Klystron device and waveguide isolation window for linear accelerator

Abstract

The utility model discloses a klystron device and a waveguide isolation window for a linear accelerator, the klystron device comprises a collector, an output cavity, a resonant cavity, an electron gun and a high-voltage contact, the klystron device also comprises a waveguide device and a waveguide isolation window, the waveguide device comprises a first waveguide tube and a second waveguide tube, the first waveguide tube is connected with the output cavity, and the second waveguide tube is connected with an accelerating tube of a linear accelerator; the waveguide isolation window comprises a waveguide input tube, a waveguide output tube, an isolation window main body and two sealing flanges, the first waveguide tube is connected with the waveguide input tube through the first sealing flange, and the second waveguide tube is connected with the waveguide output tube through the second sealing flange. According to the klystron, the working state stability of the klystron can be improved, and the production cost can be reduced.

Description

Technical Field

[0001] The utility model relates to a klystron device and a waveguide isolation window for a linear accelerator. Background Art

[0002] A linear accelerator usually refers to an accelerator that uses a high-frequency electromagnetic field to accelerate particles, and the trajectory of the accelerated particles is a straight line. A high-frequency linear accelerator (HLA) is a device that accelerates charged particles using a high-frequency electric field distributed along a straight track.

[0003] The accelerating cavity in a high-frequency linear accelerator usually uses radio frequency acceleration technology, that is, using a high-frequency electric field to accelerate charged particles. By introducing a high-frequency electric field in the accelerating cavity, the particles can obtain higher energy and speed. High-frequency linear accelerators usually have higher acceleration capabilities and efficiency, so they have advantages in generating high-energy particle beams.

[0004] In the medical field, high-frequency linear accelerators are widely used in radiotherapy to treat cancer and tumors. By generating high-energy electron or photon beams, this accelerator can precisely target tumor cells and deliver high-energy particle beams into the patient's body to destroy malignant cells.

[0005] In the field of industrial production and processing, industrial linear accelerators can play a role in disinfecting and sterilizing products.

[0006] For a linear electron accelerator, the space where electrons run must be a high vacuum environment (vacuum degree 10 -5 If the vacuum seal is not good for some reason and it is not discovered and dealt with in time, the whole vacuum system will be contaminated by foreign gases, which may seriously damage the electron gun. It will take several days or even weeks for the whole accelerator system to return to normal working condition, which will cause great losses to production.

[0007] Because the working environment of the waveguide isolation window itself is: vacuum inside and water jacket cooling outside, and the window ceramic piece of the waveguide window is generally a thin piece (about 3mm thick) made of aluminum oxide or beryllium oxide in order to achieve a high microwave transmission rate and isolate gases. Due to the presence of impurities in the raw materials of the ceramic piece and the manufacturing process, secondary electrons will be emitted when microwaves pass through (the electrons inside the klystron bombard the ceramic piece and further stimulate more electrons, forming a multiplication trend), causing breakdown damage to the window itself.

[0008] Therefore, the waveguide isolation window of the linear accelerator in the prior art is easily damaged, which causes the entire vacuum system to be contaminated by foreign gases, which is likely to cause significant losses. Utility Model Content

[0009] The technical problem to be solved by the utility model is to overcome the defect in the prior art that the waveguide isolation window of the linear accelerator is easily damaged, thereby causing the entire vacuum system to be contaminated by foreign gas and easily causing significant losses, and to provide a klystron device and waveguide isolation window for a linear accelerator that can improve the working stability of the klystron and reduce the production cost.

[0010] The utility model solves the above technical problems through the following technical solutions:

[0011] A klystron device for a linear accelerator, the klystron device comprising a collector, an output cavity, a resonant cavity, an electron gun and a high-voltage contact, wherein the klystron device further comprises a waveguide device and a waveguide isolation window,

[0012] The waveguide device comprises a first waveguide tube and a second waveguide tube, wherein the first waveguide tube is connected to the output cavity, and the second waveguide tube is connected to an accelerating tube of a linear accelerator;

[0013] The waveguide isolation window includes a waveguide input tube, a waveguide output tube, an isolation window body and two sealing flanges. The first waveguide tube is connected to the waveguide input tube by a first sealing flange, and the second waveguide tube is connected to the waveguide output tube by a second sealing flange.

[0014] Preferably, the sealing flange is a CPI ultra-high vacuum waveguide flange.

[0015] Preferably, the first sealing flange includes a front cover, a rear cover and a metal sealing ring, the front cover and the rear cover are both provided with a sealing ring mounting groove, at least two positioning pins are provided on one side of the sealing ring mounting groove, a flange blade is provided on the edge of the sealing ring mounting groove, the shape of the metal sealing ring matches the sealing ring mounting groove and is provided with a positioning hole that cooperates with the positioning pin, and the end face of the flange blade cuts into the metal sealing ring when the front cover and the rear cover are assembled.

[0016] Preferably, the second sealing flange includes a front cover, a rear cover and a metal sealing ring, the front cover and the rear cover are both provided with a sealing ring mounting groove, at least two positioning pins are provided in the sealing ring mounting groove, a flange cutting edge is provided at the edge of the sealing ring mounting groove, the shape of the metal sealing ring matches the sealing ring mounting groove and is provided with a positioning hole that cooperates with the positioning pin, and the end face of the flange cutting edge cuts into the metal sealing ring when the front cover and the rear cover are assembled, and the sealing flange is a square flange.

[0017] Preferably, the first sealing flange comprises a front cover, a rear cover and a sealing ring, the front cover is provided with a sealing ring installation groove, and the depth of the sealing ring installation groove is less than the thickness of the sealing ring.

[0018] Preferably, the sealing ring is a metal sealing ring, a flange edge is provided at the bottom of the sealing ring installation groove, a flange edge is provided at a position corresponding to the sealing ring installation groove on the rear cover, and the end face of the flange edge cuts into the metal sealing ring when the front cover and the rear cover are assembled.

[0019] Preferably, the waveguide isolation window also includes an isolation window body and a window ceramic piece, wherein the window ceramic piece is arranged inside the isolation window body, and the outer wall of the isolation window body is provided with a hollow water cooling cavity and the outer surface is provided with a cooling water inlet and outlet connected to the hollow water cooling cavity.

[0020] Preferably, a water cooling device is provided on the top of the collector, a sputtering ion pump is provided on the first waveguide tube, the collector is connected to the resonant cavity through an output cavity, and the electron gun and the high-voltage contact are provided in sequence below the resonant cavity.

[0021] The utility model also provides a waveguide isolation window for a linear accelerator, which is characterized in that the waveguide isolation window is used for the klystron device as described above.

[0022] The utility model also provides a linear accelerator, characterized in that the waveguide isolation window comprises the klystron device as described above.

[0023] On the basis of conforming to the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present utility model.

[0024] The positive and progressive effects of the utility model are:

[0025] The utility model can save manufacturing costs and eliminate the possibility of breakdown caused by secondary electrons in the waveguide isolation window, thereby improving the working stability of the klystron.

[0026] The utility model makes the conventional integrated sealed klystron into a detachable isolation window type klystron, so that the klystron can be applied in an integrated vacuum environment under the condition of saving one isolation window.

[0027] The benefits of reducing the isolation window: 1. Reducing component manufacturing costs; 2. Reducing the possibility of failure caused by the isolation window (secondary electron emission, or window breakdown caused by window impurity charge accumulation). BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of a klystron device in the prior art.

[0029] Figure 2 It is a structural schematic diagram of a klystron device in the prior art.

[0030] Figure 3 This is a schematic structural diagram of a klystron device according to Example 1 of the utility model.

[0031] Figure 4 This is another structural schematic diagram of the klystron device of Example 1 of the utility model.

[0032] Figure 5 This is a schematic structural diagram of the waveguide isolation window of Example 1 of the utility model.

[0033] Figure 6 This is a schematic structural diagram of the sealing flange of Example 1 of the utility model.

[0034] Figure 7 This is a schematic structural diagram of the sealing flange of Example 2 of the utility model.

[0035] Figure 8 This is another structural schematic diagram of the sealing flange of Example 2 of the utility model. DETAILED DESCRIPTION

[0036] The present invention is further described below by way of embodiments, but the present invention is not limited to the scope of the embodiments.

[0037] Example 1

[0038] In this embodiment, the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0039] See also Figures 3 to 6 , this embodiment provides an industrial linear accelerator, the linear accelerator comprising a klystron device.

[0040] The klystron device includes a collector 100 , an output cavity, a resonant cavity 101 , an electron gun 102 and a high-voltage contact 103 .

[0041] In particular, the klystron device further includes a waveguide device 104 and a waveguide isolation window 105 .

[0042] The waveguide device 104 includes a first waveguide tube 1041 and a second waveguide tube, wherein the first waveguide tube 1041 is connected to the output cavity, and the second waveguide tube is connected to the accelerating tube of the linear accelerator;

[0043] The waveguide isolation window 105 includes a waveguide input tube 1051 , a waveguide output tube 1052 , an isolation window body 1053 and two sealing flanges 1054 .

[0044] The first waveguide is connected to the waveguide input pipe by a first sealing flange. Figure 3 On the left side of the middle waveguide output tube, the second waveguide tube is connected to the acceleration tube of the linear accelerator) and is connected to the waveguide output tube by using a second sealing flange.

[0045] See also Figure 1 , Figure 2 The general working process of the klystron is as follows: a negative pulse high voltage (generally around 120 kV) is connected to the high-voltage contact at the bottom of the klystron, and the electron gun emits a pulsed electron beam under the negative high voltage and moves upward. Because the klystron is covered with a focusing coil on the outside, the electron beam is focused within the range of the central beam hole; the electron beam undergoes the interaction of several resonant cavities, and converts energy into microwaves at the top cavity (output cavity); it is then transmitted laterally along the first waveguide, passes through the isolation window, and continues to be transmitted along the second waveguide to the next link; the decelerated electrons eventually enter the collector, are consumed in the collector, converted into heat energy, and discharged by cooling water.

[0046] Because the klystron (a vacuum microwave device) must be evacuated and microwave aged before it is manufactured, an isolation window is required during in-factory testing and subsequent transportation.

[0047] The working environment of the waveguide isolation window itself is: vacuum inside and water jacket cooling outside. In order to achieve a high microwave transmission rate and isolate gases, the window ceramic piece of the waveguide window is generally a thin piece (about 3mm thick) made of aluminum oxide or beryllium oxide. Due to the presence of impurities in the raw materials of the ceramic piece and the manufacturing process, there is a certain probability that secondary electrons will be emitted when microwaves pass through (the electrons inside the klystron bombard the ceramic piece and further stimulate more electrons, forming a multiplication trend), causing breakdown damage to the window itself.

[0048] This embodiment proposes a new solution: the conventional welded isolation window of the klystron is changed to a vacuum flange connection mode; the window is operated during factory testing and transportation, but when used by customers, the flange is loosened, the waveguide window is removed, and the full vacuum waveguide is directly connected to form an integrated vacuum environment. While saving manufacturing costs, the possibility of breakdown caused by secondary electrons in the waveguide isolation window is reduced, and the working stability of the klystron is improved.

[0049] Specifically, the vacuum in the klystron is connected to the entire waveguide and even the accelerator to form an integrated vacuum. To this end, the isolation window of the klystron is designed to be detachable. After high-purity nitrogen is poured into the klystron, the isolation window is removed and the high vacuum flange (CPI method flange) of the klystron itself is used to connect with the corresponding waveguide, and then the vacuum is evacuated as a whole.

[0050] Wherein, the sealing flange is a CPI ultra-high vacuum waveguide flange.

[0051] CPI (Communication & Power Industries) is a supplier of electronic vacuum devices. CPI flange refers to an ultra-high vacuum waveguide flange (UHV Waveguide Flanges) launched by their company.

[0052] Compared with traditional flange connections, UHV Waveguide Flanges can provide sufficient sealing performance for waveguides with a smaller size, while also meeting excellent electrical conductivity for transmitting high-power electromagnetic waves, minimizing the risk of vacuum leakage and reducing equipment maintenance costs. They are widely used in the accelerator industry. As a type of UHV waveguide flange, CPI flanges are suitable for high vacuum and high temperature environments and are an efficient and reliable solution for waveguide connections.

[0053] The first sealing flange 1054 includes a front cover 10541 , a rear cover 10542 and a metal sealing ring 10543 .

[0054] The front cover and the rear cover are both provided with sealing ring installation grooves 10544.

[0055] At least two positioning pins 10545 are provided on one side of the sealing ring installation groove.

[0056] A flange cutting edge 10546 is provided at the edge of the sealing ring mounting groove.

[0057] The shape of the metal sealing ring matches the sealing ring installation groove and is provided with a positioning hole that cooperates with the positioning pin.

[0058] When the front cover and the rear cover are assembled, the end surface of the flange knife edge cuts into the metal sealing ring.

[0059] Use the flanges on both sides to squeeze the metal sealing ring in the middle. Because the flange has a special blade, the blade cuts into the sealing ring under greater pressure to achieve the purpose of sealing: In order to ensure the docking accuracy of the flanges on both sides, there are special locating pins to provide positioning.

[0060] Furthermore, in this embodiment, the first flange and the second flange both adopt the same structure.

[0061] The second sealing flange includes a front cover, a rear cover and a metal sealing ring. The front cover and the rear cover are both provided with a sealing ring mounting groove. At least two positioning pins are provided in the sealing ring mounting groove. A flange cutting edge is provided at the edge of the sealing ring mounting groove. The shape of the metal sealing ring matches the sealing ring mounting groove and is provided with a positioning hole that cooperates with the positioning pin. When the front cover and the rear cover are assembled, the end face of the flange cutting edge cuts into the metal sealing ring. The sealing flange is a square flange.

[0062] The waveguide isolation window 105 also includes an isolation window body 1053 and a window ceramic piece 1055, wherein the window ceramic piece is arranged inside the isolation window body, and the outer wall of the isolation window body is provided with a hollow water cooling cavity 1056, and the outer surface is provided with a cooling water inlet 1057 and a water outlet 1058 connected to the hollow water cooling cavity.

[0063] A water cooling device is arranged on the top of the collector, a sputtering ion pump is arranged on the first waveguide tube, the collector is connected to the resonant cavity through the output cavity, and the electron gun and the high-voltage contact are arranged in sequence below the resonant cavity.

[0064] Example 2

[0065] See also Figure 7 , Figure 8 This embodiment is basically the same as Embodiment 1, except that:

[0066] The first sealing flange includes a front cover 201, a rear cover 202 and a sealing ring 203. The front cover is provided with a sealing ring installation groove, and the depth of the sealing ring installation groove is less than the thickness of the sealing ring.

[0067] The sealing ring is a metal sealing ring, and a flange edge 204 is provided at the bottom of the sealing ring installation groove. A flange edge is provided at a position corresponding to the sealing ring installation groove on the rear cover. When the front cover and the rear cover are assembled, the end face of the flange edge cuts into the metal sealing ring.

[0068] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that these are only examples, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principle and essence of the present invention, but these changes and modifications fall within the protection scope of the present invention.

Claims

1. A klystron device for a linear accelerator, the klystron device comprising a collector, an output cavity, a resonant cavity, an electron gun and a high-voltage contact, characterized in that: The klystron device also includes a waveguide device and a waveguide isolation window. The waveguide device comprises a first waveguide tube and a second waveguide tube, wherein the first waveguide tube is connected to the output cavity, and the second waveguide tube is connected to an accelerating tube of a linear accelerator; The waveguide isolation window includes a waveguide input tube, a waveguide output tube, an isolation window body and two sealing flanges. The first waveguide tube is connected to the waveguide input tube by a first sealing flange, and the second waveguide tube is connected to the waveguide output tube by a second sealing flange.

2. The klystron device for a linear accelerator according to claim 1, characterized in that: The sealing flange is a CPI ultra-high vacuum waveguide flange.

3. The klystron device for a linear accelerator according to claim 1, characterized in that: The first sealing flange includes a front cover, a rear cover and a metal sealing ring. The front cover and the rear cover are both provided with a sealing ring mounting groove. At least two positioning pins are provided on one side of the sealing ring mounting groove. A flange blade is provided at the edge of the sealing ring mounting groove. The shape of the metal sealing ring matches the sealing ring mounting groove and is provided with a positioning hole that cooperates with the positioning pin. When the front cover and the rear cover are assembled, the end face of the flange blade cuts into the metal sealing ring.

4. The klystron device for a linear accelerator according to claim 3, characterized in that: The second sealing flange includes a front cover, a rear cover and a metal sealing ring. The front cover and the rear cover are both provided with a sealing ring mounting groove. At least two positioning pins are provided in the sealing ring mounting groove. A flange cutting edge is provided at the edge of the sealing ring mounting groove. The shape of the metal sealing ring matches the sealing ring mounting groove and is provided with a positioning hole that cooperates with the positioning pin. When the front cover and the rear cover are assembled, the end face of the flange cutting edge cuts into the metal sealing ring. The sealing flange is a square flange.

5. The klystron device for a linear accelerator according to claim 1, characterized in that: The first sealing flange comprises a front cover, a rear cover and a sealing ring. The front cover is provided with a sealing ring installation groove, and the depth of the sealing ring installation groove is less than the thickness of the sealing ring.

6. The klystron device for a linear accelerator according to claim 5, characterized in that: The sealing ring is a metal sealing ring, a flange edge is provided at the bottom of the sealing ring installation groove, a flange edge is provided at a position corresponding to the sealing ring installation groove on the rear cover, and the end face of the flange edge cuts into the metal sealing ring when the front cover and the rear cover are assembled.

7. The klystron device for a linear accelerator according to claim 1, characterized in that: The waveguide isolation window also includes an isolation window body and a window ceramic piece. The window ceramic piece is arranged inside the isolation window body. The outer wall of the isolation window body is provided with a hollow water cooling cavity and the outer surface is provided with a cooling water inlet and outlet connected to the hollow water cooling cavity.

8. The klystron device for a linear accelerator according to claim 1, characterized in that: A water cooling device is arranged on the top of the collector, a sputtering ion pump is arranged on the first waveguide tube, the collector is connected to the resonant cavity through the output cavity, and the electron gun and the high-voltage contact are arranged in sequence below the resonant cavity.

9. A waveguide isolation window for a linear accelerator, characterized in that: The waveguide isolation window is used for a klystron device, and comprises a waveguide input tube, a waveguide output tube, an isolation window body and two sealing flanges. The first waveguide tube is connected to the waveguide input tube by a first sealing flange, and the second waveguide tube is connected to the waveguide output tube by a second sealing flange.

10. A linear accelerator, characterized in that: The waveguide isolation window comprises a klystron device as claimed in any one of claims 1 to 8.

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