JPH0265032A - Gytron - Google Patents

Abstract

PURPOSE:To make it possible to control so that the oscillation characteristic of a competing mode is suppressed and that the oscillation of a main mode is generated in a stabilized manner by changing reflection phase from a resonance cavity of a dielectric plate. CONSTITUTION:An axial direction slide section 10 is disposed in the vicinity of an output window which slide section is sealed airtightly with a diaphragm 7 capable of changing the position of a dielectric plate 1 in a tube axis direction. These components are connected and half-fixed with flanges 4, 6 and a distance adjustment rod 8. Even in the case the oscillation of a main mode is suppressed or the main mode oscillation is hard to occur, the reflection phase from the resonance cavity of a dielectric plate 1 is changed by controlling the position of the dielectric plate 1 in the tube axis direction. Thus the oscillation of the main mode is easily started in a stabilized manner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a gyrotron, and particularly to improvements in the vicinity of its output window.

(Prior Art) As is well known, a gyrotron is an electron tube whose operating principle is cyclotron maser action, and is being used as a high-frequency high-power source in the millimeter wave to submillimeter wave band.

This type of gyrotron has conventionally been constructed as shown in FIG. 3, in which reference numeral 21 is an electron gun section that generates a hollow electron beam. A tapered electron beam introducing section 22 whose diameter gradually becomes smaller is arranged downstream of the electron beam of the electron gun section 21, and a resonant cavity section 23 is continuously provided downstream of this electron beam introducing section 22. ing. Downstream of this resonant cavity 23, a tapered guide portion 24 whose diameter gradually increases
are provided continuously. A cylindrical collector section 25 is arranged downstream of this tapered guide section 24, and an output window section 26 having a dielectric plate 1 is arranged downstream of this collector section 25.

The output window section 26 is configured as shown in FIG. 4, and has a dielectric plate 1 provided within the circular waveguide 2. A circumferential coolant circulation path 9 is formed within the wall of the circular waveguide 2 in correspondence with the dielectric plate 1, and a pipe 12 leading to the coolant circulation path 9 is connected to the outer periphery of the circular waveguide 2. has been done. Water, which is a refrigerant, is flowed from this pipe] 2 into a refrigerant circulation path 9, so that the dielectric plate 1 is cooled.

Note that numerals 5 and 6 in FIG. 4 are flanges.

(Problem to be Solved by the Invention) In the conventional gyrotron as described above, the band of the output window portion 26 is determined by the thickness of the dielectric plate 1, and the thinner the dielectric plate 1, the wider the band. Become.

However, in order to obtain a high-frequency high-power output, the thickness of the dielectric plate 1 cannot be made sufficiently thin due to strength issues, and a sufficient band cannot be obtained, so reflection of competing modes becomes a problem. In particular, when the frequency becomes high, if the processing accuracy of the ceramic thickness of the dielectric plate 1 is not sufficient, there is a possibility that reflection of the main mode will also occur.

In such a case, oscillation in the competitive mode is likely to occur, and conversely, the required oscillation in the main mode may not occur.

This invention solves the following two problems, and aims to provide a gyrotron that can suppress the oscillation of the competitive mode and stably oscillate the main mode.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes an axial sliding portion hermetically sealed with a diaphragm that allows the position of the dielectric plate to be adjusted in the tube axis direction near the output window portion. The gyrotron is semi-fixed and connected by flanges and spacing adjustment rods.

(Function) According to the present invention, even when the main mode oscillation is suppressed or when the main mode oscillation is difficult to occur, the position of the dielectric plate in the tube axis direction is adjusted and the resonant cavity of the dielectric plate is By changing the reflection phase from the oscillation, main mode oscillation can be easily and stably caused.

(Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, since the gyrotron of the present invention has been improved around the output window, only the vicinity of the output window will be described. do.

That is, the vicinity of the output window in the present invention is configured as shown in FIG. Board 1
is provided. A circumferential coolant circulation path 9 is formed within the wall of the circular waveguide 2 in correspondence with the dielectric plate 1, and a pipe 12 leading to the coolant circulation path 9 is connected to the outer periphery of the circular waveguide 2. has been done. Water, which is a refrigerant, is flowed from one pipe 12 into the refrigerant circulation path 9 to cool the dielectric plate, and is then discharged from the other pipe 12.

Furthermore, a flange 4 is attached near the dielectric plate on the upstream side of the electron beam of the circular waveguide 2, that is, on the resonant cavity side, and the circular waveguide on the resonant cavity side (the collector section in FIG. A flange 6 is also attached to the end of the circular waveguide (25). Both ends of a diaphragm 7 are fixed to both flanges 4.6, and the diaphragm 7 connects the circular waveguide 2 at the output window and the circular waveguide 3 at the resonance cavity side.
They are vacuum-tightly connected and movable in the tube axis direction.

Also, a spacing adjustment rod 8 is attached to both flanges 4.6 with a nut 13.
14 and 15, and the spacing between the two circular waveguides 2.3, that is, the position of the dielectric plate 1, can be varied in the tube axis direction by means of the spacing adjustment rod 8.

As is clear from the figure, an annular step is formed at the end of the circular waveguide 3, and the circular waveguide 2 is formed along this annular step.
This end portion is movable, and this is an axial sliding portion 10, and this axial sliding portion 10 is hermetically sealed with a diaphragm 7. Now, in order to change the reflection phase from the resonant cavity part of the dielectric plate 1 (see Fig. 3), by adjusting the spacing adjustment rod 8, the circular waveguide 2 and the circular waveguide The wave tube 3 moves in the direction of the tube axis, changing the position of the dielectric plate 1, and as a result, the reflection phase seen from the resonant cavity can be changed. Thereby, adjustment can be easily made to cause main mode oscillation.

Since the gyrotron of the present invention has the same structure as the conventional example (FIG. 3) except for the vicinity of the output window, a detailed explanation of the overall structure will be omitted.

(Other Embodiments) In the above embodiment, when changing the reflection phase seen from the cavity resonator of the dielectric plate 1, the gap 11 is
occurs, and reflection mode conversion of the output electromagnetic wave may occur.

Therefore, in this other embodiment, in order to solve this problem, the circular waveguide 2 of the output window section which becomes the axial sliding section 10 is
and the circular waveguide 3 of the collector section, respectively, have a tapered section 2a.
and a tapered portion 3a are formed. According to this structure, even if the reflection phase from the resonant cavity of the dielectric plate 1 is changed and a gap 11 occurs, the waveguides 2.3 are smoothly connected via the tapered parts 2a, 3a, Mode conversion reflection of output electromagnetic waves becomes less likely to occur.

[Effects of the Invention] As explained above, according to the present invention, it is possible to change the reflection phase from the resonant cavity of the dielectric plate, thereby suppressing the oscillation characteristics of competing modes and stabilizing the oscillation of the main mode. It can be easily adjusted as desired.

Also, the output window is not aligned with the main mode,
Even when main mode oscillation is difficult to occur, stable main mode oscillation can be obtained by changing the reflection phase from the resonant cavity of the dielectric plate.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing the main part (output window section) of a gyrotron according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing another embodiment of the invention, and FIG. 3 is a conventional gyrotron. FIG. 4 is a vertical cross-sectional view showing the main part (output window part) of the conventional gyrotron. 1... Dielectric plate, 2.3... Circular waveguide, 4.5.
6... Flange, 7... Diaphragm, 8... Spacing adjustment rod, ]0... Axial direction slide part, 21... Electron gun part, 22... Tapered electron beam introducing part, 23...・
- Resonant cavity part, 24... Tapered guide part, 25...
Collector section, 26... output window section. Applicant's representative Patent attorney Takehiko Suzue Figure 1 ↓ Resonant cavity side diagram

Claims (1)

[Claims] An electron gun section, an electron beam introduction section that is continuously arranged downstream of the electron beam of the electron gun section, a resonant cavity section, a tapered guide section, a collector section, and the collector section. In the gyrotron, the gyrotron is equipped with an output window section that is provided downstream and has a dielectric plate that passes high frequency waves, and a diaphragm is provided near the output window section that allows the position of the dielectric plate to be adjusted in the tube axis direction. A gyrotron characterized in that a hermetically sealed axial sliding portion is provided, and these are connected and semi-fixed by a flange and a spacing adjustment rod.