JPH01283742A - Gyrotron - Google Patents

Abstract

PURPOSE:To make it possible to set specific sizes of clearances of separation parts of waveguides highly accurately in the phase of completion by setting the clearances to be separated electrically with a high accuracy with ceramics parts. CONSTITUTION:Waveguides 18a to 18c through which electron beams and electromagnetic waves pass are separated maintaining specific clearances in the width direction, and insulated electrically by ringform insulators 26. And the ring-form insulator 26 is covered with a metal layer 36 at the parts except the specific circumferential parts at the outer and the inner peripheral surfaces. As a result, the sizes of the separation parts 20 and 21 to be separated electrically can be set highly accurately with the ceramics insulators 26, the metal layers 36 formed on the surfaces of the insulators 26, and exposed parts of the insulators.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention relates to a gyrotron, and in particular to a gyrotron having a structure in which a waveguide wall is electrically divided into a plurality of parts along the tube axis. Regarding Tron.

(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.

A type of gyrotron consists of a cylindrical electron beam formed by a group of electrons in cyclotron motion, and an electromagnetic wave that interacts with this electron beam in a single resonant circuit such as a resonant cavity, and is accumulated in the resonant circuit. The gyro heptanodrone, which causes oscillation due to loss of energy in the electron beam due to the electromagnetic energy generated by the electromagnetic wave, the gyro klystron, which uses a similar electron beam and multiple resonant cavities to amplify electromagnetic waves, and the similar electron beam and transmission circuit. Examples include a gyro traveling wave tube that interacts with a traveling wave within the transmission circuit, and a backward wave gyrotron that combines with a backward wave within a transmission circuit.

The operating frequency of the gyrotron is approximately several tens of lz
to 100-odd Gtlz is common, and when converted to wavelength, it is about 2+nl11 to several mm. Therefore, compared to klystrons and traveling wave tubes, the wavelength is 2
It is three orders of magnitude shorter than FiTe, and extremely high dimensional accuracy is required for each part of the high frequency circuit of the gyrotron.

On the other hand, in order to set appropriate operating conditions for the gyrotron, it is necessary to configure the gyrotron to be configured so that the amount of electron beam can be measured independently in the high frequency circuit section including the resonant cavity, the collector section, and the output window section. For such purposes, for example,
As disclosed in Japanese Patent No. 0-701337, a structure is adopted in which the waveguide wall, which serves as a high frequency transmission circuit and an electron beam path, is electrically separated into a plurality of parts along the tube axis. Each waveguide separation section is electrically insulated with an insulator such as a ceramic ring, and the waveguide walls are separated with a very small gap. The gap in this separation part is designed to prevent the fundamental wave component from leaking outside.
The dimensions are set to 710 or less. As mentioned above, since the wavelength is approximately 2 mm, this gap is approximately 0.2 mm s
Or you need to set it lower.

(Problem to be Solved by the Invention) Since the gap between the waveguide separation parts is extremely narrow, the gap set before assembly may become smaller during the assembly and exhaust processes of the gyrotron. Due to changes in component dimensions due to thermal history or the like, or changes in the shape and dimensions of each joint, it may not be possible to obtain the predetermined dimensional accuracy of the gap between the waveguide separation sections.

It is an object of the present invention to solve the above-mentioned disadvantages and to provide a gyrotron having a structure in which the predetermined gap size of the waveguide separation part can be set with high precision at the completion stage.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a structure in which the waveguide walls through which electron beams and electromagnetic waves pass are separated with a predetermined gap in the axial direction and are electrically connected by a ring-shaped insulator. The insulated waveguide separation section is hermetically sealed to this ring-shaped insulator via a sealing ring, and this sealing ring is also hermetically bonded to the waveguide wall.

The ring-shaped insulator is a gyrotron in which a metal layer is coated on the outer circumferential surface and other portions of the inner circumferential surface except for a predetermined circumferential portion.

(Function) According to the present invention, the gap that must be electrically isolated can be set with high precision using ceramic parts, and the gap size does not change during manufacturing processes such as assembly and exhaust. . Therefore, a highly reliable gyrotron can be obtained.

(Example) Examples thereof will be described below with reference to the drawings.

Note that the same parts are represented by the same symbols. Figure 1 shows the overall structure. In the same figure, reference numeral 11 is an electron gun section that generates a hollow electron beam, I2 is a tapered electron beam introducing section that is arranged downstream of the electron beam and has a diameter that gradually becomes smaller, and 13 is a resonator that is continuously provided downstream of the electron gun section. A cavity section 14 is also provided continuously downstream thereof, and a tapered guide section whose diameter gradually increases, and 15 is a cylindrical collector section disposed downstream thereof, l.
17 is a waveguide coupling flange, 18a, 18b
, Igc are copper waveguide walls through which electron beams or high frequency waves are passed and transmitted, 19 is a solenoid of a magnetic field device, and 20 and 21 are waveguide division parts.

Therefore, the structure of the waveguide separating section 20 will be explained with reference to FIGS. 2 and 3. That is, as shown in FIG.
8a and 18b are ring-shaped insulators 26 along the tube axis.
electrically isolated and isolated. That is, on each waveguide wall 18a, 18b, a retaining ring-shaped flange 22, 23 having high mechanical strength, such as thick-walled stainless steel, is fixed to the outer periphery of the waveguide wall 18a, 18b by soldering in the vicinity of the separating portion. On one opposing surface of these flanges 22, 23,
Thin flanges 24, 25 for welding are integrally provided. A ring-shaped insulator 26 made of ceramic is interposed in the separation portion. This ring-shaped insulator 26
As is clear from FIG. 3, a metal layer 36 is coated on the outer circumferential surface and other portions of the inner circumferential surface except for a predetermined circumferential portion.

For example, approximately at the center of the inner peripheral surface of the insulator 26 in the axial direction,
For example, the metal layer 36 is coated except for a portion having a width g of approximately 1710 nm at the operating wavelength. Note that this insulator exposed portion g does not necessarily have to be near the center in the axial direction. Further, as the metal layer 3G, for example, a metallized layer and a copper plating layer deposited thereon are suitable.

Sealing rings 27 and 28 are hermetically soldered to the outer peripheries of both surfaces of the ring-shaped insulator 2B.

Each sealing ring 27.28 is attached to a sealing body 29.30, and its tip end is hermetically welded to each thin-walled flange 24.25 at welds B, B. Both retaining flanges 2
2.23 denotes a plurality of connecting bolts 31.31 provided across the outside of the sealing body 29.30.
. . and nuts 32, 32, . . . are mechanically connected to each other so that the mutual spacing can be adjusted.

An insulating washer 33 is fitted into one flange 23, thereby electrically insulating both flanges 22, 23. The waveguide walls 18a and 18b are provided with a sealing ring 27.
．． 28 and the ring-shaped insulator 2B constitute a vacuum container. Note that numerals 34 and 35 in the figure represent refrigerant passages, respectively.

In the above description, the waveguide separation section 20 has been described, but the waveguide separation section 21 has a similar configuration.

FIG. 4 shows another embodiment of the present invention, which provides the same effects as the above embodiment.

That is, in this example, a groove 37 is formed in a portion g of the inner peripheral surface of the ring-shaped insulator 26 that is not covered with the metal layer 38, and the metal layer 36 is formed on the inner peripheral surface excluding the groove 37. There is. Thereby, electrical insulation can be maintained reliably, and the electrical insulation dimension g can be maintained with high precision.

In the embodiment shown in FIG. 5, the metal layer 36a is extended to the vicinity of the opening in the groove 37, and the surface of the insulator 26 is exposed inside to provide electrical insulation. This prevents a portion of the electron beam from directly colliding with the exposed surface of the insulator 26, resulting in stable operation.

[Effects of the Invention] As explained above, according to the present invention, the dimensions that require electrical isolation of the waveguide separation section can be adjusted between the ceramic insulator, the metal layer formed on its surface, and the exposed insulator section. Since the settings can be made with high precision, a highly reliable gyrotron can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view showing a gyrotron according to an embodiment of the present invention, FIG. 2 is an enlarged vertical cross-sectional view of the main part thereof, and FIG.
The figure is a longitudinal cross-sectional view showing one embodiment of the ring-shaped insulator used in the present invention, and FIGS. 4 and 5 are longitudinal cross-sectional views of essential parts each showing other embodiments of the present invention. 18a s 18b, 18c --- waveguide wall, 2
0, 21...Waveguide separation part, 2G...Ring-shaped insulator, 3G...Metal layer, 37...Groove. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] A gyro in which a waveguide wall through which electron beams and electromagnetic waves pass maintains a predetermined gap in the axial direction and has a waveguide separation part electrically insulated by a ring-shaped insulator. The gyrotron is characterized in that the ring-shaped insulator is coated with a metal layer on the outer circumferential surface and other portions of the inner circumferential surface other than a predetermined circumferential portion.