JPS60115132A - Ultrahigh frequency electron tube - Google Patents

Abstract

PURPOSE:To obtain a high efficiency and high power electron tube in milliwave and submilliwave bands that succeeds in the features of Peniotron and Gyrotron by specifying the cyclotron angular frequency of the spiral movement of an electron beam and the Doppler-shifted angular frequency of a TE mode electromagnetic wave. CONSTITUTION:A high frequency circuit 4 contains a cylindrical cavity resonator 5 that resonates in TE021 mode at the operating frequency of a tube, at its center. An electron gun 2 side has a small diameter section so that the TE02 mode can be cut off and a connector 6 side has a large diameter so that the TE02 mode can be propagated. In addition, by adjusting a solenoid 9 so that the cyclotron angular frequency omegac of the spiral movement of an electron beam 3 for the Doppler-shifted angular frequency omega of the TE021 mode electromagnetic wave of the circular cylindrical cavity resonator 5 can satisfy a formula omega= (2n-1)omegac, an intense interaction occurs between the electron beam 3 and the TE021 mode electromagnetic wave of the cylindrical cavity resonator 5 and the kinetic energy of the electron beam 3 is converted into electric energy and then a high power electromagnetic wave is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a millimeter wave system that oscillates or amplifies electromagnetic waves by the interaction between an electron beam moving in a helical direction in a DC magnetic field and a TE mode electromagnetic wave in a cavity resonator or waveguide. and high-power tube tubes in the submillimeter wave band.

In recent years, highly efficient large power sources in the millimeter to submillimeter wave bands have been sought in the fields of fusion research and radar-resolution radar research. As a large power source in such a frequency band,
So far, Beniodron and Gyrotron are known.

Beniodron is produced by the interaction between a bell-shaped electron beam moving in a spiral direction in a DC magnetic field and an electromagnetic wave propagating in a high-frequency circuit of a double-ridge pair waveguide. It is an electron tube that amplifies or oscillates electromagnetic waves based on the phase separation effect. In Beniodron, the phase separation effect causes all of the simulator beams to be captured by the electromagnetic wave deceleration electric field, so the electron beam can be separated from the electron beam by Makoto Kamede.
As the conversion efficiency of energy, C is 100% in principle.
It has the advantage that a similar value can be expected, and that the intensity of the DC magnetic field can be lowered by utilizing the interaction between the harmonics of the cycloton frequency ωC of the ripple ζ motion of the electron beam and electromagnetic waves. However, since a pencil-shaped electron beam is used, the DC input power of the electron beam is limited, and furthermore, since a double ridge pair waveguide is used as the high frequency circuit, the high frequency electric field strength at the ridge part is limited. Since the power is limited from the viewpoint of safety, the output power of the tubes realized so far is at the level of several kW or tb.

On the other hand, the gyrotron was published in July 1977 in a famous American miscellaneous book, ZXBGG Dingransactions.
onTheory ancl Tecbuiq)ue
SIVOILLIl18 MTT-25 member 514 to page 527 paper r 'I'he Gyrotron
The system disclosed in J. J. is composed of a cylindrical electron beam moving in a DC magnetic field and a cylindrical frequency circuit such as a cylindrical cavity resonator or a circular waveguide, and is based on the relativistic effect of the electron beam. It is an electron tube that amplifies or oscillates electromagnetic waves. In the gyrotron, the center of the helical motion of the electron beam is arranged in an annular shape, so it is possible to increase the DC input power of the electron beam9, and the high-frequency circuit is structurally simple. has the advantage of increasing power capacity. However, in the collective action of the electron beam due to the relativistic effect, a portion of the electron beam is captured by the accelerating electric field of the electromagnetic wave, so high efficiency operation like that of Beniodron cannot be expected. Further, although it is theoretically possible for harmonics of the cyclotron frequency ωC to interact with electromagnetic waves, there is a problem in that the efficiency decreases significantly in harmonic operation, as described in the above-mentioned paper.

An object of the present invention is to provide a high-efficiency, high-power electron tube in the millimeter wave and submillimeter wave bands that inherits only the features of the beniodoron and gyrotron.

FIG. 1 is an overall view of an ultra-high frequency electron tube 1 embodying the present invention. The figure shows an electron gun assembly 2 for forming and emitting a cylindrical electron beam 3, a high frequency circuit 4, a collector electrode 6, ,
A structure is shown in which the output window 7 and the output waveguide 8 are arranged on the tube axis 10.

The solenoid 9 generates a high-intensity DC magnetic field in a portion connected to the high frequency circuit 4.

The high frequency circuit 4 includes a circular tube cavity resonator 5 in its center that resonates in the TEo□ mode at the tube operating frequency ω0,
TE on the electron gun side! There is a small diameter part where the mode is cut off, and the collector side is TE. , the diameter is increased to allow mode propagation. Cylindrical cavity resonator 5
By adjusting the solenoid 9, the electron A strong interaction occurs between the beam 3 and the TEO21 mode electromagnetic wave of the cylindrical cavity resonator 5, and the kinetic energy of the electron beam 3 is converted into electrical energy, generating a high-power electromagnetic wave.

ω-(2n 1)ωC(1) However, ■ is a positive integer, and the phase velocity of the electromagnetic wave is υp.
Then, the velocity component of the Naruko beam 3 in the direction of the tube axis 11 is υ,
Then, ω-(1±υ#/υp)ω0.

A high-power electromagnetic wave generated inside the cylindrical cavity resonator 5 is guided through the collector 6 and the output window 7 from the output waveguide 8 to an external load.

FIG. 2 is a cross-sectional view showing the electric field distribution of the TEO21 mode in the cavity resonator 5 and the arrangement of the electron beam 3.

In the T EOI11 mode, the first electric field ring 21 and the second electric field ring 22 are spatially oriented in opposite directions, and the center of the helical motion of the electron beam 3 is set between the first ring 21 and the second ring 22. They are arranged in a circular pattern.

FIG. 3 is a diagram showing a curve 31 showing a change in the electric field strength Eθ of the T Eoz+ mode in the cavity resonator 5 in the radial γ direction and an arrangement region 32 of the electron beam in the γ direction. The peak positions of the electric field strengths of the first electric field ring 21 and the second electric field ring 22 are set to γ1. γ, and the center position of the r1 motion of the electron beam 3 is γ. , and the diameter of the spiral motion is D, the relationship between these is as follows.

γ east < ro < r, 12) D γ 2 − γ l (3) As shown in FIG. As the distance increases, the polarity reverses and its absolute value increases.

FIG. 4 shows one helical line of the electron beam 3 arranged annularly in an electric field having such an intensity distribution and a change curve 31 of the electric field intensity Eθ in the r direction.

First, consider an electron that experiences a deceleration phase in the second electric field ring 22 on the right side of the figure, by reducing its radius of rotation and moving its center of rotation to the second electric field ring side, that is, on the pressure side, that is, in the first field ring. This will flow into the electric field ring 21. Now, if the condition of equation (1) holds true, what these electrons experience on the first electric field ring side is an acceleration phase, but due to the previous decrease in the radius of rotation and movement of the center of rotation, the 2 On the electric field ring side, the acceleration phase should be seen in the weak part of the electric field, and if you look at it per revolution, this electron is giving its kinetic energy to the electromagnetic wave. Moreover, the acceleration on the first electric field ring side also causes the center of rotation to move to the second turtle ring side, so in subsequent rotations - the effect of deceleration on the second electric field ring side becomes more and more dominant. Eventually, the kinetic energy comes to be imparted to the electromagnetic waves on the second electric field ring side without flowing into the first free field ring side.

On the other hand, even for electrons that experience an acceleration phase on the second electric field ring side when first entering the electric field space, the above process is simply reversed, and the deceleration effect of 2 on the first electric field ring side is When the electric field is larger than that on the ring side (#) per rotation, kinetic energy is similarly imparted to the electromagnetic wave and it eventually becomes attached to the first ring side. therefore,
The incident electron beam 3 is separated into two groups according to the incident phase of each electron into the electric field space, and both of them impart their kinetic energy to the electromagnetic wave and contribute to the layer width of the 'tiijB wave. However, in such a mechanism, high conversion efficiency can be expected because there are no undesirable electrons that receive energy from electromagnetic waves as in the operating mechanism of a normal traveling wave tube or gyrotron.

Furthermore, compared to conventional beniodorons, the ultrahigh-frequency electron tube of the present invention is capable of high-power operation because there is no restriction on the high-frequency electric field strength due to the ridge gap and the power of the incident electron beam can be increased.

Furthermore, since high efficiency operation can be maintained even at cyclotron harmonics, a high-power ultrahigh-frequency electron tube with low magnetic field strength can be realized even in the millimeter wave and submillimeter wave bands.

The cavity resonator TEoyt mode shown here is just one example; other 'W modes can also be used. In addition, by using a waveguide as a high-frequency circuit, υ can be increased by 1@
tube can be realized.

[Brief explanation of drawings]

FIG. 1 is an overall view of an ultra-high frequency electron tube embodying the present invention. FIG. 2 is a cross-sectional view showing the electric field distribution of the 1Eo21 mode in the cylindrical cavity resonator and the arrangement of the electron beam. Figure 3 shows the electric field strength Eθ of the TEo*t mode in the cylindrical cavity resonator.
A diagram showing the change in the radius r direction and the arrangement of the electron beam in the r direction. FIG. 4 shows a single fusion of the electron beam and a change curve of the magnetic field strength [Eθ in the r direction. 1... Super high frequency electron tube, 2... Sub gun assembly, 3... Electron beam, 4... Frequency circuit, 5... ...Cylindrical cavity resonator, 6...
...Collector electrode, 7...Output window, 8...
...Output waveguide, 9...Soleno 1, 10...
...Tube axis, 21...1st division ring, 2
2... Plate 2 electric field ring, 31... Radial change curve of electric field intensity, 32...' @ line showing the radial arrangement area of the electron beam. l/ Engraving of drawings (no change in content) @/ Figure 8Z Figure 3 Procedural amendment (method) Commissioner of the Patent Office 1, Indication of case 1988 Patent Application No. 221628
No. 2, Title of the invention Ultra-high frequency electron tube 3, Relationship with the amended person case Applicant 5-33-1 Shiba, Minato-ku, Tokyo (423) NEC Corporation Representative Tadahiro Sekimoto 4, Agent (liaison) Patent Department of NEC Corporation) 5. Date of amendment order: 28th Table of 2, 1989 (Shipping date) Specification and drawings 7, Contents of detention

Claims (1)

[Claims] In an ultra-high frequency electron tube based on the interaction between a cylindrical electron beam that moves linearly in a DC magnetic field and the center of the linear movement is arranged in an annular manner and a TE mode electromagnetic wave of a waveguide or cavity resonator, the TE The mode electromagnetic technique has two or more electric field components in which the direction of the electric field is opposite between walls, and the center of the helical motion of the electron beam is located in the middle of the opposite direction electric field components of the TE mode electromagnetic wave, '1 Between the cyclotron angular frequency ωC of the spiral motion of the child beam and the Doppler-shifted angular frequency ω of the TE mode electromagnetic wave, let n be a positive integer and ω=(
2n-1) An ultra-high frequency electron tube characterized by having the relationship ωC.