JPS6113532A - Gyrotron - Google Patents

Abstract

PURPOSE:To obtain a small gyrotron which can efficiently produce a great output by using a resonator which consists of a reflecting part which oscillates and amplifies electromagnetic waves radiated in diametrical directions by semi-optically reflecting them, and a resonator which has a long hole which can transmit electromagnetic waves. CONSTITUTION:The annular copper mirror 28 of a resonator 23 forms a resonant cavity. The doughnut-like inner surface of the mirror 28 facing an electron beam is a concave mirror (M1) which corresponds to a part of a spherical surface (P1). The mirror 28 reflects electromagnetic waves radiated in diametrical directions thereby oscillating and amplifying them. In order to partially transmit amplified electromagnetic waves 22, the mirror 28 is provided with a long slot 27 extending along the circumferential direction. An electomagnetic wave transmission mirror 29 is a semicircular copper ring. It transmits and focus straight polarized electromagnetic waves transmitted by the mirror 28 upon the target. The sectional shape of the mirror 29 is a part of an elliptic surface having a focus at the center (S). The focus of the mirror 29 coincides with an object to be heated such as plasma.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a gyrotron device that generates an electromagnetic beam for heating plasma in a nuclear fusion reactor.

[Prior art and its problems]

The conventional gyrotron device, as shown in FIG. , an output section 3 that resonates the electromagnetic waves obtained from this electron beam and outputs only electromagnetic waves.
It is mainly composed of.

The electron gun l includes a cathode 5 provided with an electron emission band 4, and this cathode 5.
four first anodes 6 coaxially arranged opposite to each other;
The anode 6 is configured to guide electrons extracted from the cathode 5 in two directions, and a second anode 7 generates a hollow electron beam 8.

Note that the electron gun 1 is provided with an insulator 9 for insulating between each electrode 5, 6.7, and a power source 10.1 for applying a voltage between each electrode, and the electron beam 8 is An electron gun coil 12 is arranged to shape the electron gun.

The output section 3 includes a resonance section 13 having the same potential as the second anode 7, an output matching section 14, a beam collector section 15, and an output waveguide section 16.
It mainly consists of a ceramic output window that is electrically isolated and allows only electromagnetic waves to pass through.

That is, the electron beam 8 led out from the electron gun 1 through the output section 31 is passed through the matching section 14 so that the electron beam generated by the magnetic coil 2 resonates at the resonance section 13 and becomes a predetermined electromagnetic wave.
The output window 17 matches the electromagnetic waves and outputs only electromagnetic waves to the waveguide section 16 through the output window 17. Resonant section 13 and matching section 1
The electron beam passing through the beam collector section 15 collides with the wall surface of the beam collector section 15 and is converted into heat. The heat at this time is cooled by a cooling device 18 provided on the wall of the output section 3 through which cooling water flows. Further, the interior of the electron gun 1 and the output section 3 is a vacuum I.

In conventional gyrotron devices configured in this way, the dimensions of the resonator cannot be made large due to the high frequency of the electronic resonance handled, and the large amount of Joule heat generated on the resonator wall results in a high output. It was difficult to make a device for this purpose. Therefore, a high-performance device that heats the plasma of a nuclear fusion device has drawbacks such as the necessity of arranging an extremely large number of devices. The purpose of this device is to provide a gyrotron device that transmits and focuses electromagnetic waves in a single direction so as to be suitable for plasma heating, and that can be configured efficiently and compactly to provide high output. do.

[Summary of the invention]

The present invention includes an electron gun that generates an electron beam, a magnetic field generator that applies a magnetic field to the electron beam emitted from the electron gun, and an electromagnetic wave generated when the electron beam passes through the magnetic field. A partially transmitting mirror body has a reflecting part that quasi-optically reflects electromagnetic waves radiated in a radial direction with respect to the traveling axis of the beam to resonate and amplify them, and a long hole-shaped transmitting part that can transmit the electromagnetic waves. This is a gyrotron device constructed by bending a resonator with JF11 in the i41+ direction of the electron beam.

〔Effect of the invention〕

According to the present invention, a co-transmitting part is formed using a part Rad transmission mirror having a long hole that semi-optically transmits electromagnetic waves partially, and a reflection part (IX) that bends the electromagnetic waves in the electron beam axis direction. As a result, electromagnetic waves can be extracted with a small aperture, and an output wave of 1u line polarization can be obtained. Furthermore, the entire structure can be made compact, and the intensity of the electromagnetic waves applied to the mirror can be reduced, reducing the Joule heat. It is possible to generate high-output electromagnetic waves.Furthermore, this high-output electromagnetic wave can be efficiently transmitted and focused in the target direction, so it can be used in specific locations such as plasma heating. It can also emit high-power electromagnetic waves.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail.

The gyrotron device according to the present invention is called a fluoro-optical gyrotron device because it handles electromagnetic waves optically, and as shown in FIG. Magnetic coils 218 to 2IC that apply a magnetic field to the emitted electron beam 19,'
Among the electromagnetic waves generated when the electron beam 19 passes through a magnetic field, the electromagnetic waves 22 radiated in the radial direction relative to the traveling axis of the electron beam 19 are shown in an enlarged view in FIG. A resonator 23 that resonates and amplifies quasi-optically, a transmission section 24 that transmits the electromagnetic waves 22 obtained by the resonator 23 in the output direction, and converts the energy of the used electron beam 19 into heat. It mainly consists of an electron beam dump 25. 26 is a magnetic coil for collecting the electron beam 19 on this dump 25. In addition, the magnetic coil 261
The co-photographing section 23 reflects some of the electromagnetic waves 22 radiated from the electron beam 19 in the radial direction due to resonance, and some of the electromagnetic waves 22 are reflected by the elongated holes (
It is composed of an annular partially transmitting mirror 28 which has the function of transmitting light to the outside through a slit 27.

The transmission unit 24 transmits the electromagnetic waves that have passed through the slit 27 of the partially transmitting mirror 28 into the radiation direction (Z direction) of the child beam 19.
Electromagnetic wave transmission mirror 2 to propagate while reflecting
It consists of 9.

This gyrotron device has an exhaust pipe 3 inside.
The exhaust from 0 creates vacuum dust, and the output end is a ceramic dI! so that it outputs only electromagnetic waves as before. ! (J) Output window] 7 is provided.1. ing. Also shown in the figure is a 4C electron beam dump 25ft: water cooling device i for td+ minutes heated by the electron beam! 'j is missing by 1.

The electron gun 20 generates an annular VL beam 19 by pressure from a conventional power source, and is preferably a magnetron type, but is not particularly limited.

The magnetic coils 21a to 2]c and 26 are composed of a plurality of coils so as to cover the electron gun 20, the partially transmitting mirror 28, and the electromagnetic wave transmission mirror 29, but they may also be composed of a single coil. However, it may be a superconducting coil, a normal conducting coil, or a permanent magnet as long as it can generate a predetermined magnetic field.

The mirror 28 of the resonant section 23 is a circular ring made of copper and forms a resonant cavity. When extracted and shown in FIGS. 2 and 3, the inner surface facing the electron beam has a donut shape all around the circumference. It is a concave mirror M1 whose focal point S is -H1t of the spherical surface P, and reflects the electromagnetic waves emitted in the radial direction rl to oscillate and amplify them. This mirror 28 is formed with a downhole slot 27 that opens along the circumferential direction in order to partially transmit the amplified electromagnetic wave 22.

In order for electromagnetic waves to pass through the opening of this slot 27, the length of the short side of the opening in the direction of the symmetry axis should be at least 1/2 of the wavelength of the resonant frequency, and the length of the good side of the opening is as follows. It is only necessary to set the value in accordance with the required electromagnetic wave passage rate. Also,
The shape may be such that a large number of elongated holes are uniformly distributed.

Furthermore, an opening may be formed over the entire circumference of the mirror 28, and the reflecting mirror may be divided into a plurality of pieces.

Lightning 1 magnetic wave transmission ring 29 is a semicircular copper ring with a reflective surface at a predetermined angle, and is partially transparent mirror 287J.
) transmits and focuses the electromagnetic waves transmitted as linearly polarized waves to the target, and its cross-sectional shape is an ellipsoidal surface M!, which is composed of a part of an ellipsoidal layer focused on the central portion Sl. In particular, the electromagnetic waves are used to heat an object to be heated, such as a plasma (plasma).

The uninvented gyrotron device configured in this way is
The radial electromagnetic waves generated from the electron beam are resonated around the entire circumference and amplified, and can be efficiently transmitted in the direction of the sword-shaped heat target using staff-polarized waves. A desired electromagnetic wave can be extracted through the aperture, and a linearly polarized wave output can also be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a gyrotron device of the present invention, FIG. 2 is a partially cutaway perspective view showing the main parts of an embodiment of the present invention, and FIG. 3 explains the operation of a partially transmitting mirror and a reflecting mirror. FIG. 4 is a cross-sectional view showing a conventional gyrotron device. 19...electron beam, 20...electron gun%2131~
21C. 26...Magnetic coil, 1 sentence to Taiyi Zhao\Arashi Arrogance 28...
・Partially transparent mirror, 29...Mirror for electromagnetic wave transmission, 2
5...electronic heat dump, 2%...slot.

Claims (2)

[Claims] (1) An electron gun that generates an electron beam, a magnetic field generator that applies a magnetic field to the electron beam emitted from the electron gun, and an electromagnetic wave that is generated when the electron beam passes through the magnetic field. The inner wall surface of a hollow annular electric conductor that quasi-optically reflects electromagnetic waves propagating in the radial direction with respect to the running axis of the conductor is formed axially symmetrically, and the wall surface has a short side in the axial direction and a long side in the azimuth direction. 1. A gyrotron device comprising: a semi-optical resonator having a partially transmitting mirror body provided with a rectangular or elliptical opening. (2) A radio wave reflector is added at a position outside the resonant cavity that opposes the opening of the partially transmitting mirror book, and its reflecting surface includes a group of quadratic curves with at least one focal point at the center of the resonant cavity. A gyrotron device according to claim 1, characterized in that: