JP6401485B2 - Multi-cavity klystron - Google Patents

Description

  Embodiments of the present invention relate to a multi-cavity klystron.

  Conventionally, a multi-cavity klystron is an electron tube used to amplify a high-frequency signal, and an electron gun unit that emits an electron beam, a high-frequency signal input unit and output unit, a high-frequency interaction unit, and a used electron And a collector for capturing the beam. The high-frequency interaction unit is composed of a plurality of resonant cavities arranged in the traveling direction of the electron beam. The electron gun unit and the high-frequency interaction unit, the plurality of resonance cavities constituting the high-frequency interaction unit, and the high-frequency interaction unit and the collector unit are connected by drift tubes, respectively.

  In a multi-cavity klystron having such a configuration, an electron beam emitted from an electron gun section passes through a resonance cavity on the electron gun side having a signal input section and interacts with a plurality of resonance cavities in front of it. Acts and gathers. The kinetic energy of the gathered electron beam is applied to the input high frequency, and is extracted as a high frequency signal amplified to the target output from the output section provided in the collector-side resonance cavity.

  In general, in a multi-cavity klystron, in order to prevent a plurality of resonant cavities from being coupled at a high frequency, the diameter of the drift tube is reduced so that the cutoff frequency of the drift tube is higher than the operating frequency. However, even if the diameter of the drift tube is small and the diameter of the drift tube is the same, the drift tube itself becomes a resonance cavity, and unintentional oscillation with a frequency higher than the cutoff frequency of the drift tube may occur. . In this case, since a high frequency signal by oscillation is output, there is a problem that the output operation of the multi-cavity klystron becomes unstable.

Japanese Patent Laid-Open No. 10-340681

  The conventional multi-cavity klystron has an unstable output operation even if the drift tubes have the same diameter.

  The problem to be solved by the present invention is to provide a multi-cavity klystron capable of stabilizing the output operation.

Multi cavity klystron according to the present embodiment includes a plurality of resonant cavity, a plurality of drift tube, a table surface and a plurality of tubes containers. The plurality of drift tubes have the same diameter and connect the resonant cavities. In the surface portion, at least a part of the drift tube is made of a surface material having a higher high-frequency loss than the surface material of other portions of the drift tube. The plurality of tube containers constitute a drift tube. The surface portion is joined between the tube containers by brazing.

1 is a partial cross-sectional view of a multi-cavity klystron showing a first embodiment. It is sectional drawing which shows schematic structure of a multi-cavity klystron same as the above. It is a partial cross section figure of the multi-cavity klystron which shows 2nd Embodiment. FIG. 5 is a partial cross-sectional view of a multi-cavity klystron showing a third embodiment.

  Hereinafter, a first embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 2 is a cross-sectional view showing a schematic structure of the multi-cavity klystron 10. The multi-cavity klystron 10 includes an electron gun portion A. The electron gun section A includes a cathode 12a that generates an electron beam 11, an anode 12b that accelerates the electron beam 11, and the like.

  A high frequency interaction part B is provided in front of the electron gun part A with respect to the traveling direction of the electron beam 11. The high-frequency interaction unit B includes a cylindrical tube container 13 and, for example, five resonant cavities 14 a to 14 e formed in the tube container 13 and arranged in the traveling direction of the electron beam 11.

  A collector 15 that captures the electron beam 11 is provided in front of the high-frequency interaction part B.

  Among the plurality of resonant cavities 14a to 14e constituting the high frequency interaction part B, a high frequency signal input part 16, for example, a coaxial line is connected to the resonant cavity 14a located on the electron gun part A side. An output unit 17, such as a waveguide, is connected to the resonance cavity 14e located on the collector 15 side.

  A drift tube 18 having the same diameter is connected between the electron gun portion A and the high-frequency interaction portion B, between the plurality of resonance cavities 14a to 14e, and between the high-frequency interaction portion B and the collector 15.

  FIG. 1 is a cross-sectional view of a part of the multi-cavity klystron 10. The resonant cavity 14b and the resonant cavity 14c are connected by a drift tube 18.

  The tube container 13 constituting the drift tube 18 is made of, for example, copper.

  The drift tube 18 is provided with a surface portion 19 in which a part of the drift tube 18 is made of a surface material having a higher high-frequency loss than the surface material of other portions of the drift tube 18. The surface portion 19 is formed in a cylindrical shape, and is disposed in an annular groove 18a formed in the drift tube 18. The surface portion 19 is made of an electromagnetic wave absorber such as silicon carbide (SiC) or a metal having a higher high frequency loss than copper such as stainless steel.

  The surface portion 19 of the drift tube 18 is not limited to the drift tube 18 between the resonance cavity 14b and the resonance cavity 14c, and may exist between any resonance cavities 14a to 14e, and all the materials are used. It doesn't have to be the same.

  In the thus configured multi-cavity klystron 10, the electron beam 11 emitted from the electron gun section A passes through the resonance cavity 14a on the electron gun section A side having the signal input section 16 and in front of it. A plurality of resonance cavities 14b to 14e interact to gather together. The kinetic energy of the gathered electron beam 11 is applied to the input high frequency, and is extracted as a high frequency signal amplified to a target output from the output unit 17 provided in the resonance cavity 14e on the collector 15 side.

  By the way, the multi-cavity klystron 10 is intended to amplify a high-frequency signal using the interaction between the resonant cavities 14a to 14e and the electron beam 11, but the drift tube 18 itself becomes a resonant cavity, and the drift tube 18 Unintentional oscillation at a frequency higher than the cutoff frequency may occur. In this case, since a high-frequency signal due to oscillation is output, the output operation of the multi-cavity klystron 10 may become unstable.

  According to the multi-cavity klystron 10 of the first embodiment, the surface portion 19 is provided, which comprises at least a part of the drift tube 18 with a surface material having a higher high-frequency loss than the surface material of the other part of the drift tube 18. Therefore, the Q value of the drift pipe 18 can be reduced. Therefore, it is possible to prevent unintentional oscillation with a frequency higher than the cutoff frequency of the drift tube 18, and to prevent the output of a high-frequency signal due to this oscillation, so that the output operation of the multi-cavity klystron 10 can be prevented. Can be stabilized.

  Next, FIG. 3 shows a second embodiment. In addition, the same code | symbol is used about the same structure as 1st Embodiment, and the description of the structure and effect is abbreviate | omitted.

  The tube container 13 includes a tube container 13a and a tube container 13b divided at the position of the drift tube 18 between the resonant cavity 14b and the resonant cavity 14c. These tube containers 13a and 13b are made of, for example, copper.

  A groove 18a is formed between the joint surfaces of the tube containers 13a and 13b, and a surface portion 19 is disposed in the groove 18a. The surface portion 19 is made of a surface material having a higher high-frequency loss than a surface material of the tube containers 13a and 13b, which are other portions of the drift tube 18, in part of the drift tube 18. For example, the surface portion 19 is made of an electromagnetic wave absorber such as silicon carbide (SiC) or a metal having a higher high frequency loss than copper such as stainless steel.

  At least one of the tube containers 13a and 13b is provided with a groove portion 21 in which a brazing material 20 for brazing between the joint surfaces of the tube containers 13a and 13b is disposed. Further, at least one of the surface portion 19 and the tube containers 13a and 13b has a groove portion 23 in which a brazing material 22 for brazing between the joint surfaces of the surface portion 19 and the tube containers 13a and 13b is disposed. Is provided. Then, by melting the brazing materials 20 and 22 disposed in the grooves 21 and 23 at a high temperature, the joint surfaces of the tube containers 13a and 13b and the joint surfaces of the surface portion 19 and the tube containers 13a and 13b are mutually brazed. It is attached.

  In addition, as long as the groove parts 21 and 23 are the range provided in each joining surface, the position and the number may be arbitrary. Further, the groove portion 21 may be provided in either of the tube containers 13a and 13b. Similarly, the groove 23 may be provided in any of the surface portion 19, the tube container 13a, and the tube container 13b. Further, the shape of the surface portion 19 may be arbitrary as long as the tube containers 13a and 13b can be combined except for the cylindrical surface forming the drift tube 18. The shapes of the joint surfaces of the tube containers 13a and 13b may be arbitrary as long as they can be combined with each other.

  According to the multi-cavity klystron 10 of the second embodiment, the surface portion 19 is provided, which comprises at least a part of the drift tube 18 with a surface material having a higher high-frequency loss than the surface material of the other part of the drift tube 18. Therefore, the Q value of the drift pipe 18 can be reduced. Therefore, it is possible to prevent unintentional oscillation with a frequency higher than the cutoff frequency of the drift tube 18, and to prevent the output of a high-frequency signal due to this oscillation, so that the output operation of the multi-cavity klystron 10 can be prevented. Can be stabilized. In addition, since the surface portion 19 can be joined between the tube containers 13a and 13b by brazing, the surface portion 19 can be easily installed in the tube container 13.

  Next, FIG. 4 shows a third embodiment. In addition, the same code | symbol is used about the same structure as 1st Embodiment, and the description of the structure and effect is abbreviate | omitted.

  The tube container 13 constituting the drift tube 18 is made of, for example, copper. A surface portion 19 is provided in which part of the drift tube 18 is made of a surface material having a higher high-frequency loss than the surface material of other portions of the drift tube 18.

  The surface portion 19 is made of a material having a higher high-frequency loss than that of the material forming the tube container 13, such as a titanium nitride (TiN) film or nickel (Ni) plating.

  According to the multi-cavity klystron 10 of the third embodiment, the surface portion 19 is provided, which comprises at least a part of the drift tube 18 with a surface material having a higher high-frequency loss than the surface material of the other part of the drift tube 18. Therefore, the Q value of the drift pipe 18 can be reduced. Therefore, it is possible to prevent unintentional oscillation with a frequency higher than the cutoff frequency of the drift tube 18, and to prevent the output of a high-frequency signal due to this oscillation, so that the output operation of the multi-cavity klystron 10 can be prevented. Can be stabilized. In addition, the surface portion 19 can be easily formed on the drift tube 18 by being composed of a titanium nitride coating or nickel metal plating.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

10 Multi-cavity klystron
13a, 13b tube container
14a-14e resonant cavity
18 Drift tube
19 Surface

Claims (2)

A plurality of resonant cavities;
A plurality of drift tubes of the same diameter connecting the resonant cavities;
A surface portion comprising at least a part of the drift tube with a surface material having a higher high-frequency loss than a surface material of the other part of the drift tube ;
Comprising a plurality of tube containers constituting the drift tube ,
The surface region, the multi-cavity klystron, characterized in that that have been joined by brazing between the tube container. The multi-cavity klystron according to claim 1, wherein the surface portion is formed of a titanium nitride film or nickel metal plating.

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