JPH11149876A - Microwave tube - Google Patents

Abstract

(57) An object of the present invention is to provide a structure of a microwave tube capable of maintaining thermal damage of an airtight window of an output rectangular waveguide and a temperature rise of the output waveguide at a predetermined level. A microwave tube according to the present invention prevents electrons branched by an output cavity from directly colliding with a dielectric plate of a hermetic window provided at an end of an output rectangular waveguide. For this reason, barrier members 8a and 8b extending from the inner wall of the rectangular waveguide in parallel or perpendicular to the direction of the electric field are provided so that the airtight window cannot be directly seen through the drift tube. Barrier member 8
Refrigerant passages 9a and 9b that allow cooling by a cooling medium are formed at the distal end portions of the a and 8b, and the temperature rise is suppressed by injecting the cooling medium into the refrigerant passage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave tube such as a klystron, a linear accelerator, a gyrotron, or a traveling wave tube, and more particularly to an improvement in an output waveguide portion thereof.

[0002]

2. Description of the Related Art For example, a microwave tube such as a klystron has been developed which has a continuous output of several kilowatts or more and a pulse-like peak value of several megawatts or more.

When the output power becomes large as described above, if the airtight window of the output waveguide has a structure that can be seen from the drift tube side, reflected electrons or secondary electrons generated by colliding with the drift tube or the like are generated. The phenomenon of colliding with the dielectric hermetic window through the output waveguide increases. When the colliding electrons are accumulated near the hermetic window, cracks may occur in the dielectric of the hermetic window or the vacuum side and the atmospheric side of the dielectric of the hermetic window may be discharged because of the discharge from the accumulated electrons. It is known that dielectric breakdown occurs between the two.

[0004] From this, Japanese Patent Laid-Open No. Sho 51-126031
As shown in FIG. 3 to FIG.
There is an example in which a barrier plate that optically shields an electron beam passing through a drift tube and an airtight window is arranged in an output waveguide to protect the airtight window.

[0005]

However, by disposing a barrier plate as disclosed in Japanese Patent Laid-Open No. Sho 51-126031 in the output waveguide, the output of the electromagnetic wave passing through the output waveguide can be reduced. Is increased, the waveguide and the barrier plate are undesirably heated due to induced loss in the waveguide and the barrier plate, collision of stray electrons in the waveguide, and the like.

When the barrier plate is not provided, the inside of the waveguide is cooled by natural cooling by the air in contact with the outer wall of the waveguide or by forced cooling by adding a cooling device for cooling the waveguide from outside. Can be cooled to a predetermined level, but when a barrier plate is formed, the waveguide near the tip of the barrier plate and the leg of the barrier plate where the barrier plate and the waveguide are connected. When the temperature rises, the waveguide may be deformed.

For the above-mentioned reason, when the waveguide is deformed, there is a problem that the high-frequency output characteristics change and a desired output power cannot be obtained. Further, when the degree of temperature rise exceeds a predetermined level, there is a problem that the hermetic window and the dielectric of the hermetic window are damaged.

SUMMARY OF THE INVENTION An object of the present invention is to provide a structure of a microwave tube capable of maintaining a thermal damage to an airtight window of an output waveguide and a temperature rise of the output waveguide at a predetermined level.

[0009]

SUMMARY OF THE INVENTION The present invention has been made based on the above problems, and has an output rectangular waveguide between an electromagnetic wave passing hermetic window made of a dielectric plate and an output cavity. In the rectangular waveguide, conductive barrier members protruding partway from the waveguide wall parallel or perpendicular to the direction of the electric field of the transmitted microwave of the waveguide are spaced apart from each other by a predetermined distance, and are formed in the cavity. In a microwave tube projecting from each other so that a dielectric plate of the hermetic window cannot be directly seen through an electron beam passage, a first cooling medium passage is provided in the barrier member. Microwave tube.

In the microwave tube according to the present invention, a second cooling medium passage is formed on the outer wall of the rectangular waveguide so as to conduct heat, and the second cooling medium passage is formed in the barrier member. It is characterized by being connected to one cooling medium passage.
Further, the microwave tube according to the present invention is characterized in that the first cooling medium passage in the barrier member is formed near a tip of the barrier member.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram for explaining a klystron tube that compensates for amplification of oscillation output or attenuation of relay output by amplification among microwave tubes.

As shown in FIG. 1, the klystron tube 1 has a drift tube 2, an output cavity 4, and an output rectangular waveguide 3. The rectangular waveguide 3 has a circular airtight window 5 in which a dielectric plate 5a is fixed at a predetermined position at an end facing the output cavity.

The output rectangular waveguide 3 prevents electrons 7 passing through the drift tube gap G from reaching the hermetic window 5 between the connection portion 4a to the output cavity 4 and the hermetic window 5. In the waveguide 3, two screen-shaped first and second barrier members 8a and 8b are arranged at positions separated from each other in the longitudinal direction of the waveguide 3 from opposite wall surfaces. . That is, the first and second barrier members 8a and 8b are parallel or parallel to the direction of the electric field of the transmitted microwave of the waveguide 3 so that the dielectric plate 5a of the hermetic window 5 cannot be directly seen through the electron beam path. As shown in FIG. 2, the output waveguide 3 is formed on the vertical waveguide wall so as to extend beyond the central portion of the output waveguide 3 in the middle of the electron beam path.

The distal ends of the first and second barrier members 8a, 8b, ie, the barrier members 8a, 8b as shown in FIG.
In the first part, the barrier member 8a, 8b and a cooling medium for cooling the waveguide wall, for example, water, are guided to the portion farthest from the inner wall of the rectangular waveguide 3 in the cross-sectional direction of the waveguide 3. Cooling medium passage (hereinafter abbreviated as refrigerant passage) 9
a, 9b are formed.

On the outer periphery of the rectangular waveguide 3, there are provided second refrigerant passages 10a and 10b for cooling the waveguide wall. The refrigerant passages 9a, 9b, 1
Each of Oa and 10b is connected as one refrigerant passage by a connection part (not shown). That is, for example, the first refrigerant passages 9a and 9b are
Cooling water is supplied from a refrigerant supply device (not shown) via Oa. Similarly, the cooling water that has passed through the other first refrigerant passage 9b is returned to a not-shown refrigerant supply device via the second refrigerant passage 10b.

As described above, in the klystron tube described with reference to FIGS. 1 and 2, the output cavity 4 branches from the drift tube 2 into the output rectangular waveguide having a rectangular cross section. In order to prevent the electrons from directly colliding with the dielectric plate 5a of the hermetic window 5 provided at the end of the output waveguide, the inside of the waveguide is controlled so that the hermetic window 5 cannot be seen through the drift tube 2. Barrier members 8a, 8b extending from the wall in a direction parallel or perpendicular to the direction of the electric field are provided to protect the hermetic window 5. At the tip portions of the barrier members 8a and 8b,
Refrigerant passages 9a and 9b that enable cooling by a cooling medium are formed, and a rise in temperature is suppressed. This prevents the temperature of the barrier member from undesirably increasing due to dielectric loss or electron collision, thereby preventing the output waveguide from being deformed or causing damage to the hermetic window.

[0017]

As described above, according to the present invention, an undesired rise in the temperature of the output rectangular waveguide can be reduced.
This prevents the output waveguide from deforming and deteriorating the high-frequency output characteristics. Further, it is possible to prevent a structural defect such as damage to the airtight window from occurring.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a klystron tube according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along aa 'of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Klystron tube, 3 ... Output rectangular waveguide, 4 ... Output cavity, 5 ... Airtight window, 5a ... Dielectric plate, 7 ... Electron flow, 8a, 8b ... barrier member, 9a, 9b ... first refrigerant passage, 10a, 10b ... second refrigerant passage.

Continued on the front page (72) Inventor Koichiro Hirano 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki Power reactor and nuclear fuel development corporation Oarai engineering center

Claims (3)

[Claims] An output rectangular waveguide is provided between an electromagnetic wave passage hermetic window made of a dielectric plate and an output cavity, and an electric field direction of a microwave transmitted through the waveguide is provided in the rectangular waveguide. Conductor barrier members protruding halfway from the waveguide wall parallel or perpendicular to each other are spaced apart from each other at a predetermined interval, and the dielectric plate of the hermetic window cannot be directly seen through the electron beam passage in the cavity. A microwave tube protruding from each other, wherein the microwave tube has a first cooling medium passage in the barrier member. 2. A second cooling medium passage is formed on the outer wall of the rectangular waveguide so as to conduct heat, and the second cooling medium passage communicates with the first cooling medium passage in the barrier member. The microwave tube according to claim 1, wherein: 3. The microwave tube according to claim 1, wherein the first cooling medium passage in the barrier member is formed near a tip of the barrier member.