JPH03170089A - High frequency radiation device - Google Patents

Abstract

PURPOSE:To facilitate standardization and improve economy by installing a module constituted by combining an antenna for electron cyclotron heating, antenna for low-frequency mixed wave current driving, and an antenna for fast wave heating and current driving together. CONSTITUTION:A high frequency of several hundreds of MHz for the fast wave heating and current driving is propagated in the space between the internal conductor 15 and external conductor of a coaxial tube and supplied to a load, and the signal is radiated as an electromagnetic wave from a loop antenna 10 in the air and coupled with plasma to heat ions and generate a current in the plasma. In this case, three high frequencies of several hundreds of MHz, GHz, and several GHz are radiated in the air and coupled with plasma nearby an electrostatic shield to perform plasma generation, heating, and current driving at the same time. Further, electric power of about 2MW is radiated from eight circular opening antennas with a 50mm internal diameter, about 16MW is radiated from eight loop antennas which are 60cm long and 20cm wide, and 5MW is radiated from a grill launcher formed by bundling 180 rectangular waveguides which are 7cm high and 1cm wide.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device that radiates high-frequency energy into the air or vacuum, and in particular, it is used to heat the plasma of a tokamak device, which is a torus-shaped magnetic confinement fusion device. Or, it relates to a high-frequency radiation device suitable for a device that excites a current in plasma. [Prior Art] Conventionally, torus-type nuclear fusion devices, particularly tokamak-type nuclear fusion devices, have been equipped with various types of heating devices in order to generate high-temperature, high-density plasma within the device.

Many types of heating devices have been proposed6.Among these, the most reliable ones are neutral particle injection heating devices and fast wave heating devices for heating the plasma center, and electron cyclotrons for heating the plasma periphery. There is a high frequency heating device. Additionally, many devices are installed to generate plasma current to confine plasma within the device. As a highly reliable plasma current drive device that generates plasma current, we have developed a device that is designed to be more advantageous in current generation than heating by partially modifying the neutral particle injection heating device and the fast wave heating device. (These are called neutral particle incident current drive devices, fast wave current drive devices, etc.). Furthermore, there is a low-frequency hybrid wave current drive device as an effective means for controlling the spatial distribution of plasma current. These devices have advantages and disadvantages depending on their characteristics, so tokamak-type fusion devices require at least the above-mentioned neutral particle injection heating, current deception device, fast wave heating, and It is efficient to install a current drive device, a low-frequency mixed wave current drive device, and an electron cyclotron heating device.6 Regarding the method of installing these various types of devices in a tokamak device, the Japan Atomic Energy Research Institute report JAERI-M 88 -0
90 (1988) in a paper titled ``Next-generation Nuclear Fusion Device Design - Comprehensive Report 1''. In this method, a large number of vacuum ports 50 and neutron shielding 51 are provided between toroidal coils 52 as shown in FIG. Fast wave current drive device 53
is installed, that is, one type of device is installed at each port.

[Problem to be solved by the invention]

The above conventional technology is based on installing one type of device in one port, and in a large fusion reactor class device, three are installed for the neutral particle injection device, and two are installed for the fast wave heating and current drive device. One port for the electron cyclotron heating device, and one port for the low-frequency mixed current drive device, making a total of seven boats occupied by these devices. However, the number of ports that can be installed in a tokamak-type fusion device is limited by the number of toroidal coils, and is about 12.6 Therefore, the number of ports that can be used for purposes other than heating and current drive is five at most. The problem is that there are not enough ports for measurements, material testing, blanket installation, etc.

Additionally, the heating device and current drive device need to be removed from the tokamak fusion device several times a year for maintenance. Tokamak-type fusion devices require disassembly and assembly by remote control in order to be activated, and with conventional technology, large-scale equipment with different shapes for remote control is prepared for each heating current drive device, which increases the number of devices. If this increases, the cost for remote control will become enormous in the construction of a nuclear fusion device.

An object of the present invention is to provide a heating and current drive device by providing a configuration in which an antenna for electron cyclotron heating, an antenna for low-frequency mixed wave current drive, and an antenna for fast wave heating and current drive can be installed in one port. The goal is to reduce the number of ports required for

Another object of the present invention is to install a plurality of modules that combine antennas for electron cyclotron heating, low-frequency hybrid wave current drive antennas, fast wave heating and current drive antennas in a tokamak-type nuclear fusion device. The purpose of this configuration is to reduce the types of equipment required for disassembly and assembly, thereby improving economic efficiency.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a 100 Gl{z band for electron cyclotron heating on the inside of the inner conductor of a coaxial tube that supplies high frequency power in the 100 MHz band to a loop antenna for fast wave heating and fast wave current drive. Used as a μ wave waveguide. In addition, the 100 MHz band high frequency oscillator consists of a reference oscillator section that generates low power high frequency waves and an amplifier section that amplifies the high frequency waves, and a 100 GHz band μ wave waveguide passes through the high frequency cavity resonator of the amplifier section. then 1 0
A loop for taking out 0 MHz band high frequency output is formed.

Furthermore, in order to modularize the electron cyclotron heating antenna, the low-frequency hybrid wave current drive antenna, and the fast wave heating and current drive antenna, the fast wave heating and fast wave current drive loop antennas are connected to the return conductor. The short-circuited part at the tip is made of a rectangular tube and used as a grill launcher from which a high-frequency wave for excitation of low-frequency mixed waves is radiated.The part connecting the above loop antenna to the coaxial pipe conductor is made into a circular opening antenna and is used for electron cyclotron heating from there. Emit microwaves for use.

[Effect]

In the coaxial transmission line of the present invention, the space inside the inner conductor is a circular waveguide for μ wave transmission, and the space between the inner conductor and the outer conductor is 100 MHz.
It operates as a TEM line that transmits band high frequencies. As a result, high frequencies of a plurality of frequencies can be transmitted through a single transmission line, so the space for arranging the transmission line can be reduced, and the construction period required for installing the transmission line can be shortened.

Further, the modular antenna of the present invention operates as an antenna that integrates an electronic cyclotron heating antenna, a low-frequency mixed wave current drive antenna, a fast wave current drive, and a heating antenna. This makes it possible to transport and install multiple types of antennas as one device, and facilitates disassembly and assembly.

Furthermore, the electron cyclotron heating μ-waves radiated from the circular loop antenna generate and heat the plasma, and the low-frequency hybrid wave excitation μ-waves radiated from the grill launcher in the short-circuited portion of the loop antenna stimulate the peripheral portions of the plasma. A current is generated, and the fast-wave heating and current-driving high frequency waves radiated from the loop antenna heat the ions in the plasma, and further generate a current in the center of the plasma. As a result, the multiple types of high-frequency waves radiated from a narrow area have a synergistic effect that increases the efficiency with which other high-frequency waves are excited into the plasma, thereby improving the efficiency of plasma heating and current drive.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure shows a specific embodiment of the device according to the invention. In FIG. 1, 10 is a loop antenna, 32 is a return conductor, 5 is a coaxial tube inner conductor that also serves as a circular conductor tube, 30 is a grill launcher made of a bundle of rectangular waveguides, and 11 is an electrostatic shield. The high frequency wave for fast wave heating and current driving with a frequency of several hundred MHz propagates through the space between the inner conductor 5 of the coaxial tube and the outer conductor 31 of the coaxial tube, and consists of a loop antenna 10, a grill launcher 30, and a return conductor 32. The electromagnetic wave is supplied to the load, is radiated into the air as an electromagnetic wave from the loop antenna 10, combines with the plasma, heats the ions, and generates a current in the plasma. The electrostatic shield 1 shields electrostatic waves that adversely affect the plasma and prevents them from being radiated into the plasma region. The μ waves with a frequency of several hundred GHz that have propagated inside the coaxial pipe conductor 5 are transmitted through the opening 4.
It is radiated into the air from 0 and performs plasma vigilance and electronic heating. The μ waves having a frequency of several Gllz propagated through the four rectangular waveguides are radiated into the air from the grill launcher 30 and generate current in the plasma. According to this embodiment, several hundred MH
High frequencies of three frequencies, z, several hundred GHz, and several GHz, are radiated into the air and combine with the plasma existing near the electrostatic shield of this embodiment, allowing the operations of plasma generation, heating, and current drive to be performed simultaneously. . Further, according to this embodiment, approximately 2 MW is generated from eight circular aperture antennas each having an inner diameter of 5 olm.
Approximately 16 MW of power can be radiated from eight loop antennas with a length of 60 (1) and a width of 20 cm, and approximately 5 MW of power can be radiated from a grill launcher that bundles 180 rectangular waveguides with a height of 7CfII and a width of 1 cm, and a similar module can be used in a tokamak type. If three of them are installed in a nuclear fusion device, it will be possible to supply more than 50 MW of power, which is necessary for a large reactor-sized device.

Furthermore, the grille launcher for driving a low-frequency mixed wave current according to this embodiment is composed of rectangular waveguides arranged in 90 rows and two stages. Conventional launchers have a multi-stage structure of six to eight stages of rectangular waveguides in order to radiate a large amount of high-frequency power from a single port, and designing the layout of the cooling pipes to cool the launcher has become a difficult issue. However, since the launcher of this embodiment has a large space on the back side of the return conductor, there is no problem like that of the conventional example.

FIG. 3 is a diagram showing another embodiment for radiating high frequencies of two frequencies, several hundred MHz and several hundred GHz, together with the low frequency amplifier section of the high frequency oscillator. The low frequency 100 MHz band high frequency generated by the reference oscillator section is guided from the high frequency input lo 21 to the high frequency cavity resonator 17 and amplified by the amplifier tube 20. Furthermore, the μ-waves in the hundreds of GHz band pass through the high-frequency cavity resonator 17 and are radiated from the opening 40 through the coaxial pipe conductor connected to the μ-wave input lo 22. The high frequency wave in the 100 MHz band amplified by the amplifier tube 20 is taken out by the high frequency coupling loop 16, and is connected to the inner conductor 1 of the coaxial tube.
5 and the outer conductor l3 and is guided to the loop antenna 10. According to this embodiment, several hundred MHz and several hundred GH
Two types of high frequency waves, z, are supplied to a coaxial tube that also serves as a circular waveguide, and transmitted to the antenna, where they can be radiated into the air.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below. That is, since radio waves of different frequencies can be transmitted through one transmission path and radiated from the integrated antenna, the radio frequency system can be made smaller. In addition, waves can be excited in the plasma by emitting high-frequency waves with different properties from spatially localized locations, which improves the efficiency of wave excitation, plasma heating, and current drive. Furthermore, since a plurality of antennas and transmission lines having the same structure are installed, standardization is easy and economical efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1 is a front view (a) and a side view (
b), Figure 2 shows the arrangement of a conventional high-frequency radiator, and Figure 3 shows a top view of one half of a tokamak-type nuclear fusion device, and Figure 3 shows the antenna part and the low-frequency high-frequency amplifier part of the high-frequency oscillator in the second embodiment of the present invention. FIG. 10...Loop antenna, 15...Coaxial pipe inner conductor and circular waveguide, 31...Coaxial pipe outer conductor, 32...Return 41 111 @ 4 Rotatami figure 3 day use! 4-row tatami

Claims (1)

[Claims] 1. A high-frequency radiating device comprising a high-frequency oscillator that generates high-frequency waves, a high-frequency transmission line that transmits high-frequency waves, and an antenna that radiates high-frequency waves into the air or vacuum, wherein the high-frequency transmission line includes a plurality of conductive conductors. Consisting of coaxial cylinders, the inner cylinder acts as a waveguide through which high-frequency waves propagate, and the area between two adjacent outer cylinders acts as a TEM line through which low-frequency waves propagate, and the antenna acts as a waveguide through which high-frequency waves propagate. A high frequency radiating device comprising a part that emits the highest frequency and a part that emits a low frequency. 2. In claim 1, the radio frequency radiation is applied to a device that generates and heats plasma in a nuclear fusion device that confines plasma by a magnetic field, or excites a plasma current in a nuclear fusion device that confines plasma by a magnetic field. The high-frequency wave used for electron cyclotron heating or electron cyclotron current drive has a frequency that matches an integral multiple of the electron cyclotron frequency in the plasma, and the low-frequency wave has a frequency that matches an integral multiple of the electron cyclotron frequency in the plasma. A high frequency radiation device that is a high frequency for fast wave heating or fast wave current driving that is higher than the ion cyclotron frequency and lower than the electron cyclotron frequency. 3. The high frequency radiating device according to claim 1, wherein the part that radiates the highest frequency is a circular aperture antenna. 4. The high-frequency radiating device according to claim 1, wherein the portion that radiates low-frequency high-frequency waves is a plate antenna or a loop antenna. 5. In claim 1, the high-frequency oscillator includes the first oscillator portion that generates a high-frequency wave with a high frequency;
A waveguide that transmits the high frequency output of the first oscillator section, comprising a second oscillator section that generates the low frequency high frequency wave, and an amplifier section that amplifies the low frequency high frequency output of the second oscillator section. A high-frequency radiating device that penetrates through a high-frequency cavity resonator included in an amplifier portion and is connected to the high-frequency transmission path. 6. A high-frequency radiating device in the plate antenna or the loop antenna according to claim 4, in which the portion connecting the antenna conductor to the return conductor is constituted by a rectangular cylinder, and the high-frequency wave is also radiated from the cylinder.