Multi-beam klystron

Abstract

To provide a multibeam klystron provided with a collector part capable of coping with miniaturization and simplification of a cooling mechanism.SOLUTION: The multi-beam klystron 10 comprises an electron gun part 14 for generating a plurality of electron beams 12, a collector part 18 for capturing the electron beams 12, and a plurality of resonance cavities 21 arranged between the electron gun part 14 and the collector part 18. The collector part 18 has a collector body 30 and a plurality of collector holes 31 which are provided in the collector body 30 and individually capture the electron beams 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION An embodiment of the present invention relates to a multi-beam klystron. [Background technology]

[0002] Conventionally, a multi-beam klystron comprises an electron gun section that generates multiple electron beams, a collector section that captures the electron beams, and multiple cavity resonators arranged between the electron gun section and the collector section. The collector section converts the captured electrons into heat and releases it, so the collector section is cooled by a cooling mechanism.

[0003] Multi-beam klystrons are classified into two types: one that captures multiple electron beams with one collector, and one that has multiple collectors, each pairing an electron beam with a collector. In the case of a single collector, the electron beam traveling toward the center of the collector must travel a long distance to be captured by the inner wall of the collector, resulting in a long overall length. In the case of individual collectors, individual cooling mechanisms are required, making the system more complicated. Therefore, a collector configuration that can accommodate both compactness and a simplified cooling mechanism is desired. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-147027 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-106977 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide a multi-beam klystron having a collector section that can be made compact and can accommodate a simplified cooling mechanism. [Means for solving the problem]

[0006] The multi-beam klystron of this embodiment includes an electron gun section that generates multiple electron beams, a collector section that captures the electron beams, and multiple resonant cavities arranged between the electron gun section and the collector section. The collector section has a collector body and multiple collector holes that are provided in the collector body and capture the electron beams individually. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view of a multi-beam klystron showing a first embodiment. [Figure 2] FIG. 2 is a plan view of the multi-beam klystron. [Figure 3] FIG. 2 is a cross-sectional view of the collector and cooling mechanism of the multi-beam klystron. [Figure 4] 4(a) to 4(c) are side views showing examples of the heat dissipation structure of the collector section of the same. [Figure 5] FIG. 10 is a cross-sectional view of a collector part of a multi-beam klystron showing a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] The first embodiment will be described below with reference to FIGS.

[0009] 1 and 2 show a multi-beam klystron 10. The multi-beam klystron 10 comprises a klystron body 11 and a focusing magnetic field device (not shown) that is arranged around the klystron body 11 and focuses an electron beam 12 traveling within the klystron body 11. In Fig. 1, 13 denotes the central axis of the multi-beam klystron 10.

[0010] The klystron body 11 includes an electron gun section 14 that generates multiple electron beams 12 on a circumference of a predetermined radius from a central axis 13, a radio frequency interaction section 15 that amplifies radio frequency power through the interaction between the electron beams 12 and a radio frequency electric field, an input section 16 that inputs radio frequency power to the radio frequency interaction section 15, an output section 17 that outputs the amplified radio frequency power from the radio frequency interaction section 15, a collector section 18 that captures the electron beams 12 that have passed through the radio frequency interaction section 15, and a cooling mechanism 19 that cools the collector section 18.

[0011] The high-frequency interaction section 15 has a plurality of drift tubes 20, each arranged on a circumference of a predetermined radius from the central axis 13, through which the electron beams 12 pass, and a plurality of resonant cavities 21 connected to the drift tubes 20 along the direction of propagation of the electron beams 12. The resonant cavities 21 include an input cavity 22 to which the input section 16 is connected, a plurality of intermediate cavities 23, and an output cavity 24 to which the output section 17 is connected.

[0012] 1 to 4 also show the collector section 18. The collector section 18 is attached to a pole piece 26 on the collector side through which pass magnetic field lines generated by the focusing magnetic field device to focus the electron beam 12. The pole piece 26 is provided with a plurality of holes 27 on a circumference of a predetermined radius from the central axis 13 through which the electron beam 12 passes.

[0013] The collector section 18 has a collector body 30 , and a plurality of collector holes 31 , cooling holes 32 , and a heat dissipation structure 33 provided in the collector body 30 .

[0014] The collector body 30 is made of a material such as copper, stainless steel, or nickel and has a solid cylindrical shape, i.e., is integrally formed as a single member. A first axial surface 30a of the collector body 30 is joined to the pole piece 26 by brazing or the like.

[0015] The multiple collector holes 31 are each provided on a circumference of a predetermined radius from the central axis 13 of the collector body 30. One axial end of each collector hole 31 is open to the first surface 30a of the collector body 30 and communicates with the hole 27 of the pole piece 26 and the drift tube 20, and the other axial end is closed. Each collector hole 31 is arranged coaxially with each drift tube 20 and each electron beam generating section (cathode) of the electron gun section 14. Each collector hole 31 individually captures the electron beam 12 passing through each drift tube 20, and converts the energy of the captured electron beam 12 into heat that is absorbed by the collector body 30.

[0016] The cooling holes 32 are cylindrical and are provided inside the collector body 30, surrounded by the multiple collector holes 31, and are coaxial with the central axis 13 of the collector body 30. That is, the cooling holes 32 are provided at positions that are equidistant from the collector holes 31. One axial end of the cooling hole 32 is located inside the first surface 30a of the collector body 30 and is closed, and the other end is open to the second surface 30b of the collector body 30 opposite the first surface 30a.

[0017] The heat dissipation structure 33 increases the surface area of ​​the outer peripheral surface of the collector body 30 to improve the heat dissipation effect of the cooling mechanism 19. The heat dissipation structure 33 may be formed by providing continuous concave and convex portions alternately in the circumferential direction along the axial direction on the outer peripheral surface of the collector body 30 as shown in Fig. 4(a), by providing continuous concave and convex portions alternately in the axial direction on the outer peripheral surface of the collector body 30 as shown in Fig. 4(b), or by providing concave and convex portions in both the axial and circumferential directions on the outer peripheral surface of the collector body 30 as shown in Fig. 4(c). Any structure may be used for the heat dissipation structure 33 as long as it can increase the surface area of ​​the outer peripheral surface of the collector body 30.

[0018] 3 shows the cooling mechanism 19. The cooling mechanism 19 includes a cooling jacket 40 that liquid-tightly houses the entire collector portion 18 between the pole piece 26, a cooling water inlet portion 41 that supplies cooling water (coolant) into the cooling jacket 40, and a cooling water outlet portion 42 that takes out the cooling water that has absorbed the heat of the connector portion 18 from the cooling jacket 40.

[0019] The cooling jacket 40 has an outer frame 43 and an inner frame 44 disposed inside the outer frame 43. The outer frame 43 is cylindrically shaped with one end open and the other end closed. Note that FIG. 3 is a schematic diagram with some parts omitted; in reality, a flange is separately provided between the pole piece 26 and the collector 18 to connect the cooling jacket 40. The flange and one end of the outer frame 43 of the cooling jacket 40 are sealed with an O-ring and fixed by screws or the like. The inner frame 44, like the outer frame 43, is cylindrically shaped with one end open and the other end closed, but its one end is spaced apart from the pole piece 26. The inner frame 44 is disposed with a gap between the inner surface of the outer frame 43 and the surface of the collector 18, and a flow path 45 through which cooling water flows is formed between the outer frame 43, the inner frame 44, and the collector 18.

[0020] Cooling water inlet section 41 has a cylindrical cooling water introduction section 46 that is disposed on central axis 13 and passes through the end faces of outer frame section 43 and inner frame section 44 and is joined to each other mainly by welding or the like. The tip side of cooling water introduction section 46 that protrudes into inner frame section 44 is inserted into cooling hole 32 of collector section 18. The tip side of cooling water introduction section 46 is disposed with a gap between it and the closed end face of cooling hole 32, and is also disposed with a gap between the outer peripheral surface of cooling water introduction section 46 and the inner peripheral surface of cooling hole 32.

[0021] The cooling water outlet portion 42 is formed in a cylindrical shape and is joined to the axial end face of the outer frame portion 43 mainly by welding or the like, and is connected to the gap between the outer frame portion 43 and the inner frame portion 44.

[0022] A flow path 45 is formed through which the cooling water supplied from the cooling water inlet 41 passes through the cooling water introduction section 46, between the cooling water introduction section 46 and the cooling holes 32 of the collector body 30, between the second surface 30b and outer peripheral surface of the collector body 30 and the inner frame section 44, and between the outer frame section 43 and the inner frame section 44, leading to the cooling water outlet 42.

[0023] In the multi-beam klystron 10, the electron gun section 14 generates multiple electron beams 12, the high-frequency interaction section 15 amplifies the high-frequency power input from the input section 16 through the interaction between the electron beams 12 from the electron gun section 14 and the high-frequency electric field generated by the focusing magnetic field device, and the high-frequency power amplified by the high-frequency interaction section 15 is output from the output section 17. The electron beams 12 that pass through the high-frequency interaction section 15 are captured by the collector section 18. In the collector section 18, the electron beams 12 passing through each drift tube 20 are individually captured by each collector hole 31, and the energy of the captured electron beams 12 is converted into heat and absorbed by the collector body 30. The collector section 18 is cooled by circulating cooling water using a cooling mechanism 19. At this time, the outer circumferential surface of the collector section 18 is provided with a heat dissipation structure 33, which increases the surface area, thereby improving the heat exchange efficiency with the cooling water and suppressing the temperature rise of the connector section 18.

[0024] Generally, multi-beam klystrons are classified into two types: one in which a collector section with a single collector hole captures multiple electron beams, and one in which multiple collector sections are provided, each pairing an electron beam with a collector section. In the case of a collector structure in which a collector section with a single collector hole captures multiple electron beams, the collector section becomes large in both the axial and radial directions. Furthermore, in the case of a collector structure in which multiple collector sections are provided, each pairing an electron beam with a collector section, providing a cooling mechanism for each collector section results in a complex design. Furthermore, the collector sections are often too close to each other, which can cause interference and make it impossible to install the cooling mechanism. If the diameter of the collector hole is narrowed to solve this problem, the electron beams may be reflected and returned to the output section, potentially destabilizing the operation of the multi-beam klystron.

[0025] In contrast, the multi-beam klystron 10 of this embodiment uses an integrated collector section 18 in which a collector body 30 made of a single member is provided with multiple collector holes 31 that individually capture the electron beams 12. This allows the collector section 18 to be made smaller in both the axial and radial directions, and furthermore, since it is only necessary to provide a cooling mechanism 19 corresponding to one collector section 18, the cooling mechanism 19 can be simplified.

[0026] In addition, the collector part 18 has cooling holes 32 provided inside the part surrounded by multiple collector holes 31, and the cooling mechanism 19 causes cooling water to flow into the cooling holes 32, so that areas of the collector part 18 where heat tends to accumulate can be effectively cooled and the temperature rise of the collector part 18 can be suppressed.

[0027] FIG. 5 shows a second embodiment, in which the collector body 30 of the collector section 18 is provided by joining, by brazing or the like, a plurality of collector parts 50 which are divided into a plurality of parts corresponding to the axial direction along the central axis 13 from the electron gun section 14 to the collector section 18.

[0028] Each collector part 50 is provided with a part of each collector hole 31 and cooling hole 32 in the axial direction, which is divided.

[0029] In this way, by dividing the collector body 30 into a plurality of collector parts 50 and integrating them, the collector holes 31 and the cooling holes 32 can be easily formed.

[0030] The collector part 18 does not need to have the cooling holes 32 in the collector body 30, and even in this case, the collector part 18 can be cooled from the surface by the cooling mechanism 19. Furthermore, the cooling mechanism 19 may have any structure as long as it can cool the connector part 18.

[0031] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0032] 10 Multi-beam klystron 12 Electron Beam 14 Electron gun section 18 Collector section 19 Cooling mechanism 21 Resonant cavity 30 Collector body 31 Collector hole 32 Cooling hole 50 Collector parts

Claims

1. an electron gun unit that generates a plurality of electron beams; a collector portion that captures the electron beam; a plurality of resonant cavities disposed between the electron gun section and the collector section; Equipped with The collector section has a collector body and a plurality of collector holes provided in the collector body and configured to individually capture the electron beams. A multi-beam klystron characterized by:

2. The collector body is formed by a single member.

2. A multi-beam klystron according to claim 1.

3. The collector body is divided into a plurality of parts corresponding to the axial direction from the electron gun section to the collector section, and is provided by joining a plurality of collector parts, each of which is provided with a part of the collector hole in the axial direction.

2. A multi-beam klystron according to claim 1.

4. The collector portion has a cooling hole between the insides surrounded by the plurality of collector holes.

2. A multi-beam klystron according to claim 1.

5. A cooling mechanism is provided which covers the surface of the collector and circulates a cooling liquid between the surface of the collector and the surface of the collector.

5. A multi-beam klystron according to claim 1, wherein the multi-beam klystron is a laser beam.

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