Oppositely directed dual electron beam terahertz gyrotron

Abstract

The application discloses a reverse direction double electron beam terahertz gyrotron, which comprises two cathodes, two first anodes, an inner rod, a second anode, a resonant cavity, an output straight waveguide, a radiator, a mirror surface, an output window sheet and a magnet. The application can flexibly control the quality of the two electron beams, can realize single-frequency high-power output of the gyrotron, can realize double-frequency double-mode output of the gyrotron, and can separately heat a certain emission band to achieve the effect that the gyrotron emits electron beams with different guide center radii to excite different modes.

Description

Technical Field

[0001] This invention belongs to the field of terahertz wave technology, specifically a dual-electron-beam terahertz gyroscope with opposite directions. Background Technology

[0002] Terahertz waves have wide applications in communications, spectroscopy, materials processing, and thermonuclear fusion. These applications have accelerated the development of high-power terahertz radiation sources. As a terahertz radiation source, optical devices can output milliwatt-level power in the terahertz band. Traditional vacuum devices, such as traveling wave tubes and extended interacting oscillators, cannot generate high-power terahertz waves because the physical size of the interaction cavity is inversely proportional to the operating frequency.

[0003] Based on electron cyclotron pulse plugs, cyclotrons can output terahertz waves in the watt to megawatt range because the interaction cavity of the cyclotron is a transmode cavity, and its physical size can be much larger than the operating wavelength. In recent years, cyclotrons have been applied in inorganic chemistry and biological sciences to explore unique phenomena.

[0004] Liu Shenggang and Liu Chaoyu disclosed a novel coaxial cavity dual-electron-beam gyroscope in Chinese Patent 200510022310.4. The emission bands of the two electron beams are on the same cathode, therefore the voltages of the two emission bands are the same, meaning the energies of the two electron beams are identical, making it difficult to control the quality of the electron beams. Furthermore, the two emission bands cannot be heated independently, making it difficult to achieve different excitation modes for electron beams with different guide center radii in the gyroscope. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-electron-beam terahertz gyroscope with opposite directions, so as to flexibly control the mass of the two electron beams; it can output high power at a single frequency or dual-frequency dual-mode; at the same time, it can heat a certain emission band separately to achieve the effect of gyroscope emitting electron beams with different guiding center radii to excite different modes.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A dual-electron-beam terahertz gyroscope with opposite directions includes two cathodes, two first anodes, an inner rod, a second anode, a resonant cavity, an output straight waveguide, a radiator, a mirror, an output window, and a magnet. The second anode is connected to the resonant cavity; the resonant cavity is connected to the output straight waveguide; and the output straight waveguide is connected to the radiator. The resonant cavity includes a cutoff section, a beam-wave interaction section, and an output tapered section; the cutoff section is connected to the beam-wave interaction section; and the beam-wave interaction section is connected to the output tapered section.

[0008] Furthermore, cathode one and cathode two are located at the two ends of the gyrotube.

[0009] Furthermore, the electron beams emitted by cathode one and cathode two are in opposite directions.

[0010] Furthermore, the first anode is located above the first cathode, and the second anode is located above the second cathode.

[0011] Furthermore, the inner rod is located on the central axis of the rotary tube.

[0012] Furthermore, the first anode two collects the electron beam emitted by the first cathode; the inner rod collects the electron beam emitted by the second cathode.

[0013] Furthermore, the angles of the cutoff segment and the output transition segment are respectively the cutoff segment angle a1 and the output transition segment angle a2, and a1≥5°, a2≤1.5°. The cutoff segment angle a1≥5° enables the terahertz wave generated by the electron beam emitted by cathode two to be reflected, and the propagation direction is the same as the electromagnetic wave generated by the terahertz beam emitted by cathode one.

[0014] Furthermore, the radiator has a helical cut shape.

[0015] Furthermore, the magnetic field generated by the magnet is used for the electron beam emitted by cathode one; the flat magnetic field is used for the electron beam emitted by cathode one to interact with the wave in the resonant cavity; the flat magnetic field is also used for the electron beam emitted by cathode two to interact with the wave in the resonant cavity; the decreasing magnetic field is used for the second anode two to collect the electron beam emitted by cathode one; the decreasing magnetic field is also used for the electron beam emitted by cathode two.

[0016] The beneficial effects of this invention are:

[0017] (1) The present invention has two different cathodes, which can make the voltages of the two cathodes different, thereby effectively controlling the quality of the two electron beams.

[0018] (2) The guiding center radii of the two electron beams can be located at the two peaks of the beam coupling coefficient of the same mode, which effectively improves the coupling between the electron beam and the mode, thereby increasing the power of the terahertz wave.

[0019] (3) The guiding center radius of the two electron beams can also be located at the two peaks of the beam coupling coefficient of different modes, generating two terahertz waves of different modes and frequencies.

[0020] (4) The two cathode emission bands can be heated separately to achieve the purpose of different modes and frequencies of electron beam excitation with different guiding center radii of the gyrotube. Attached Figure Description

[0021] Figure 1 A schematic diagram of a dual-electron-beam terahertz gyroscope structure with opposite directions is provided in an embodiment of the present invention;

[0022] Figure 2Schematic diagram of the resonant cavity;

[0023] Figure 3 This is a schematic diagram showing how terahertz waves are radiated by a radiator, reflected by a mirror, and passed through an output window.

[0024] Figure 4 The distribution of the magnetic field generated by the magnet;

[0025] Figure 5 The working mode is TE 85 The mode, with a working frequency of 500 GHz and a harmonic order of 2, is a gyrotube beam coupling coefficient.

[0026] Figure 6 The working mode is TE 04 The mode, with a working frequency of 220GHz and a harmonic order of 1, is a gyrotube beam coupling coefficient.

[0027] Figure 7 The working mode is TE 02 The mode is a gyrotube beam coupling coefficient with an operating frequency of 115 GHz and a harmonic order of 1.

[0028] Figure label: 1. Cathode 1; 2. Cathode 2; 3. First anode 1; 4. Inner rod; 5. Second anode; 6. Resonant cavity; 7. First anode 2; 8. Output straight waveguide; 9. Radiator; 10. Transmitting mirror; 11. Output window; 12. Magnet; 13. Cutoff section; 14. Beam-wave interaction section; 15. Output gradient section; b1. Electron beam emitted from cathode 1; b2. Electron beam emitted from cathode 2; s1. Terahertz wave generated by the electron beam emitted from cathode 1; s2. Terahertz wave generated by the electron beam emitted from cathode 2. Implementation

[0029] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0030] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0031] like Figure 1The diagram shown is a schematic of a dual-electron-beam terahertz gyroscope structure provided in this embodiment. The gyroscope specifically comprises a cathode 1, a cathode 2, a first anode 3, a second anode 7, an inner rod 4, a second anode 5, a resonant cavity 6, an output straight waveguide 8, a radiator 9, a mirror 10, an output window 11, and a magnet 12. The second anode 5 is connected to the resonant cavity 6; the resonant cavity 6 is connected to the output straight waveguide 8; and the output straight waveguide 8 is connected to the radiator 9. The resonant cavity 6 includes a cutoff section 13, a beam-wave interaction section 14, and an output tapered section 15; the cutoff section 13 is connected to the beam-wave interaction section 14; and the beam-wave interaction section 14 is connected to the output tapered section 15.

[0032] Cathode 1 and Cathode 2 are located at the two ends of the gyrotube.

[0033] The electron beam b1 emitted by cathode 1 is in the opposite direction to the electron beam b2 emitted by cathode 2.

[0034] The first anode 3 is located above the cathode 1 and is used to control the transverse and longitudinal velocity ratio, velocity dispersion, and other electron beam quality of electron beam b1. The second anode 7 is located above the cathode 2 and is used to control the transverse and longitudinal velocity ratio, velocity dispersion, and other electron beam quality of electron beam b2.

[0035] The inner rod is located on the central axis of the rotary tube.

[0036] After electron beam b1 emitted from cathode 1 participates in beam-wave interaction, electron beam b1 is collected by first anode 7; after electron beam b2 emitted from cathode 2 participates in beam-wave interaction, electron beam b2 is collected by inner rod 4.

[0037] The radiator has a spiral cut shape and is used to radiate terahertz waves.

[0038] The structure of the resonant cavity 6 is as follows Figure 2 As shown, the angles of the cutoff segment 13 and the output transition segment 15 are the cutoff segment angle a1 and the output transition segment angle a2, respectively, and a1≥5°, a2≤1.5°. The cutoff segment angle a1≥5° can reflect the terahertz wave s1 generated by the electron beam b2 emitted by cathode 2, and the propagation direction is the same as the direction of the electromagnetic wave generated by the electron beam b1 emitted by cathode 1.

[0039] like Figure 3 As shown, the terahertz wave s1 generated by electron beam b1 is radiated by radiator 9 to reflector 10, and then emitted by reflector 10 to output window 11, whereby the terahertz wave s1 is output. The terahertz wave s2 generated by electron beam b2 is radiated by radiator 9 to reflector 10, and then emitted by reflector 10 to output window 11, whereby the terahertz wave s2 is output.

[0040] The magnetic field generated by magnet 12 is as follows Figure 4As shown, a slowly increasing magnetic field is used for the electron beam b1 emitted by cathode 1; a flat magnetic field is used for the electron beam b1 emitted by cathode 1 to interact with the resonant wave in the resonant cavity; a flat magnetic field is also used for the electron beam b2 emitted by cathode 2 to interact with the resonant wave in the resonant cavity; a decreasing magnetic field is used for the second anode 7 to collect the electron beam b1 emitted by cathode 1; a decreasing magnetic field is also used for the electron beam b2 emitted by cathode 2.

[0041] This invention has two different cathodes, which can have different voltages, thereby effectively controlling the quality of the two electron beams.

[0042] The expression for the wavelet coupling coefficient is:

[0043] Among them, G mn It is the wave coupling coefficient, s is the harmonic order, and J is the wave coupling coefficient. m±s It is a Bessel function, k mn It is TE mn The cutoff wavenumber of the mode, r b It is the radius of the electron beam's guiding center, v mn For TE mn The pattern is Bessel rooted, and m is the angular exponent.

[0044] The guiding center radii of the two electron beams can be located at the two peaks of the beam coupling coefficient of the same mode, which effectively improves the coupling between the electron beam and the mode, thereby increasing the power of the terahertz wave.

[0045] The guiding center radii of the two electron beams can also be located at the two peaks of the coupling coefficients of the beams in different modes, generating two terahertz waves of different modes and frequencies.

[0046] The two cathode emission bands can be heated separately to achieve the purpose of emitting electron beams with different guiding center radii to excite different modes and frequencies in the gyrotube.

[0047] Example 1: In this embodiment, the frequency is 500GHz, the harmonic order is the second harmonic, and the operating mode is TE. 85 The mode of the gyrotube, the beam coupling coefficient is as follows Figure 5 As shown. The guiding center radius of electron beam b1 emitted by cathode 1 is 1.12 mm, and the guiding center radius of electron beam b2 emitted by cathode 2 is 0.71 mm. The operating frequency of terahertz wave s1 is 500 GHz, and the operating mode is TE85; the operating frequency of terahertz wave s2 is 500 GHz, and the operating mode is TE85. This effectively improves the coupling between the 500 GHz terahertz wave and the electron beam, achieving the effect of increasing power.

[0048] Example 2: In this embodiment, the frequency is 220GHz, the harmonic order is 1, and the operating mode is TE. 04 The mode of the gyrotube, the beam coupling coefficient is as follows Figure 6 As shown. The frequency is 115GHz, the harmonic order is 1, and the operating mode is TE. 02 The mode of the gyrotube, the beam coupling coefficient is as follows Figure 7 As shown. The guiding center radius of electron beam b1 emitted by cathode 1 is 0.75 mm, and the guiding center radius of electron beam b2 emitted by cathode 2 is 0.4 mm. The terahertz wave s1 operates at a frequency of 220 GHz and in TE mode. 04 The terahertz wave S2 operates at a frequency of 115 GHz in TE mode. 02 The mode achieves dual-frequency dual-mode output of the gyrotube.

[0049] Example 3: In this embodiment, only cathode 1 is heated, while cathode 2 is not heated, which is equivalent to turning off cathode 2. The electron beam b1 emitted by cathode 1 has a guiding center radius of 0.75 mm. The terahertz gyroscope operates at a frequency of 220 GHz and in TE mode. 04 model.

[0050] Example 4: In this embodiment, only cathode 2 is heated, while cathode 1 is not heated, which is equivalent to turning off cathode 1. The electron beam b2 emitted by cathode 2 has a guiding center radius of 0.4 mm. The terahertz gyroscope operates at a frequency of 115 GHz and in TE mode. 02 model.

[0051] Examples 3 and 4 achieved the goal of using electron beams with different guiding center radii to excite different modes and frequencies in terahertz gyroscopes.

[0052] The above description is only used to illustrate the technical solution of the present invention and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention, as long as they do not depart from the spirit and scope of the technical solution of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A terahertz gyroscope with opposite-direction dual-electron-beam configuration, characterized in that, It includes cathode one and cathode two, first anode one and first anode two, inner rod, second anode, resonant cavity, output straight waveguide, radiator, mirror, output window and magnet; the second anode is connected to the resonant cavity; the resonant cavity is connected to the output straight waveguide; the output straight waveguide is connected to the radiator; the resonant cavity includes a cutoff section, a beam-wave interaction section and an output gradient section; The cutoff section is connected to the beam-wave interaction section; the beam-wave interaction section is connected to the output gradient section; cathode one and cathode two are located at both ends of the gyrotube; the electron beams emitted by cathode one and cathode two are in opposite directions; the first anode one is located above cathode one, and the first anode two is located above cathode two.

2. The terahertz gyroscope with opposite-direction dual-electron-beam configuration according to claim 1, characterized in that: The inner rod is located on the central axis of the rotary tube.

3. The terahertz gyroscope with opposite-direction dual-electron-beam configuration according to claim 1, characterized in that: The first anode collects the electron beam emitted by the first cathode; the inner rod collects the electron beam emitted by the second cathode.

4. The terahertz gyroscope with opposite-direction dual-electron-beam configuration according to claim 1, characterized in that: The angles of the cutoff segment and the output transition segment are respectively the cutoff segment angle a1 and the output transition segment angle a2, and a1≥5°, a2≤1.5°; the cutoff segment angle a1≥5° can make the terahertz wave generated by the electron beam emitted by cathode two reflected, and the propagation direction is the same as the electromagnetic wave generated by the terahertz beam emitted by cathode one.

5. The terahertz gyroscope with opposite-direction dual-electron-beam configuration according to claim 1, characterized in that: The radiator has a spiral cut shape.

6. The terahertz gyroscope with opposite-direction dual-electron-beam configuration according to claim 1, characterized in that: The magnetic field generated by the magnet has a slowly increasing magnetic field used for the electron beam emitted by cathode one; a flat magnetic field used for the electron beam emitted by cathode one to interact with the wave in the resonant cavity; a flat magnetic field also used for the electron beam emitted by cathode two to interact with the wave in the resonant cavity; a decreasing magnetic field used for the second anode two to collect the electron beam emitted by cathode one; and a decreasing magnetic field also used for the electron beam emitted by cathode two.

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