A cooling system for a coupled linear accelerator

Abstract

The present invention provides a cooling system for a coupled linear accelerator, comprising a coupling component and two accelerators, wherein the coupling component couples the two accelerators to form a coupled linear accelerator, wherein cooling channels for cooling medium to flow are arranged in the coupling component and the accelerator; the cooling channels are connected to an external cooling medium conveying device; according to the characteristics of the coupled linear accelerator, the present invention cools the coupling component and the accelerator separately, so as to control the temperature rise, deformation and frequency drift of the coupled linear accelerator within a controllable range, thereby ensuring the operation stability of the coupled linear accelerator.

Description

Technical Field

[0001] The invention relates to the field of accelerators, and in particular to a cooling system for a coupled linear accelerator. Background Art

[0002] A linear accelerator is a device used to accelerate a particle beam to increase the beam energy. In order to achieve higher beam energy, multiple linear accelerators are usually connected in series, but each linear accelerator requires a separate power source to feed RF power, which is costly.

[0003] In order to save power source, the applicant coupled two linear accelerators through a coupling member in the scheme of the prior invention patent application with application number 2024114547741 to form a coupled linear accelerator with a complete acceleration cavity. When the coupled linear accelerator is in operation, the radio frequency power provided by the power source will form an electromagnetic field in the acceleration cavity. The electromagnetic field will cause the high-frequency components (such as drift tubes) on the surface of the acceleration cavity and in the acceleration cavity to generate current, triggering the Joule heating effect, thereby causing the acceleration cavity to heat up and produce thermal deformation. The thermal deformation of the cavity will change the cavity frequency and reduce the performance of the acceleration device. Therefore, in order to ensure the normal operation of the acceleration device, a cooling system needs to be set up to dissipate heat from the acceleration device.

[0004] At present, the cooling of the acceleration cavity generally adopts the solution of setting multiple independent liquid cooling channels along the axial direction of the cavity, but this solution is not suitable for coupled linear accelerators. Specifically, since the coupled linear accelerator is formed by coupling a coupling device and two linear accelerators, the acceleration cavity of the coupled linear accelerator is a three-section cavity; compared with the traditional single cavity, the electromagnetic field distribution in the three-section cavity will be more complex and more sensitive to structural deformation; in addition, since the RF power of the power source is fed into the acceleration cavity through the coupling device, in order to achieve the coupled resonance of the electromagnetic fields of the front and rear cavities, it is necessary to improve the uniformity of the electric field distribution in the middle cavity (i.e., the cavity of the coupling device) as much as possible, thereby improving the electric field uniformity of the entire acceleration cavity. Among them, the uniformity of the electric field distribution is closely related to the radii of the front and rear sections of the cavity; in addition, the change in the radius of the middle section of the cavity will also cause the resonant frequency of the entire acceleration cavity to change. If a liquid cooling channel is set along the axial direction of the cavity for cavity cooling, the coolant will gradually heat up along the axial direction, resulting in large differences in the temperature and deformation degree of each section of the cavity, which will in turn cause problems such as uneven electric field distribution and cavity frequency detuning, affecting the operating stability of the acceleration device. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a cooling system for a coupled linear accelerator, which can effectively shorten the temperature difference and deformation degree of each section of the cavity, so as to improve the operating stability of the coupled linear accelerator.

[0006] To achieve the above-mentioned purpose, the present invention provides a cooling system for a coupled linear accelerator, comprising a coupling member and two accelerators, wherein the coupling member couples the two accelerators to form a coupled linear accelerator, and cooling channels for cooling medium to flow are arranged in the coupling member and the accelerator, and the cooling channels are connected to an external cooling medium conveying device.

[0007] Preferably, the coupling member has a coupling shell, and a first cooling channel is provided on the shell wall of the coupling shell; the first cooling channel is an annular structure arranged circumferentially around the coupling shell, and a first liquid inlet and a first liquid outlet connected to the first cooling channel are provided on the outer surface of the coupling shell.

[0008] Preferably, a magnet drift tube is provided in the coupling member; the magnet drift tube comprises a magnet drift tube body and a first support rod, and the magnet drift tube body is installed in the coupling shell through the first support rod; a second cooling channel is provided on the tube wall of the magnet drift tube body, the second cooling channel is an open annular structure circumferentially arranged around the magnet drift tube body, and a first liquid inlet channel and a first liquid outlet channel are respectively provided at both ends of the second cooling channel; the first liquid inlet channel and the first liquid outlet channel are located in the first support rod.

[0009] Preferably, the accelerator has an accelerator housing, a plurality of third cooling channels are arranged in the housing wall of the accelerator housing; the third cooling channels extend along the axial direction of the accelerator housing, and a second liquid inlet and a second liquid outlet are respectively arranged at both ends of the third cooling channels.

[0010] Preferably, a plurality of drift tubes are provided in the accelerator; the drift tubes include a drift tube body and two second support rods symmetrically arranged on the drift tube body; the drift tube body is installed in the accelerator housing through the second support rods; a fourth cooling channel is provided on the tube wall of the drift tube body, and the fourth cooling channel is a closed annular structure circumferentially arranged around the drift tube body; a fifth cooling channel connected to the fourth cooling channel is provided in the second support rod, and the fifth cooling channel extends along the second support rod to the outside of the accelerator; one of the two fifth cooling channels is a liquid inlet channel, and the other is a liquid outlet channel.

[0011] Preferably, a flow guide is provided at the connection point between the fourth cooling channel and the liquid inlet channel; the flow guide is located on the inner wall of the fourth cooling channel.

[0012] Preferably, an end cover is provided at one end of the accelerator away from the coupling member, and a sixth cooling channel is provided in the end cover; the sixth cooling channel is an annular structure coaxially arranged with the end cover, and a third liquid inlet and a third liquid outlet connected to the sixth cooling channel are provided on the end surface of the end cover away from the coupling member.

[0013] Preferably, the sixth cooling channel comprises an inner ring channel with an opening and two outer semi-ring channels; both ends of the inner ring channel are respectively connected to the two outer semi-ring channels, and the free ends of the two outer semi-ring channels are respectively connected to the third liquid inlet and the third liquid outlet.

[0014] Preferably, a bunching groove body is formed at one end of the end cover close to the coupling member, and a seventh cooling channel is provided at one end of the bunching groove body away from the end cover; the seventh cooling channel is an annular structure coaxially arranged with the bunching groove body, and a fourth liquid inlet and a fourth liquid outlet connected to the seventh cooling channel are provided on the inner surface of one end of the bunching groove body away from the end cover.

[0015] Preferably, a tuner is provided in the accelerator, and an eighth cooling channel is provided on the tuner; the eighth cooling channel is an annular structure arranged circumferentially around the tuner, and a second liquid inlet channel and a second liquid outlet channel connected to the eighth cooling channel are provided on the tuner; the second liquid inlet channel and the second liquid outlet channel extend along the axial direction of the tuner.

[0016] Preferably, the shortest distance between one end of the accelerator housing close to the coupling member and the third cooling channel on the accelerator housing is 50 mm, and the shortest distance between one end of the accelerator housing away from the coupling member and the third cooling channel on the accelerator housing is 50 mm.

[0017] Preferably, the first cooling channel is an open ring structure, and the distance between the two ends of the first cooling channel is 40 mm.

[0018] As described above, the cooling system of the coupled linear accelerator according to the present invention has the following beneficial effects:

[0019] Since the coupled linear accelerator is formed by coupling and connecting two accelerators through a coupling member, the acceleration cavity of the coupled linear accelerator is a three-section cavity, which is composed of a coupling shell and an accelerator shell coaxially arranged at both ends of the coupling shell; since the electromagnetic field distribution inside the three-section cavity is relatively complex and highly sensitive to structural deformation; in order to ensure the thermal stability of the entire acceleration cavity, the present application arranges at least one first cooling channel arranged around the circumference of the coupling shell, and evenly arranges a plurality of linear fourth cooling channels along the circumference of each accelerator shell to achieve segmented cooling of the acceleration cavity; compared with the traditional single axial cooling channel solution, the present application has a better cooling effect, can effectively reduce the temperature difference and deformation degree of each segment shell, thereby improving the operating stability of the coupled linear accelerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a three-dimensional perspective view of the coupled linear acceleration device involved in this application.

[0021] Figure 2 It is a side view of the coupled linear accelerator.

[0022] Figure 3 for Figure 2 AA section view.

[0023] Figure 4 It is a structural schematic diagram of the first cooling channel in the coupling shell.

[0024] Figure 5 This is a three-dimensional image of a magnet drift tube.

[0025] Figure 6 This is a cross-sectional view of the magnet drift tube.

[0026] Figure 7 It is a schematic diagram of the structure of the third cooling channel in the accelerator housing.

[0027] Figure 8 A three-dimensional image of the drift tube.

[0028] Fig. 9 This is the front view of the drift tube.

[0029] Fig.10 for Fig. 9 BB section view.

[0030] Fig.11 for Fig.10 Enlarged view of point C.

[0031] Fig.12 An isometric half-section view of the drift tube.

[0032] Fig.13This is a schematic diagram of a bunching slot body being arranged on an end cover.

[0033] Fig.14 It is a schematic diagram of the structure of the sixth cooling channel in the end cover.

[0034] Fig.15 It is a schematic diagram of the structure of the seventh cooling channel in the bunching tank body.

[0035] Fig.16 This is a schematic diagram of the structure of the eighth cooling channel in the tuner.

[0036] Fig.17 This is the flow velocity distribution diagram of the cooling medium inside the drift tube before the guide piece is installed.

[0037] Fig.18 This is the distribution diagram of the convective heat transfer coefficient inside the drift tube before the guide piece is installed.

[0038] Fig.19 This is the flow velocity distribution diagram of the cooling medium inside the drift tube after the guide piece is installed.

[0039] Fig. 20 This is the distribution diagram of the convective heat transfer coefficient inside the drift tube after the guide piece is installed.

[0040] Fig.21 This is a schematic diagram of the heat generation of the coupled linear accelerator working at an ambient temperature of 20°C.

[0041] Fig. 22 This is a schematic diagram of the heat generation of the internal components of the coupled linear accelerator when it is operating at an ambient temperature of 20°C.

[0042] Fig.23 Schematic diagram of the deformation of the internal components of the coupled linear accelerator when it is working at an ambient temperature of 20°C.

[0043] Fig.24 Schematic diagram of thermal stress distribution of internal components of the coupled linear accelerator when it operates at an ambient temperature of 20°C.

[0044] Fig.25 Schematic diagram of the variation of multiple physical parameters with power.

[0045] Description of reference numerals:

[0046] Coupling member 1, coupling housing 11, first liquid inlet 11a, first liquid outlet 11b, magnet drift tube 12, magnet drift tube body 121, first beam hole 1211, first support rod 122, first liquid inlet channel 1221, first liquid outlet channel 1222;

[0047] Accelerator 2, accelerator housing 21, second liquid inlet 21a, second liquid outlet 21b, drift tube 22, drift tube body 221, second beam hole 2211, second support rod 222, flow guide 223, end cover 23, third liquid inlet 23a, third liquid outlet 23b, focusing tank 24, fourth liquid inlet 24a, fourth liquid outlet 24b, feed-through hole 241, tuner 25, second liquid inlet channel 25a, second liquid outlet channel 25b;

[0048] The first cooling channel 31 , the second cooling channel 32 , the third cooling channel 33 , the fourth cooling channel 34 , the fifth cooling channel 35 , the sixth cooling channel 36 , the inner ring channel 361 , the outer semi-ring channel 362 , the seventh cooling channel 37 , the eighth cooling channel 38 , and the support seat 4 . DETAILED DESCRIPTION

[0049] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0050] It should be noted that the structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0051] The present application provides a cooling system for a coupled linear accelerator, which is used to improve the operating stability of the coupled linear accelerator. The structure of the coupled linear accelerator is as follows: Figures 1 to 5 As shown, it includes a coupling member 1 and two accelerators 2; the coupling member 1 is coaxially arranged between the two accelerators 2, and couples the two accelerators 2 to form a complete acceleration cavity. The acceleration cavity is a three-section cavity, which includes a coupling shell 11 of the coupling member 1 and an accelerator shell 21 of the two accelerators 2; a magnet drift tube 12 is arranged in the coupling shell 11, and the first beam hole 1211 of the magnet drift tube 12 is coaxially arranged with the coupling shell 11 to form a beam channel of a coupled linear acceleration device in the acceleration cavity. The accelerator 2 is preferably a DTL accelerator (H-type drift tube accelerator).

[0052] During actual use, the radio frequency power of the power source will be fed into the accelerating cavity through the coupling element 1 to form a resonant space and a uniform electromagnetic field in the accelerating cavity. The electromagnetic field will cause the high-frequency components (such as the drift tube) on the surface of the accelerating cavity and in the accelerating cavity to generate current, triggering the Joule heating effect, thereby causing the accelerating cavity to heat up and produce thermal deformation. The thermal deformation of the cavity will change the cavity frequency and electromagnetic field distribution, thereby reducing the performance of the coupled linear accelerator.

[0053] However, compared with a single cavity, the electromagnetic field distribution inside the three-stage acceleration cavity is more complex and more sensitive to structural errors. For example, when the radius of the coupling shell 11 changes, the resonant frequency and mode spacing of the acceleration cavity (the mode spacing is the resonant frequency difference between the 0 resonance mode and the π resonance mode) will change accordingly; for another example, when the radius of the accelerator shell 21 changes, the resonant frequency and electromagnetic field distribution of the entire acceleration cavity will change. Therefore, the existing accelerator cooling scheme is not suitable for coupled linear acceleration devices, and there are situations where cooling is not in place and cooling is uneven.

[0054] Based on this, the present application provides a cooling system dedicated to a coupled linear accelerator to control the temperature rise, deformation and frequency drift of the coupled linear accelerator within a controllable range, thereby ensuring the normal operation of the coupled linear accelerator.

[0055] like Figure 1 As shown, the cooling system of the coupled linear accelerator includes cooling channels arranged in the coupling member 1 and the accelerator 2; each cooling channel is connected to an external cooling medium conveying device so that the cooling medium flows in each cooling channel and takes away excess heat, thereby realizing separate circulation cooling of the coupling member 1 and each accelerator 2.

[0056] It should be noted that the cooling medium conveying device can provide low-temperature cooling medium for the cooling channel. The low-temperature cooling medium flows in the cooling channel to absorb the heat of the components in the cooling channel and is converted into high-temperature cooling medium to be discharged from the coupled linear accelerator; the discharged high-temperature cooling medium can be directly discharged through the cooling medium conveying device. Of course, the cooling medium conveying device can also be used to cool the discharged high-temperature cooling medium to achieve the recycling of the cooling medium, thereby achieving the purpose of reducing cooling costs; in this case, the cooling medium conveying device is a cooling medium circulation device.

[0057] According to the structural characteristics of the coupled linear accelerator, the present application performs independent circulation cooling on the coupling member 1 and the accelerator 2, thereby effectively improving the cooling effect of the coupled linear accelerator.

[0058] It should be noted that the cooling medium includes but is not limited to cooling water, cooling oil, phase change medium and other cooling fluids capable of heat exchange. Based on cost considerations, the cooling medium of this embodiment is cooling water.

[0059] like Figure 4 As shown, a first cooling channel 31 is provided in the shell wall of the coupling shell 11. The first cooling channel 31 is an annular cooling channel circumferentially arranged around the coupling shell 11, and a first liquid inlet 11a and a first liquid outlet 11b connected to the first cooling channel 31 are provided on the outer surface of the coupling shell 11. In the present embodiment, the first cooling channel 31 is a single-ring structure to reduce the difficulty of processing the first cooling channel 31.

[0060] It should be noted that the number of first cooling channels 31 provided on the coupling shell 11 can be determined according to actual conditions and is not limited thereto. In the present embodiment, two first cooling channels 31 are provided in the cavity wall of the coupling shell 11 at intervals along the axial direction, and the shortest axial spacing between each first cooling channel 31 and the end of the coupling shell 11 is 30 mm.

[0061] Since the wall thickness of the coupling housing 11 is 40 mm, in this embodiment, the radius of the first cooling channel 31 is preferably set to 8 mm.

[0062] like Figure 4 As shown, the first cooling channel 31 is an open ring structure as a whole, and the first liquid inlet 11a and the first liquid outlet 11b are respectively arranged at the two ends of the first cooling channel 31 to connect with the external cooling medium conveying device; at this time, the first cooling channel 31 belongs to a single-thread water channel (that is, there is only one water channel connecting the first liquid inlet 11a and the first liquid outlet 11b in the first cooling channel 31).

[0063] It should be noted that the distance between the two ends of the first cooling channel 31 can be determined according to the radius of the coupling housing 11, and is not limited thereto. In the present embodiment, the distance between the two ends of the first cooling channel 31 is 40 mm.

[0064] Of course, in other embodiments, the first cooling channel 31 may also be a closed annular structure, and the first liquid inlet 11a and the first liquid outlet 11b are symmetrically arranged about the center of the first cooling channel 31; in this case, the first cooling channel 31 is a double-threaded water channel (i.e., the first cooling channel 31 has two semi-annular water channels connecting the first liquid inlet 11a and the first liquid outlet 11b). In order to prevent the cooling water in one water channel from flowing back to the first liquid inlet 11a through another water channel, thereby affecting the uniformity of the cooling water flow rate distribution in the first cooling channel 31 and further affecting the convection heat transfer coefficient, a guide member may be provided at the connection between the first cooling channel 31 and the first liquid inlet 11a, so as to use the guide member to divert the cooling water flowing into the first liquid inlet 11a into two identical paths, so as to eliminate the cooling water reflux phenomenon.

[0065] like Figure 3 , Figure 5 and Figure 6 As shown, the magnet drift tube 12 includes a magnet drift tube body 121 and a first support rod 122 vertically fixed on the magnet drift tube body 121; the first beam hole 1211 is coaxially arranged on the magnet drift tube body 121, and the magnet drift tube body 121 is coaxially installed in the coupling housing 11 through the first support rod 122; since the magnet drift tube 12 is a high-frequency component and the magnet drift tube 12 passes through a high-intensity magnetic field area, the power density and heat generation phenomenon on its surface are relatively obvious. In order to ensure the normal operation of the magnet drift tube 12, a second cooling channel 32 can be arranged on the tube wall of the magnet drift tube body 121; the second cooling channel 32 is an open annular channel 32 arranged circumferentially around the magnet drift tube body 121. structure, and a first liquid inlet channel 1221 and a first liquid outlet channel 1222 are respectively provided at both ends of the second cooling channel 32; the first liquid inlet channel 1221 and the first liquid outlet channel 1222 are both located in the first support rod 122, and extend along the axial direction of the first support rod 122 to the end surface of the free end of the first support rod 122; in this way, external cooling water can flow into the second cooling channel 32 along the first liquid inlet channel 1221, and flow out from the first liquid outlet channel 1222 to complete the cooling of the magnet drift tube 12; at this time, the second cooling channel 32 belongs to a single-thread water channel (that is, there is only one water channel connecting the first liquid inlet channel 1221 and the first liquid outlet channel 1222 in the second cooling channel 32).

[0066] In this embodiment, the distance between the outer wall of the second cooling channel 32 and the outer wall of the magnet drift tube body 121 is 7 mm, so as to ensure that the magnet drift tube 12 has a certain mechanical strength.

[0067] like Figure 7As shown, a plurality of third cooling channels 33 are evenly distributed in the circumferential direction of the shell wall of the accelerator housing 21, and the third cooling channels 33 are linear cooling channels extending along the axial direction of the accelerator housing 21; a second liquid inlet 21a and a second liquid outlet 21b are respectively provided at both ends of the third cooling channel 33, and the second liquid inlet 21a and the second liquid outlet 21b both extend to the outer surface of the accelerator housing 21 to connect with an external cooling medium delivery device.

[0068] It should be noted that the number and radius size of the third cooling channels 33 provided on the accelerator housing 21 can be comprehensively determined based on parameters such as the radius and wall thickness of the accelerator housing 21, and there is no limitation on this; when the radius of the accelerator housing 21 is 300 mm to 320 mm, and the wall thickness of the accelerator housing 21 is 40 mm, 8 third cooling channels 33 are provided on the accelerator housing 21, and the radius of the third cooling channel 33 is 8 mm.

[0069] In this embodiment, the axial spacing between the end of the third cooling channel 33 and the corresponding side end of the accelerator housing 21 where the third cooling channel 33 is located is 50 mm (that is, the shortest spacing between the end of the accelerator housing 21 close to the coupling member 1 and the third cooling channel 33 on the accelerator housing 21 is 50 mm, and the shortest spacing between the end of the accelerator housing 21 away from the coupling member 1 and the third cooling channel 33 on the accelerator housing 21 is 50 mm) to ensure the cooling effect of the accelerator housing 21.

[0070] According to the functions and characteristics of the accelerator 2 and the coupling member 1, the present application sets different forms of cooling channels on the coupling shell 11 and the accelerator shell 21 to achieve segmented cooling of the entire acceleration cavity. Compared with the traditional single axial cooling channel solution, the present application has a better cooling effect and can effectively suppress the temperature rise and deformation of each segment of the shell, thereby shortening the temperature difference and deformation degree of each segment of the shell, ensuring that the frequency drift is within a controllable range, so as to ensure the operating stability of the coupled linear accelerator.

[0071] It is understandable that the accelerator 2 in the coupled linear acceleration device is a drift tube accelerator or a heavy ion accelerator or other types of acceleration structures, which are not limited to this; Figures 1 to 3 As shown, in the present application, the accelerator 2 is a drift tube linear accelerator, which includes a plurality of drift tubes 22 located in an accelerator housing 21; the second beam hole 2211 of each drift tube 22 is coaxially arranged with the first beam hole 1211 of the magnet drift tube 12 to form a beam channel.

[0072] like Figures 8 to 12As shown, the drift tube 22 includes a drift tube body 221 and two second support rods 222 symmetrically arranged on the drift tube body 221; the second beam hole 2211 is coaxially arranged on the drift tube body 221, and the drift tube body 221 is coaxially installed in the accelerator housing 21 through the second support rods 222; since the drift tube 22 is a high-frequency component, it will generate more heat when working in the electromagnetic field; in order to cool the drift tube 22, the present application sets a fourth cooling channel 34 on the tube wall of the drift tube body 221; the fourth cooling channel 34 is set circumferentially around the drift tube body 221 A closed annular structure is provided; each second support rod 222 is provided with a fifth cooling channel 35 connected to the fourth cooling channel 34, and the fifth cooling channel 35 extends along the axial direction of the second support rod 222 to the end surface of the free end of the second support rod 222, so that it is connected to the outside of the accelerator housing 21; at this time, one of the two fifth cooling channels 35 is a liquid inlet channel, and the other is a liquid outlet channel, and the connection between the fourth cooling channel 34 and the liquid inlet channel is the water inlet of the fourth cooling channel 34, and the connection between the fourth cooling channel 34 and the liquid outlet channel is the water outlet of the fourth cooling channel 34.

[0073] It should be noted that the radius of the fourth cooling channel 34 is determined according to the size of the drift tube body 221; when the wall thickness of the drift tube body 221 is 15 mm, the diameter of the fourth cooling channel 34 is 2.5 mm.

[0074] In order to ensure the mechanical strength of the drift tube body 221 , the axial distance between the two ends of the fourth cooling channel 34 and the corresponding side ends of the drift tube body 221 is 5 mm.

[0075] Depend on Fig.11 It can be seen that the fourth cooling channel 34 is actually a parallel water channel composed of two semi-ring water channels, which belongs to a double-thread water channel; when the cooling water flows to the water inlet of the fourth cooling channel 34 through the liquid inlet channel, the cooling water will be divided into two paths, flowing along the two semi-ring water channels respectively, and converge at the water outlet of the fourth cooling channel 34. The cooling water converged at the water outlet is discharged through the liquid outlet channel to complete the heat exchange.

[0076] However, it is found in actual use that at the water inlet of the fourth cooling channel 34, the cooling water at the water outlet of the fourth cooling channel 34 will reflux (that is, part of the cooling water in one half of the ring water channel will flow back to the water inlet of the fourth cooling channel 34 along the other half of the ring water channel), resulting in a deviation in the cooling water flow rate in the fourth cooling channel 34, resulting in an uneven water flow rate in the fourth cooling channel 34, thereby affecting the convective heat transfer coefficient; in order to alleviate or eliminate the problem of uneven water flow rate caused by cooling water reflux, such as Fig.11As shown, a guide member 223 is provided at the connection point between the fourth cooling channel 34 and the liquid inlet channel, the guide member 223 is located on the inner wall of the fourth cooling channel 34, and the guide member 223 is symmetrically arranged about the axial center line of the second support rod 222; by arranging the guide member 223, the water flow at the water inlet of the fourth cooling channel 34 is smoothly divided into two identical parts, so as to ensure that the cooling water flow rate and flow velocity flowing through the two semi-annular water channels remain consistent, thereby suppressing or eliminating the reflux phenomenon of the cooling water.

[0077] It should be noted that the flow guide 223 is a plate-shaped structure or a block-shaped structure, which is not limited as long as it can play a flow-guiding role.

[0078] In order to verify the influence of the guide member 223 on the flow velocity and convection heat transfer coefficient of the cooling medium in the drift tube, a simulation analysis was performed on the drift tube 22 before and after the guide member 223 was installed. Fig.11 , Fig.17 and Fig.19 It can be seen that after the flow guide 223 is provided, the maximum flow velocity in the liquid outlet channel decreases, and the flow velocity in the reflux area increases, which makes the flow velocity distribution of the drift tube 22 more uniform. Fig.18 and Fig. 20 It can be seen that after the flow guide 223 is provided, the convective heat transfer coefficient is improved, which means that after the flow guide 223 is provided, the cooling effect of the drift tube 22 is improved.

[0079] In an optional embodiment, if Figure 3 and Fig.13 As shown, an end of the accelerator housing 21 away from the coupling member 1 is provided with an end cover 23, and a flow hole for the particle beam to pass through is provided on the end cover 23; during the operation of the acceleration device, current will be generated on the surface of the end cover 23, causing Joule heating effect; in order to prevent the heat generated by the end cover 23 from being transferred to the acceleration cavity, the end cover 23 needs to be cooled.

[0080] Specifically, Fig.14 As shown, a sixth cooling channel 36 is provided in the end cover 23; the sixth cooling channel 36 is an annular structure coaxially arranged with the end cover 23; a third liquid inlet 23a and a third liquid outlet 23b connected to the sixth cooling channel 36 are provided on the end surface of the end cover 23 away from the coupling member 1, so as to facilitate docking with an external cooling medium conveying device.

[0081] like Fig.14 As shown, the sixth cooling channel 36 is an open ring structure as a whole, and the third liquid inlet 23a and the third liquid outlet 23b are respectively arranged at the two ends of the sixth cooling channel 36; at this time, the sixth cooling channel 36 belongs to a single-thread water channel (that is, there is only one water channel in the sixth cooling channel 36 connecting the third liquid inlet 23a and the third liquid outlet 23b).

[0082] In an optional embodiment, the sixth cooling channel 36 is a single-ring structure.

[0083] In an optional embodiment, the sixth cooling channel 36 is a double-ring structure, which includes an inner ring channel 361 with an opening and two outer semi-ring channels 362, and the two ends of the inner ring channel 361 are respectively connected to the two outer semi-ring channels 362; the cooling effect of the end cover 23 is improved by the double-ring parallel water channel structure.

[0084] It should be noted that the radius of the sixth cooling channel 36 can be determined according to the thickness of the end cover 23. In this embodiment, the radius of the sixth cooling channel 36 is 8 mm.

[0085] Of course, in other embodiments, the sixth cooling channel 36 may also be a closed ring structure, and the third liquid inlet 23a and the third liquid outlet 23b are symmetrically arranged about the center of the sixth cooling channel 36; in this case, the sixth cooling channel 36 belongs to a multi-threaded water channel (that is, the sixth cooling channel 36 has multiple water channels connecting the third liquid inlet 23a and the third liquid outlet 23b); in order to eliminate the problem of cooling water reflux, a guide member may be provided at the connection between the sixth cooling channel 36 and the third liquid inlet 23a, so as to utilize the guide member to eliminate the problem of flow velocity unevenness caused by cooling water reflux.

[0086] It is worth mentioning that when the sixth cooling channel 36 is a closed ring structure, it can be a single-ring structure or a double-ring structure, and there is no limitation on this, and the user can determine it according to the actual situation.

[0087] In an alternative embodiment, if Figure 1 , Figure 3 , Fig.13 and Fig.15 As shown, a focusing slot body 24 is formed at one end of the end cover 23 close to the coupling member 1, and a feedthrough hole 241 and a seventh cooling channel 37 are provided at one end of the focusing slot body 24 away from the end cover 23; the feedthrough hole 241 is coaxially arranged with the first beam hole 1211, and the seventh cooling channel 37 is an annular structure coaxially arranged with the focusing slot body 24; a fourth liquid inlet 24a and a fourth liquid outlet 24b connected to the seventh cooling channel 37 are provided on the inner surface of the end of the focusing slot body 24 away from the end cover 23.

[0088] It should be noted that the radius of the seventh cooling channel 37 can be determined according to actual conditions and is not limited thereto. In this embodiment, the radius of the seventh cooling channel 37 is 6 mm.

[0089] like Fig.15As shown, the seventh cooling channel 37 is an open ring structure as a whole, and the fourth liquid inlet 24a and the fourth liquid outlet 24b are respectively arranged at the two ends of the seventh cooling channel 37; at this time, the seventh cooling channel 37 belongs to a single-thread water channel (that is, there is only one water channel connecting the fourth liquid inlet 24a and the fourth liquid outlet 24b in the seventh cooling channel 37).

[0090] It should be noted that the distance between the two ends of the seventh cooling channel 37 can be determined according to actual conditions and is not limited thereto. In this embodiment, the distance between the two ends of the seventh cooling channel 37 is 40 mm.

[0091] Of course, in other embodiments, the seventh cooling channel 37 may also be a closed ring structure, and the fourth liquid inlet 24a and the fourth liquid outlet 24b are symmetrically arranged about the center of the seventh cooling channel 37; in this case, the seventh cooling channel 37 belongs to a double-threaded water channel (i.e., the seventh cooling channel 37 has two semi-circular water channels for connecting the fourth liquid inlet 24a and the fourth liquid outlet 24b). In order to prevent the cooling water in one half of the ring water channel from flowing back to the other half of the ring water channel, affecting the uniformity of the cooling water flow rate distribution and further affecting the convection heat transfer coefficient, a guide member may be provided at the connection between the seventh cooling channel 37 and the fourth liquid inlet 24a, so as to use the guide member to divide the cooling water flowing into the fourth liquid inlet 24a into two identical paths, so as to eliminate the cooling water reflux phenomenon.

[0092] In an alternative embodiment, if Figure 3 and Fig.16 As shown, a tuner 25 is arranged in the accelerator housing 21 to eliminate the deviation of the field distribution and the resonance frequency caused by the processing and assembly of the acceleration cavity; the tuner 25 is located at the position where the magnetic field intensity is the strongest, and the heating phenomenon is relatively serious; in order to suppress the temperature rise of the tuner 25, an eighth cooling channel 38 needs to be arranged on the tuner 25; the eighth cooling channel 38 is an annular structure arranged circumferentially around the tuner 25, and the tuner 25 is provided with a second liquid inlet channel 25a and a second liquid outlet channel 25b connected to the eighth cooling channel 38; wherein the second liquid inlet channel 25a and the second liquid outlet channel 25b both extend along the axial direction of the tuner 25.

[0093] It should be noted that the location of the eighth cooling channel 38 can be determined according to actual conditions and is not limited thereto. In this embodiment, the axial distance between the eighth cooling channel 38 and the free end of the tuner 25 (ie, the non-connected end of the tuner 25) is 10 mm.

[0094] It should be noted that the distance between the second liquid inlet channel 25a and the second liquid outlet channel 25b can be determined according to actual conditions and is not limited thereto. In this embodiment, the distance between the second liquid inlet channel 25a and the second liquid outlet channel 25b is 15 mm.

[0095] like Fig.16 As shown, the eighth cooling channel 38 is an open ring structure as a whole, and the second liquid inlet channel 25a and the second liquid outlet channel 25b are respectively arranged at the two ends of the eighth cooling channel 38; at this time, the eighth cooling channel 38 belongs to a single-thread water channel (that is, there is only one water channel in the eighth cooling channel 38 connecting the second liquid inlet channel 25a and the second liquid outlet channel 25b).

[0096] It should be noted that the distance between the two ends of the eighth cooling channel 38 can be determined according to actual conditions and is not limited thereto. In this embodiment, the distance between the two ends of the eighth cooling channel 38 is 40 mm.

[0097] Of course, in other embodiments, the eighth cooling channel 38 may also be a closed ring structure, and the second liquid inlet channel 25a and the second liquid outlet channel 25b are symmetrically arranged about the center of the eighth cooling channel 38; in this case, the eighth cooling channel 38 belongs to a double-threaded water channel (i.e., the eighth cooling channel 38 has two semi-circular water channel channels connecting the second liquid inlet channel 25a and the second liquid outlet channel 25b). In order to prevent the cooling water in one semi-circular water channel from flowing back to the other semi-circular water channel, affecting the uniformity of the cooling water flow rate distribution and further affecting the convective heat transfer coefficient, a guide member may be provided at the connection between the eighth cooling channel 38 and the second liquid inlet channel 25a, so as to use the guide member to divide the cooling water flowing into the second liquid inlet channel 25a into two identical paths, so as to eliminate the cooling water reflux phenomenon.

[0098] Since the accelerating cavity will expand and deform when heated, in order to limit the deformation of the accelerating cavity, such as Figure 1 and Figure 3 As shown, a support seat 4 may be disposed under each accelerator housing 21 ; in the axial direction, the support seat 4 is located between the end cover 23 and the drift tube 22 disposed adjacent to the end cover 23 .

[0099] When the coupled linear accelerator is in operation, the external cooling medium circulation device flows low-temperature cooling water into the corresponding cooling channel through each liquid inlet or each liquid inlet channel, and exchanges heat with the components in the cooling channel during the flow process to be converted into high-temperature cooling water. Then, the high-temperature cooling water is discharged back to the external cooling medium circulation device through the corresponding liquid outlet or liquid outlet channel for cooling. The cooled cooling medium enters each cooling channel again to achieve circulating cooling of the coupled linear accelerator. The external cooling medium circulation device can adopt water cooling, oil cooling and phase change medium cooling circulation devices in the prior art, and the way it is connected to the cooling channel of the coupling 1 and the accelerator 2 can adopt various known channel connection methods such as existing threaded connection, bayonet connection, welding, etc.

[0100] Due to the different power losses of various components in the coupled linear accelerator, the heating phenomenon of each component is also different. In order to verify the effectiveness and rationality of the above cooling system, a multi-physics coupling analysis and calculation of the coupled linear accelerator with a cooling system was performed at an ambient temperature of 20°C, and the following results were obtained:

[0101] like Fig.21 and Fig. 22 As shown, the maximum heat generation is located at the connection between the accelerator housing 21 and the tuner 25, and the temperature rise at the maximum heat generation is 4.64°C (the difference between the maximum temperature 24.64°C and the ambient temperature 20°C). Fig.23 As shown, the maximum deformation is located at the drift tube 22, and the maximum deformation is 24.5 μm. The deformation of the entire accelerating cavity is small, and the maximum deformation of the cavity does not exceed 15 μm, which effectively reduces the resonant frequency deviation caused by the change in cavity size. Fig.24 As shown, the maximum thermal stress is located at the connection between the drift tube body 221 and the corresponding second support rod 222, and the maximum thermal stress is 14.4MPa, which is at a relatively low level, ensuring the support stability of the drift tube body 221. The thermal stress of the accelerating cavity and the end cover 23 are relatively low, and the impact on the normal operation of the accelerating cavity is very small and can be ignored. The frequency drift of the accelerating cavity in the working state is -10.62kHz, which basically has no impact on beam transmission.

[0102] When the RF power increases, the power consumption (i.e., power loss) of the accelerator is bound to increase; when performing multi-physics coupling analysis and calculation, the influence of the accelerator power consumption on multi-physics parameters can be explored by adjusting the input RF power. Fig.25 As shown, the maximum temperature, maximum deformation, maximum thermal stress and frequency drift of the accelerator are positively correlated with the power consumption of the accelerator. Therefore, when the input power increases, the maximum temperature, maximum deformation, maximum thermal stress and frequency drift of the accelerator will increase linearly. It is found through analysis that when the input power increases by 20%, the power consumption of the accelerator is 48.36KW, the maximum temperature of the accelerator increases by 8.31℃, the maximum deformation is 29.7μm, and the frequency deviation is -15.51kHz. At this time, the transmission efficiency of the accelerator is still maintained above 99%. Therefore, these changes are within an acceptable range and have little effect on the performance of the accelerator. It can be seen that the cooling system of the present application can ensure a good cooling effect even when the power exceeds the design value by 20%, ensuring the rationality and effectiveness of the cooling system.

[0103] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0104] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A cooling system for a coupled linear accelerator, comprising a coupling member (1) and two accelerators (2), wherein the coupling member (1) couples the two accelerators (2) to form a coupled linear accelerator; characterized in that: The coupling member (1) and the accelerator (2) are both provided with cooling channels for the flow of cooling medium, and the cooling channels are connected to an external cooling medium conveying device; the coupling member (1) comprises a coupling shell (11), and a first cooling channel (31) is provided on the shell wall of the coupling shell (11); the first cooling channel (31) is an annular structure arranged around the coupling shell (11), and a first liquid inlet (11a) and a first liquid outlet (11b) which are connected to the first cooling channel (31) are provided on the outer surface of the coupling shell (11); the accelerator (2) comprises an accelerator shell (21), and a plurality of third cooling channels (33) are provided in the shell wall of the accelerator shell (21); the third cooling channels (33) extend along the axial direction of the accelerator shell (21), and a second liquid inlet (21a) and a second liquid outlet (21b) are provided at two ends of the third cooling channel (33), respectively.

2. The cooling system according to claim 1, characterized in that: A magnet drift tube (12) is arranged in the coupling member (1); the magnet drift tube (12) comprises a magnet drift tube body (121) and a first support rod (122); the magnet drift tube body (121) is installed in the coupling housing (11) via the first support rod (122); a second cooling channel (32) is arranged on the tube wall of the magnet drift tube body (121); the second cooling channel (32) is an open annular structure circumferentially arranged around the magnet drift tube body (121); and a first liquid inlet channel (1221) and a first liquid outlet channel (1222) are respectively arranged at two ends of the second cooling channel (32); the first liquid inlet channel (1221) and the first liquid outlet channel (1222) are located in the first support rod (122).

3. The cooling system according to claim 1, characterized in that: The accelerator (2) is provided with a plurality of drift tubes (22); the drift tubes (22) comprise a drift tube body (221) and two second support rods (222) symmetrically arranged on the drift tube body (221); the drift tube body (221) is installed in the accelerator (2) via the second support rods (222); a fourth cooling channel (34) is provided on the tube wall of the drift tube body (221), and the fourth cooling channel (34) is a closed annular structure circumferentially arranged around the drift tube body (221); a fifth cooling channel (35) is provided in the second support rod (222) and is connected to the fourth cooling channel (34), and the fifth cooling channel (35) extends along the second support rod (222) to the outside of the accelerator (2); one of the two fifth cooling channels (35) is a liquid inlet channel, and the other is a liquid outlet channel.

4. The cooling system according to claim 3, characterized in that: A flow guide (223) is provided at the connection point between the fourth cooling channel (34) and the liquid inlet channel; the flow guide (223) is located on the inner wall of the fourth cooling channel (34).

5. The cooling system according to claim 1, characterized in that: An end cover (23) is provided at one end of the accelerator (2) away from the coupling member (1), and a sixth cooling channel (36) is provided in the end cover (23); the sixth cooling channel (36) is an annular structure coaxially arranged with the end cover (23), and a third liquid inlet (23a) and a third liquid outlet (23b) in communication with the sixth cooling channel (36) are provided on an end surface of the end cover (23) away from the coupling member (1).

6. The cooling system according to claim 5, characterized in that The sixth cooling channel (36) comprises an inner ring channel (361) having an opening and two outer semi-ring channels (362); the two ends of the inner ring channel (361) are respectively connected to the two outer semi-ring channels (362), and the free ends of the two outer semi-ring channels (362) are respectively connected to the third liquid inlet (23a) and the third liquid outlet (23b).

7. The cooling system according to claim 5, characterized in that: A bunching slot body (24) is formed at one end of the end cover (23) close to the coupling member (1), and a seventh cooling channel (37) is provided at one end of the bunching slot body (24) away from the end cover (23); the seventh cooling channel (37) is an annular structure coaxially arranged with the bunching slot body (24), and a fourth liquid inlet (24a) and a fourth liquid outlet (24b) in communication with the seventh cooling channel (37) are provided on the inner surface of one end of the bunching slot body (24) away from the end cover (23).

8. The cooling system according to claim 1, characterized in that: The accelerator (2) is provided with a tuner (25), and the tuner (25) is provided with an eighth cooling channel (38); the eighth cooling channel (38) is an annular structure circumferentially arranged around the tuner (25), and the tuner (25) is provided with a second liquid inlet channel (25a) and a second liquid outlet channel (25b) which are in communication with the eighth cooling channel (38); the second liquid inlet channel (25a) and the second liquid outlet channel (25b) extend along the axial direction of the tuner (25).

9. The cooling system according to claim 1, characterized in that: The shortest distance between an end of the accelerator housing (21) close to the coupling member (1) and the third cooling channel (33) on the accelerator housing (21) is 50 mm, and the shortest distance between an end of the accelerator housing (21) far from the coupling member (1) and the third cooling channel (33) on the accelerator housing (21) is 50 mm.

10. The cooling system according to claim 1, characterized in that The first cooling channel (31) is an open annular structure, and the distance between the two ends of the first cooling channel (31) is 40 mm.

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