Drift tube structure

Abstract

The utility model provides a drift tube structure which comprises a drift tube and two supporting rods symmetrically arranged on the outer surface of the drift tube. A first cooling pipeline for a cooling medium to flow is arranged on the pipe wall of the drift pipe, and the first cooling pipeline is of a closed annular structure arranged in the circumferential direction of the drift pipe; a second cooling pipeline communicated with the first cooling pipeline is arranged in the supporting rod, and the second cooling pipeline extends to the free end of the supporting rod along the supporting rod; one of the two second cooling pipelines is a liquid inlet pipeline, and the other second cooling pipeline is a liquid outlet pipeline; a flow guide part is arranged at the communication part of the first cooling pipeline and the liquid inlet pipeline, and is positioned on the inner wall of the first cooling pipeline; according to the drift tube structure, by arranging the flow guide part, the cooling medium at the liquid inlet of the first cooling pipeline is divided and guided, so that the problem of non-uniform flow velocity caused by backflow of the cooling medium is inhibited or eliminated, and the cooling effect of the drift tube structure is improved.

Description

Technical Field

[0001] This utility model relates to the field of accelerator technology, specifically to a drift tube structure. Background Technology

[0002] The Drift Tub Linac (DTL) accelerator is a common type of acceleration structure. It consists of multiple drift tubes arranged in a resonant cavity, with gaps between adjacent drift tubes. When the gap electric field is in an accelerating state, the particle beam passes through the accelerating gap and gains energy. When the gap electric field changes to a decelerating state over time, the particle beam enters the shielded area inside the drift tube without being decelerated.

[0003] Since the drift tube is the component closest to the particle beam and is a high-power component, it generates a lot of heat during operation. This heat not only affects the normal operation of the drift tube, but also causes the cavity to heat up and expand when the heat is transferred to the cavity, resulting in cavity frequency drift and thus affecting the operational stability of the DTL accelerator.

[0004] To prevent the drift tube from overheating and affecting the DTL accelerator's operating stabilizer, cooling is necessary. Utility model patent application number 201410357079.3 discloses a drift tube with a support rod and its manufacturing method, which includes a cooling water channel on the drift tube and a cooling water channel inside the support rod that communicates with the cooling water channel inside the drift tube. Because there are two support rods symmetrically arranged on the drift tube, when cooling water enters the drift tube through the cooling water channel of one support rod, it splits into two paths. One path flows along the semi-circular wall of one side of the drift tube, while the other path flows along the semi-circular wall of the other side, until the two paths converge and are discharged through the cooling water channel of the other support rod, completing the heat exchange between the drift tube and the support rod. In other words, the drift tube has two semi-circular water channels. However, in actual use, it has been found that the flow rates of the two cooling water paths differ. Sometimes, the cooling water from one semi-circular water path flows back towards the drift tube inlet along the other semi-circular water path, causing a deviation in the cooling water flow velocity within the drift tube and affecting the cooling effect. Utility Model Content

[0005] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a new drift tube structure to eliminate the problem of uneven flow rate caused by cooling water backflow, so as to improve the cooling effect of the drift tube structure.

[0006] To achieve the above objectives, this utility model provides a drift tube structure, including a drift tube and two support rods symmetrically arranged on the outer surface of the drift tube; the drift tube has a first cooling pipe on its wall for the flow of cooling medium, the first cooling pipe being a closed ring structure arranged around the circumference of the drift tube; the support rods have a second cooling pipe communicating with the first cooling pipe, the second cooling pipe extending along the support rods to the free end of the support rods; one of the two second cooling pipes is a liquid inlet pipe and the other is a liquid outlet pipe; a flow guide is provided at the connection between the first cooling pipe and the liquid inlet pipe, and the flow guide is located on the inner wall of the first cooling pipe.

[0007] Preferably, the guide element is symmetrically arranged about the centerline of the liquid inlet channel.

[0008] Preferably, the second cooling pipe is coaxially arranged with the support rod.

[0009] Preferably, the connection between the guide member and the inner wall of the second cooling pipe is smoothly transitioned.

[0010] Preferably, the length of the guide member in the direction of the drift tube axis is equal to the length of the first cooling pipe in the direction of the drift tube axis.

[0011] Preferably, the wall thickness between the first cooling pipe and the end of the drift pipe is 5 mm.

[0012] Preferably, the diameter of the first cooling pipe is 2.5 mm.

[0013] Preferably, the drift tube is shaped like a frustum or a cylinder.

[0014] Preferably, the support rod includes a frustum section, the small end of which is connected to the drift tube; the second cooling pipe includes a frustum section cooling pipe located within the frustum section, which is connected to the first cooling pipe.

[0015] Preferably, the support rod includes a cylindrical section connected to the large end of a frustum section, and the diameter of the cylindrical section is equal to the diameter of the large end of the frustum section; the second cooling pipe includes a cylindrical cooling pipe located within the cylindrical section, and the cylindrical cooling pipe is connected to the frustum cooling pipe.

[0016] As described above, the drift tube structure of this utility model has the following beneficial effects:

[0017] This application adds a guide component at the connection between the first cooling pipe and the liquid inlet channel, so that the cooling medium in the liquid inlet channel is smoothly separated into two parts that are as similar as possible when it flows into the first cooling pipe. These two parts of the cooling medium can flow along the semi-annular flow channels on both sides of the first cooling pipe, and finally converge at the connection between the first cooling pipe and the liquid outlet pipe before being discharged through the liquid outlet pipe. Since the flow velocity of the cooling medium flowing on both sides of the first cooling pipe is basically the same, when the two parts of the cooling medium converge and are discharged at the connection between the first cooling pipe and the liquid outlet pipe, it is not easy for one part of the cooling medium to enter the semi-annular flow channel where the other part of the cooling medium is located and flow back towards the liquid inlet channel along the semi-annular flow channel. This effectively improves the uniformity of the cooling medium flow velocity in the first cooling pipe, increases the convective heat transfer coefficient of the drift tube, and ensures the cooling effect of the drift tube. Attached Figure Description

[0018] Figure 1 This is a perspective view of the drift tube structure in this application.

[0019] Figure 2 This is a front view of the drift tube structure in this application.

[0020] Figure 3 for Figure 2 AA-direction cross-section.

[0021] Figure 4 for Figure 3 Enlarged view of point B.

[0022] Figure 5 A schematic diagram showing the flow guide installed on the drift tube.

[0023] Figure 6 This is a flow velocity distribution diagram of the cooling medium inside the drift tube structure before the flow guide is installed.

[0024] Figure 7 This is a diagram showing the distribution of convective heat transfer coefficients inside the drift tube structure before the installation of the flow guide.

[0025] Figure 8 This is a flow velocity distribution diagram of the cooling medium inside the drift tube structure after the flow guide is installed.

[0026] Figure 9 This is a diagram showing the distribution of convective heat transfer coefficients inside the drift tube structure after the flow guide is installed.

[0027] Explanation of reference numerals in the attached figures

[0028] Drift tube 1, beam hole 1, support rod 2, frustum section 2a, cylindrical section 2b, first cooling pipe 3, arc-shaped cooling channel 31, second cooling pipe 4, frustum section cooling pipe 41, cylindrical section cooling pipe 42, guide component 5. Detailed Implementation

[0029] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0030] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the disclosed technical content. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0031] This application provides a method such as Figure 1 The drift tube structure shown can be used in various accelerators containing drift tubes, such as DTL accelerators, IH-DTL accelerators, and CH-DTL accelerators.

[0032] like Figures 1 to 4 As shown, the drift tube structure involved in this application includes a drift tube 1 and two support rods 2 disposed on the outer surface of the drift tube 1, and both the drift tube 1 and the support rods 2 are centrally symmetrical structures; wherein, a flow-generating hole 11 is coaxially opened inside the drift tube 1, and a first cooling pipe 3 for the flow of cooling medium is provided on the tube wall of the drift tube 1; the first cooling pipe 3 is a closed ring structure arranged around the circumference of the drift tube 1; a second cooling pipe 4 is provided inside the support rod 2 and communicates with the first cooling pipe 3, and the second cooling pipe 4 extends along the axial direction of the support rod 2 to the free end of the support rod 2 to connect with an external cooling medium conveying device; at this time, one of the two second cooling pipes 4 is a liquid inlet pipe and the other is a liquid outlet pipe; for ease of description, the connection between the first cooling pipe 3 and the liquid inlet pipe is defined as the liquid inlet of the first cooling pipe 3, and the connection between the first cooling pipe 3 and the liquid outlet pipe is defined as the liquid outlet of the first cooling pipe 3.

[0033] It should be noted that the cooling medium includes, but is not limited to, various cooling fluids capable of heat exchange, such as cooling water, cooling oil, or phase change media. Based on cost considerations, the cooling medium in this embodiment is cooling water.

[0034] Depend on Figure 4 and Figure 5It is known that the first cooling pipe 3 is actually a parallel channel structure composed of two arc-shaped cooling channels 31. That is, when the cooling medium in the inlet channel reaches the inlet of the first cooling pipe 3, the cooling medium is divided into two parts, which flow along the two arc-shaped cooling channels 31 to the outlet of the first cooling pipe 3 and converge before being discharged from the drift tube structure along the outlet pipe, completing the heat exchange of the drift tube structure. However, in actual use, it was found that after the cooling medium in one arc-shaped cooling pipe 31 reaches the outlet of the first cooling pipe 3, it flows back along the other arc-shaped cooling pipe 31 towards the inlet of the first cooling pipe 3. This causes a decrease in the flow velocity of the cooling medium in the other arc-shaped cooling pipe 31, which not only leads to uneven flow velocity of the cooling medium in the drift tube structure, but also affects the flow efficiency of the cooling medium and the cooling effect.

[0035] To alleviate the problem of uneven flow rate caused by the backflow of cooling medium, such as Figure 4 As shown, this application provides a flow guide 5 at the connection between the first cooling pipe 3 and the liquid inlet pipe (i.e., at the liquid inlet of the first cooling pipe 3), and the flow guide 5 is located on the inner wall of the first cooling pipe 3; so as to use the flow guide 5 to divert and guide the cooling medium entering the liquid inlet of the first cooling pipe 3, and ensure that the flow rate of the cooling medium flowing out of each arc-shaped cooling channel 31 is as equal as possible, so as to avoid the problem of cooling medium backflow.

[0036] To ensure the installation stability of the drift tube structure, such as Figure 3 As shown, the two support rods 2 are symmetrically arranged about the drift tube 1, and the center lines of the support rods 2 intersect perpendicularly with the center line of the drift tube 1. Furthermore, to ensure the cooling effect of the support rods 2, the second cooling channel 4 is preferably coaxially arranged with the corresponding support rod 2. In this case, the lengths of the two arc-shaped cooling pipes 31 are equal in the circumferential direction; to ensure that the flow velocity of the cooling medium flowing out of each arc-shaped cooling channel 31 is equal, such as... Figure 4 As shown, the guide member 5 is symmetrical about the center line of the liquid inlet channel (i.e., the guide member 5 is symmetrical about the center line of the support rod 2). In this way, the guide member 5 can divide the cooling medium entering the liquid inlet of the first cooling pipe 3 into two identical parts and send them into the two arc-shaped cooling channels 31 respectively. Since the flow rate and velocity of the cooling medium flowing through the two arc-shaped cooling channels are consistent, the backflow phenomenon of the cooling medium is suppressed or eliminated, ensuring the uniformity of the flow velocity of the cooling medium in the drift tube 1, thereby ensuring the cooling effect.

[0037] Furthermore, such as Figure 4 and Figure 5As shown, the length of the guide 5 in the axial direction of the drift tube 1 is equal to the length of the first cooling pipe 3 in the axial direction of the drift tube 1 (i.e., the height of the guide 5 is equal to the height of the first cooling pipe 3), so as to ensure that the cooling medium at the liquid inlet of the first cooling pipe 3 can be divided into two identical parts, thereby eliminating the problem of uneven flow rate caused by the backflow of the cooling medium.

[0038] It should be noted that the flow guide 5 can be a plate-shaped structure or a block-shaped structure, and there is no limitation on this, as long as it can play the role of diverting and guiding the flow.

[0039] It is worth mentioning that when the flow guide 5 is a block structure, its outer surface is preferably set to a streamlined shape to achieve smooth flow guidance.

[0040] To reduce stress concentration, such as Figure 4 As shown, the connection between the guide 5 and the inner wall of the second cooling pipe 4 needs to be smooth.

[0041] It should be noted that the longer the guide element 5 is in the radial direction of the drift tube 1, the better the flow diversion effect. The specific length can be determined according to the actual situation; considering the difficulty of processing and setting, such as Figure 4 As shown, in this embodiment, the free end (i.e. the non-connecting end) of the guide member 5 is located in the area enclosed by the outer wall of the first cooling pipe 3. Thus, when processing the second cooling channel 4 inside the support rod 2, the guide member 5 will not be mistakenly processed.

[0042] In the above drift tube structure, the drift tube 1 is a cylindrical structure or a spherical frustum structure (i.e., the intermediate structure remaining after cutting a sphere or ellipsoid with two parallel equal diameter sections). There is no limitation on this. In this embodiment, the drift tube 1 is preferably a spherical frustum structure.

[0043] It should be noted that the diameter of the first cooling pipe 3 needs to be determined based on the outer diameter and inner diameter of the drift pipe 1 (i.e., the diameter of the beam hole 11). There is no limitation on this, as long as the structural strength of the drift pipe 1 is guaranteed. In this embodiment, the outer diameter of the drift pipe 1 is 40mm and the inner diameter is 25mm. At this time, the diameter of the first cooling pipe 3 is 2.5mm.

[0044] It should be noted that the height dimension of the first cooling pipe 3 (i.e., the length dimension in the axial direction of the drift pipe 1) needs to be determined according to the axial length of the drift pipe 1, and is not limited thereto; in this embodiment, the wall thickness between the end of the first cooling pipe 3 and the drift pipe 1 is 5mm to ensure the structural strength of the drift pipe 1.

[0045] In the above drift tube structure, the support rod 2 is a rotating body structure.

[0046] Specifically, such as Figure 2 and Figure 3 As shown, the support rod 2 includes a frustum section 2a, and the small end of the frustum section 2a is smoothly connected to the drift tube 1; the second cooling pipe 4 includes a frustum section cooling pipe 41 located in the frustum section 2a; the frustum section cooling pipe 41 is connected to the first cooling pipe 3, and the frustum section cooling pipe 41 changes shape within the frustum section 2a (that is, the frustum section cooling pipe 41 as a whole also has a frustum structure).

[0047] The design of the frustum-shaped support rod 2 not only allows for a smooth connection with the smaller drift tube 1, but also reduces stress concentration, ensuring the support stability of the support rod 2.

[0048] It should be noted that the size of the frustum section 2a is determined comprehensively based on the size of the drift tube 1 and the cavity size of the accelerator, and is not limited thereto. In this embodiment, the small end diameter of the frustum section 2a is 13mm and the large end diameter is 50mm. At this time, the large end diameter of the frustum section cooling pipe 41 is 17mm and the small end diameter is 6mm, so as to fit the first cooling pipe 3 inside the drift tube 1.

[0049] Furthermore, such as Figure 2 and Figure 3 As shown, the support rod 2 includes a cylindrical section 2b, which is connected to the large end of the frustum section 2a, and the diameter of the cylindrical section 2b is equal to the diameter of the large end of the frustum section 2a; the second cooling pipe 4 includes a cylindrical cooling pipe 42 located inside the cylindrical section 2b, and the cylindrical cooling pipe 42 is connected to the frustum cooling pipe 41; wherein, the diameter of the cylindrical section 2b is equal to the diameter of the large end of the frustum section 2a, and the diameter of the cylindrical cooling pipe 42 is equal to the diameter of the large end of the frustum cooling pipe 41.

[0050] The manufacturing method of the above-mentioned drift tube structure is as follows:

[0051] The blank is machined into a first intermediate part with a spherical structure and two support rods 4 using a lathe.

[0052] The spherical structure of the first intermediate part is machined to obtain a second intermediate part with a ball table structure and two support rods 4;

[0053] A beam hole 11 and an arc-shaped groove are machined on the ball table structure of the second intermediate component, and a guide 5 is formed between the two ends of the arc-shaped groove;

[0054] A second cooling channel 4, which communicates with the arc-shaped groove, is machined inside the support rod 4, and the opening of the arc-shaped groove is welded and sealed to form a first cooling channel 3.

[0055] Therefore, it can be seen that the setting of the guide element 5 does not increase the processing difficulty of the drift tube structure.

[0056] To verify the effect of the guide vane 5 on the flow velocity of the cooling medium and the convective heat transfer coefficient within the drift tube structure, a simulation analysis was conducted on the drift tube structure before and after the installation of the guide vane 5. Figure 4 , Figure 6 and Figure 8 It can be seen that after setting the flow guide 5, the maximum flow velocity in the outlet channel decreased, and the flow velocity in the reflux area increased, resulting in a more uniform flow velocity distribution in the drift tube structure. Figure 7 and Figure 9 It can be seen that the convective heat transfer coefficient is improved after the flow guide 5 is set, indicating that the cooling effect of the drift tube structure is improved after the flow guide 5 is set.

[0057] In summary, this utility model effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0058] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A drift tube structure, comprising a drift tube (1) and two support rods (2) symmetrically arranged on the outer surface of the drift tube (1); the drift tube (1) has a first cooling pipe (3) for the flow of cooling medium on its wall, the first cooling pipe (3) being a closed ring structure arranged circumferentially around the drift tube (1); the support rods (2) have a second cooling pipe (4) communicating with the first cooling pipe (3), the second cooling pipe (4) extending along the support rods (2) to the free end of the support rods (2); one of the two second cooling pipes (4) is an inlet pipe and the other is an outlet pipe; characterized in that, A guide (5) is provided at the connection between the first cooling pipe (3) and the liquid inlet pipe, and the guide (5) is located on the inner wall of the first cooling pipe (3).

2. The drift tube structure according to claim 1, characterized in that, The guide element (5) is symmetrically arranged about the center line of the liquid inlet channel.

3. The drift tube structure according to claim 1, characterized in that, The second cooling pipe (4) is coaxially arranged with the support rod (2).

4. The drift tube structure according to claim 1, characterized in that, The flow guide (5) and the inner wall of the second cooling pipe (4) are smoothly connected.

5. The drift tube structure according to any one of claims 1 to 4, characterized in that, The length of the guide (5) in the axial direction of the drift tube (1) is equal to the length of the first cooling pipe (3) in the axial direction of the drift tube (1).

6. The drift tube structure according to any one of claims 1 to 4, characterized in that, The wall thickness between the end of the first cooling pipe (3) and the drift pipe (1) is 5 mm.

7. The drift tube structure according to any one of claims 1 to 4, characterized in that, The diameter of the first cooling pipe (3) is 2.5 mm.

8. The drift tube structure according to claim 1, characterized in that, The drift tube (1) is generally shaped like a ping-pong ball or a cylinder.

9. The drift tube structure according to claim 1, characterized in that, The support rod (2) includes a frustum section (2a), the small end of which is connected to the drift tube (1); the second cooling pipe (4) includes a frustum section cooling pipe (41) located within the frustum section (2a), which is connected to the first cooling pipe (3).

10. The drift tube structure according to claim 9, characterized in that, The support rod (2) includes a cylindrical section (2b), which is connected to the large end of the frustum section (2a), and the diameter of the cylindrical section (2b) is equal to the diameter of the large end of the frustum section (2a); the second cooling pipe (4) includes a cylindrical cooling pipe (42) located inside the cylindrical section (2b), which is connected to the frustum cooling pipe (41).

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