284, and by passing screws through these screw holes 282, 284, the first fixed part 280 is fixed to a desired position on the emission side pressing part 241. Furthermore, the second fixed part 288 has screw holes (not shown), and by passing screws through these screw holes, the second fixed part 288 is fixed to the inner tube 30. The fixing part 286 is a plate-like member that connects the first fixed part 280 and the second fixed part 288.

[0093] A cutout portion is provided in each of layers 491 to 498 of structure 40, and fixing portion 286 engages with the cutout portion. By engaging structure 40 with four positioning pins 28 in this manner, structure 40 and outer cylinder 32 in close contact with structure 40 are aligned with output-side pressing portion 241. By using positioning pins 28 in this manner, assembly of laminated structure 42 can be facilitated by stacking the laminated structure 42 with high positional accuracy.

[0094] An example of the flow of aligning the outer cylinder 32, the structure 40, the output-side pressing portion 241, etc. will be described below. Here, an example will be described in which a simulated member simulating the inflow member 24 and a positioning pin for the simulated member simulating the positioning pin 28 are used.

[0095] First, each layer of the inner tube 30 and the structure 40 (each reel layer and each water channel layer) is sequentially fixed or engaged with the positioning pins for the simulation member fixed to the simulation member, and the layers are bonded and fixed. After the structure 40 is aligned with the simulation member in this manner, the positioning pins for the simulation member are removed from the simulation member. Then, the simulation member is replaced with the inflow member 24, and the inner tube 30, the structure 40, the outer tube 32, and the output-side pressing portion 241 are fixed to the inflow member 24 with the positioning pins 28. This positions the structure 40 and other components accurately relative to the inflow member 24. Therefore, the coil of the structure 40 is fixed in an appropriate position relative to the inflow member 24. Assembly in this manner allows each layer to be positioned accurately relative to the inflow member 24 simply and reliably.

[0096] [supplement] The present invention has been described above based on the embodiments. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of the components and treatment processes, and that such modifications are also within the scope of the present invention.

[0097] In the above embodiment, an example has been described in which the charged particle beam deflection device 20 is provided in the irradiation nozzle 16. However, the charged particle beam deflection device is not limited to this, and may be provided in devices for deflecting various charged particle beams, such as the charged particle beam adjusting means 122.

[0098] In the above-described embodiment, an example has been described in which the incident-side pressing portion 226 and the output-side pressing portion 241 press the incident-side end and the output-side end of the outer circumferential surface of the laminated structure, respectively. The positions of the laminated structure pressed by the pressing portions are not limited to these ends. For example, the pressing portion may press the central region of the outer circumferential surface of the laminated structure.

[0099] In the above-described embodiment, the first coil and the second coil generate magnetic fields in directions that are substantially perpendicular to each other. However, the present invention is not limited to this, and the first coil and the second coil may generate magnetic fields in directions that are shifted from the perpendicular direction to each other within a range that allows scanning of the charged particle beam.

[0100] In the above embodiment, an example has been described in which the shapes of the inner tube 30, the layers constituting the laminated structure 42, and the outer tube 32 are circular in cross section perpendicular to the X axis. However, these shapes are not limited to circular and may be various shapes such as elliptical or rectangular.

[0101] In the above-described embodiment, an example has been described in which the total length of the outer cylinder 32 in the X-axis direction is approximately the same as the total length of the structure 40 in the X-axis direction. However, this is not limited to this, and the total length of the outer cylinder in the X-axis direction may be different from the total length of the structure in the X-axis direction. For example, the total length of the outer cylinder in the X-axis direction may be longer than the total length of the structure in the X-axis direction, and the outer cylinder may protrude outward from the end face of the structure. In this case, the protruding portion of the outer cylinder may be pressed inward from the outside using a pressing unit, thereby pressing the structure 40.

[0102] In the above-described embodiment, the outflow member 22 and the inflow member 24 are each formed of a combination of multiple members. However, the present invention is not limited to this, and each of the outflow member 22 and the inflow member 24 may be formed of a single member. [Explanation of symbols]

[0103] REFERENCE SIGNS LIST 1 Charged particle beam irradiation device, 14 Deflection electromagnet, 16 Irradiation nozzle, 20 Charged particle beam deflection device, 22 Outflow member, 24 Inflow member, 30 Inner cylinder, 32 Outer cylinder, 40 Structure, 42 Laminated structure, 43 End surface, 44 End surface, 50 First coil, 52 Second coil, 222 Incident side protrusion, 224 Incident side covering portion, 226 Incident side pressing portion, 240 Exit side end, 241 Exit side pressing portion, 243 Exit side protrusion, 244 Hole, 300 Internal space

Claims

1. a laminated structure having a hollow shape through which a charged particle beam passes, the laminated structure having a plurality of layers laminated in a direction from the inside to the outside; a first coil for deflecting the charged particle beam in a first direction different from a traveling direction of the charged particle beam; a second coil for deflecting the charged particle beam in a second direction different from the first direction; a yoke located on an outer peripheral surface of the laminated structure; an inflow member into which a coolant for cooling the first coil or the second coil flows, the plurality of layers includes a first coil support layer that supports the first coil and a second coil support layer that supports the second coil; the yoke is located closer to the center than both ends of the laminated structure, the inflow member is provided at one end of the laminated structure and has a hole through which the cooling liquid flows, The hole is formed in a direction from an end face of the end of the laminated structure where the inflow member is provided toward the center of the laminated structure. Charged particle beam deflection device.

2. an inner cylinder having a hollow shape and configured to allow the charged particle beam to pass through the inside thereof; the laminated structure is provided so as to cover the outer peripheral surface of the inner cylinder, the inflow member has an internal space communicating with the hole and the gap in the laminated structure, The inner cylinder is provided to close an opening of the internal space on the inner side of the laminated structure.

2. The charged particle beam deflection device according to claim 1.

3. an outlet member through which the cooling liquid flows out, the outlet member being provided at an end of the laminated structure opposite to the end at which the inflow member is provided; The outflow member is configured to discharge the coolant that has flowed into the outflow member from the internal space through gaps in the laminated structure to the outside.

3. The charged particle beam deflection device according to claim 2.

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