Planar resonant cavity for planar gyrotron and methods to improve output power

Abstract

This disclosure provides a planar resonant cavity for a planar gyrotron and a method for increasing its output power, relating to the field of microwave technology. The planar resonant cavity includes: a resonant cavity for increasing the energy of electromagnetic waves; wherein the energy of the electromagnetic waves gradually increases based on the interaction between the electron beam and the electromagnetic wave; electron emitting surfaces, respectively disposed at the upper and lower ends of the cavity surface in the negative Z direction, for emitting electron beams; wherein the electron emitting surfaces at the upper and lower ends of the cavity surface are symmetrical based on both the central YZ plane and the central XZ plane of the resonant cavity; and baffles, including a left baffle and a right baffle, the left and right baffles having identical structures, respectively disposed in the X direction of the resonant cavity between the electron emitting surfaces and the two ends of the resonant cavity, for reflecting electromagnetic waves to enhance the interaction between the electron beam and the wave, increase the energy of the electromagnetic waves, and increase the output power of the electromagnetic waves.

Description

Technical Field

[0001] This disclosure relates to the field of microwave technology, and more specifically, to a planar resonant cavity for a planar gyrotube and a method for increasing output power. Background Technology

[0002] Planar gyrotrons, utilizing strip electron beams and transverse electromagnetic energy extraction to replace cylindrical gyrotron structures, offer higher output power and mode selection advantages. However, the dual-planar resonant cavity of related planar gyrotrons, while achieving a relatively low maximum output power through adjustments to the output waveguide structure and cavity dimensions, cannot effectively improve the transverse output power, resulting in a significant discrepancy from theoretical calculations. Summary of the Invention

[0003] In view of this, the present disclosure provides a planar resonant cavity for a planar gyrotube and a method for improving output power.

[0004] One aspect of this disclosure discloses a planar resonant cavity for a planar gyrotube, comprising: a resonant cavity for increasing the energy of electromagnetic waves; wherein the energy of the electromagnetic waves gradually increases according to the interaction between the ribbon electron beam and the electromagnetic wave beam; electron emitting surfaces, respectively disposed at the upper and lower ends of the cavity surface in the negative Z direction of the resonant cavity, for emitting the ribbon electron beam; wherein the electron emitting surfaces located at the upper and lower ends of the cavity surface are symmetrical based on both the central YZ plane and the central XZ plane of the resonant cavity; and baffles, including a left baffle and a right baffle, wherein the left baffle and the right baffle have the same structure. The components are respectively disposed in the X direction of the resonant cavity between the electron emitting surface and the two ends of the resonant cavity to reflect the electromagnetic waves, thereby enhancing the wave-beam interaction, increasing the energy of the electromagnetic waves, and increasing the output power of the electromagnetic waves; wherein, the distance between the end of the left baffle and the resonant cavity is equal to the distance between the end of the right baffle and the resonant cavity; the left baffle includes an upper baffle and a lower baffle, which are symmetrical about the central XZ plane of the resonant cavity; there is a gap between the upper baffle and the lower baffle so that the electromagnetic waves are output from the gap.

[0005] According to embodiments of this disclosure, the baffles are designed with different positions and widths in the X direction, and different depths in the upper and lower baffles in the Y direction, so that the electromagnetic waves can be output with maximum output power.

[0006] According to embodiments of this disclosure, the baffle is also suitable for generating a uniform electromagnetic field to enhance the aforementioned wave-splitting interaction.

[0007] According to an embodiment of this disclosure, the cavity of the planar resonant cavity is a vacuum; the planar resonant cavity is immersed in a magnetic field.

[0008] According to embodiments of this disclosure, the electron emitting surface is also suitable for injecting the strip-shaped electron beam into the resonant cavity at a predetermined angle and a predetermined speed, so that the energy carried by the strip-shaped electron beam is transferred to the electromagnetic wave.

[0009] According to an embodiment of this disclosure, the planar resonant cavity further includes: a sudden change segment, a protruding segment disposed on the cavity surface in the negative Z direction of the resonant cavity, the height of the sudden change segment being lower than the height of the cavity surface in the negative Z direction of the resonant cavity; and electron emitting surfaces disposed at the upper and lower ends of the sudden change segment, respectively.

[0010] According to an embodiment of this disclosure, the planar resonant cavity further includes: a gradually changing section, with two of the gradually changing sections symmetrically arranged at both ends of the resonant cavity.

[0011] According to an embodiment of this disclosure, the planar resonant cavity further includes a waveguide, wherein two waveguides are respectively connected to two gradually changing sections and are symmetrically arranged at both ends of the two gradually changing sections, and are suitable for outputting the electromagnetic waves.

[0012] According to an embodiment of the present disclosure, the cavity surface in the positive Z direction of the resonant cavity is configured as an opening; the abrupt change segment is configured as an opening; and the two ends in the X direction of the two waveguides away from the two gradual change segments are configured as openings.

[0013] Another aspect of this disclosure discloses a method for increasing the output power of a planar resonant cavity for a planar gyrotube.

[0014] According to embodiments of this disclosure, by setting two baffles in the lateral direction of the resonant cavity on both sides of the strip electron beam, electromagnetic waves can be reflected or reflected multiple times, which enhances the beam-wave interaction between the strip electron beam and the electromagnetic waves, effectively improving the lateral output power and bringing it closer to the theoretical prediction value. Attached Figure Description

[0015] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0016] Figure 1 A schematic diagram of the structure of a planar resonant cavity in the related art is shown.

[0017] Figure 2A A schematic diagram of the structure of a planar resonant cavity for a planar gyrotube according to an embodiment of the present disclosure is shown.

[0018] Figure 2BA schematic cross-sectional view in the XY direction of a planar resonant cavity for a planar gyrotube according to an embodiment of the present disclosure is shown.

[0019] Figure 2C A schematic cross-sectional view in the YZ direction of a planar resonant cavity for a planar gyrotube according to an embodiment of the present disclosure is shown.

[0020] Figure 3A A schematic diagram illustrating the electric field distribution of a planar resonant cavity without baffles according to an embodiment of the present disclosure is shown.

[0021] Figure 3B A schematic diagram illustrating the electric field distribution of a planar resonant cavity for a planar gyrotube according to an embodiment of the present disclosure is shown.

[0022] Figure 4A This schematically illustrates the amplitude of the simulated output electromagnetic wave of a planar resonant cavity without a baffle according to an embodiment of the present disclosure; and

[0023] Figure 4B The diagram schematically illustrates the amplitude of the simulated output electromagnetic wave of a planar resonant cavity for a planar gyrotube according to an embodiment of the present disclosure. Detailed Implementation

[0024] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0026] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0027] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0028] Gyrotrons possess the potential to generate megawatt-level output power and are of great significance as terahertz radiation sources, with wide applications in fields such as nuclear fusion plasma heating and high-power radar. Gyrotrons operate based on electron cyclotron pulsation technology, a mechanism that converts electron kinetic energy into electromagnetic radiation energy, utilizing the stimulated emission of free electrons in a magnetic field. With continuously increasing operating frequencies, the output power of cylindrical gyrotrons is limited by their inherent power capacity, exhibiting a rapid decline. Planar gyrotrons, however, offer higher output power and mode selection advantages, thus possessing enormous application potential.

[0029] Replacing the cylindrical gyrotube scheme with a strip gyro beam and transverse electromagnetic energy extraction significantly improves performance. The dual-planar cavity high-frequency structure of the strip gyro beam offers advantages such as uniform operating mode field distribution, relatively low ohmic loss, transverse diffraction mode selection capability, favorable harmonic operation, and convenient frequency tuning.

[0030] Figure 1 A schematic diagram of the structure of a planar resonant cavity in the related art is shown.

[0031] like Figure 1 As shown, the "lateral" in the above-mentioned transverse electromagnetic energy extraction refers to the X-direction. With a given initial velocity and incident angle, the electron beam enters the resonant cavity and undergoes beam-wave interaction. Under relativistic effects, angular clustering occurs, and the transverse energy carried by the electrons is transferred to the electromagnetic wave, amplifying its energy. A high-energy electromagnetic wave is then output from the transverse outlet of the resonant cavity.

[0032] In a simple dual-planar resonant cavity, the maximum output power that can be obtained by adjusting the structure of the output waveguide and the size of the resonant cavity itself is relatively low, and the lateral output power cannot be effectively improved, which is quite different from the theoretical calculation value.

[0033] This disclosure provides a planar resonant cavity for a planar gyrotron and a method for increasing output power, comprising: a resonant cavity for increasing the energy of electromagnetic waves; wherein the energy of the electromagnetic waves gradually increases according to the interaction between the ribbon electron beam and the electromagnetic wave beam; electron emitting surfaces, respectively disposed at the upper and lower ends of the cavity surface in the negative Z direction of the resonant cavity, for emitting ribbon electron beams; wherein the electron emitting surfaces at the upper and lower ends of the cavity surface are symmetrical based on both the central YZ plane and the central XZ plane of the resonant cavity; and baffles, including a left baffle and a right baffle. The left and right baffles have identical structures and are respectively positioned in the X-direction of the resonant cavity between the electron emitting surface and the two ends of the resonant cavity. They are used to reflect electromagnetic waves to enhance the beam-wave interaction, increase the energy of the electromagnetic waves, and increase the output power of the electromagnetic waves. The distance between the end of the left baffle and the end of the resonant cavity that is close to the resonant cavity is equal to the distance between the other end of the right baffle and the end of the resonant cavity that is close to the resonant cavity. The left baffle includes an upper baffle and a lower baffle, which are symmetrical about the XZ plane of the resonant cavity. There is a gap between the upper baffle and the lower baffle so that the electromagnetic waves can be output from the gap.

[0034] According to embodiments of this disclosure, by setting two baffles in the lateral direction of the resonant cavity on both sides of the strip electron beam, electromagnetic waves can be reflected or reflected multiple times, which enhances the beam-wave interaction between the strip electron beam and the electromagnetic waves, effectively improving the lateral output power and bringing it closer to the theoretical prediction value.

[0035] The following will combine Figure 2A , Figure 2B and Figure 2C The structure of the planar resonant cavity used in a planar gyrotube is described.

[0036] Figure 2A A schematic diagram of the structure of a planar resonant cavity for a planar gyrotube according to an embodiment of the present disclosure is shown.

[0037] Figure 2B A schematic cross-sectional view in the XY direction of a planar resonant cavity for a planar gyrotube according to an embodiment of the present disclosure is shown.

[0038] Figure 2C A schematic cross-sectional view in the YZ direction of a planar resonant cavity for a planar gyrotube according to an embodiment of the present disclosure is shown.

[0039] like Figure 2A As shown, the planar resonant cavity 200 for a planar gyrotube includes a resonant cavity 1, an electron emission surface 2, a sudden change section 3, a gradual change section 4, a baffle 5, and a waveguide 6.

[0040] According to embodiments of this disclosure, the interior of the planar resonant cavity 200 is a vacuum; the planar resonant cavity 200 is immersed in a magnetic field, for example, a magnetic field generated by a spiral coil. The housing of the planar resonant cavity 200 may be an oxygen-free copper housing.

[0041] According to embodiments of this disclosure, resonant cavity 1 is used to increase the energy of electromagnetic waves. The energy of the electromagnetic waves gradually increases due to the interaction between the ribbon electron beam and the electromagnetic wave beam. Resonant cavity 1 is the beam-wave interaction segment.

[0042] According to an embodiment of this disclosure, electron emitting surfaces 2 are respectively disposed at the upper and lower ends of the cavity surface in the negative Z direction of the resonant cavity 1 for emitting a strip-shaped electron beam; wherein, the electron emitting surfaces 2 located at the upper and lower ends of the cavity surface are symmetrical based on both the central YZ plane and the central XZ plane of the resonant cavity 1.

[0043] According to embodiments of this disclosure, the electron emitting surface 2 is also suitable for injecting a strip-shaped electron beam into the resonant cavity 1 at a predetermined angle and a predetermined velocity. The strip-shaped electron beam interacts with the electromagnetic wave in the resonant cavity 1, and the strip-shaped electron beam undergoes angular clustering under relativistic effects, so that the energy carried by the strip-shaped electron beam is transferred to the electromagnetic wave, thereby amplifying the energy of the electromagnetic wave.

[0044] In one example, a ribbon electron beam is used to generate a target electromagnetic field, and the distribution and power of the electromagnetic field are modulated.

[0045] According to an embodiment of this disclosure, the baffle 5 includes a left baffle and a right baffle. The left baffle and the right baffle have the same structure and are respectively disposed in the X direction of the resonant cavity 1 between the two ends of the electron emitting surface 2 and the resonant cavity 1. They are used to reflect electromagnetic waves to enhance the interaction between the electron and the wave, increase the energy of the electromagnetic waves, and increase the output power of the electromagnetic waves.

[0046] According to an embodiment of this disclosure, the distance between the left baffle and the end of the resonant cavity 1 that is close to it is equal to the distance between the right baffle and the other end of the resonant cavity 1 that is close to it. The left baffle includes an upper baffle and a lower baffle, which are symmetrical about the central XZ plane of the resonant cavity 1 to facilitate better transmission of electromagnetic waves. A gap is provided between the upper baffle and the lower baffle to allow electromagnetic waves to be output from the gap.

[0047] According to embodiments of this disclosure, the baffle 5 is designed with different positions and widths in the X direction, as well as different depths in the upper and lower baffles in the Y direction, so that electromagnetic waves can be output with maximum output power.

[0048] Figure 3A A schematic diagram illustrating the electric field distribution of a planar resonant cavity without baffles according to an embodiment of the present disclosure is shown.

[0049] Figure 3BA schematic diagram of the electric field distribution of a planar resonant cavity for a planar gyrotube according to an embodiment of the present disclosure is shown.

[0050] According to embodiments of this disclosure, the baffle 5 is also used to generate a uniform electromagnetic field, the electric field distribution being as follows: Figure 3B As shown, this is to enhance the interaction between the beam and the wave. The electric field distribution of the planar resonant cavity without baffles is as follows. Figure 3A As shown, the baffle 5 reflects electromagnetic waves to a certain extent, enhancing the electric field strength within the resonant cavity 1, making the electric field distribution in the X direction within the resonant cavity 1 more uniform, thereby improving the interaction between the ribbon electron beam and the electromagnetic waves.

[0051] According to an embodiment of this disclosure, the abrupt segment 3 is disposed on a protruding segment of the cavity surface in the negative Z direction of the resonant cavity 1. The height of the abrupt segment 3 is lower than the height of the cavity surface in the negative Z direction of the resonant cavity 1, so as to cut off the transmission of electromagnetic waves in the negative Z direction. Electron emitting surfaces 2 are respectively disposed at the upper and lower ends of the abrupt segment 3.

[0052] According to an embodiment of this disclosure, two gradually varying segments 4 are symmetrically arranged at both ends of the resonant cavity 1. The gradually varying segments 4 change the height in the Y direction to increase the output power of the electromagnetic wave.

[0053] According to embodiments of this disclosure, two waveguides 6 are respectively connected to two gradually changing sections 4 and are symmetrically arranged at both ends of the two gradually changing sections 4 for lateral output of electromagnetic waves. The thickness of the waveguides 6 in the X direction also helps to improve the output power of the electromagnetic waves.

[0054] According to an embodiment of this disclosure, the cavity surface of the resonant cavity 1 in the positive Z direction is configured as an opening to transmit a strip-shaped electron beam. A planar gyrotube is connected to a collector electrode in the positive Z direction of the resonant cavity 1 to collect remaining electrons. The abrupt change segment 3 is configured as an opening to connect to the electron gun. The two ends of the two waveguides 6 in the X direction, away from the two gradual change segments, are configured as openings to transmit electromagnetic waves.

[0055] According to embodiments of this disclosure, a method for increasing the output power of a planar resonant cavity for a planar gyrotube is simulated using three-dimensional electromagnetic calculation software.

[0056] Figure 4A The diagram illustrates the amplitude of the simulated output electromagnetic wave of a planar resonant cavity without a baffle according to an embodiment of the present disclosure.

[0057] Figure 4B The diagram schematically illustrates the amplitude of the simulated output electromagnetic wave of a planar resonant cavity for a planar gyrotube according to an embodiment of the present disclosure.

[0058] According to embodiments of this disclosure, the incident voltage of the strip electron beam is set to 60 kV, the current to 60 A, and the tilt angle of the electron emitting surface to 50°. Simulation results show the amplitude of the simulated output electromagnetic wave of the planar resonant cavity without a baffle. Figure 4A As shown, the amplitude is 600, which translates to an output power of 360kW.

[0059] According to an embodiment of this disclosure, the distance between the left baffle and the left end of the electron emitting surface in the X direction is set to 1.55 mm, the depth of the upper and lower baffles of the left baffle is 1.3 mm, and the width of the left baffle is 0.6 mm. The right baffle has the same structure as the left baffle, and the distance between the right baffle and the right end of the electron emitting surface in the X direction is 1.55 mm. The amplitude results of the simulated output electromagnetic wave of the planar resonant cavity used for the planar gyrotron are obtained through simulation as follows: Figure 4B As shown, the amplitude is 750, which translates to an output power of 562kW. Compared to the output without a baffle, the output power increases by 56.1%.

[0060] According to embodiments of this disclosure, under the same resonant cavity size and the same output waveguide action, setting appropriate baffle positions and depths can effectively increase the output power of the planar resonant cavity in the lateral direction.

[0061] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A planar resonant cavity for a planar gyrotube, characterized in that, include: A resonant cavity is used to increase the energy of electromagnetic waves; wherein, the energy of the electromagnetic waves gradually increases according to the interaction between the ribbon electron beam and the electromagnetic wave beam. Electron emitting surfaces are respectively disposed at the upper and lower ends of the cavity surface in the negative Z direction of the resonant cavity, for emitting the strip-shaped electron beam; wherein, the electron emitting surfaces located at the upper and lower ends of the cavity surface are symmetrical about both the central YZ plane and the central XZ plane of the resonant cavity; The baffle includes a left baffle and a right baffle, the left baffle and the right baffle have the same structure and are respectively disposed in the X direction of the resonant cavity between the electron emitting surface and the two ends of the resonant cavity, for reflecting the electromagnetic wave to enhance the wave-electromagnetic interaction, increase the energy of the electromagnetic wave, and increase the output power of the electromagnetic wave; The distance between the left baffle and the end of the resonant cavity is equal to the distance between the right baffle and the end of the resonant cavity; the left baffle includes an upper baffle and a lower baffle, which are symmetrical about the XZ plane of the center of the resonant cavity; there is a gap between the upper baffle and the lower baffle so that the electromagnetic wave is output from the gap.

2. The planar resonant cavity for a planar gyrotube according to claim 1, characterized in that: The baffles are designed with different positions and widths in the X direction, as well as different depths in the upper and lower baffles in the Y direction, so that the electromagnetic waves can be output with maximum output power.

3. A planar resonant cavity for a planar gyrotube according to claim 1, characterized in that: The baffle is also suitable for generating a uniform electromagnetic field to enhance the wave-splitter interaction.

4. A planar resonant cavity for a planar gyrotube according to claim 1, characterized in that: The planar resonant cavity is a vacuum; the planar resonant cavity is immersed in a magnetic field.

5. A planar resonant cavity for a planar gyrotube according to claim 1, characterized in that: The electron emitting surface is also adapted to inject the strip electron beam into the resonant cavity at a predetermined angle and a predetermined velocity, so that the energy carried by the strip electron beam is transferred to the electromagnetic wave.

6. A planar resonant cavity for a planar gyrotube according to claim 1, characterized in that, Also includes: A sudden change segment is a protruding segment of the cavity surface in the negative Z direction of the resonant cavity, and the height of the sudden change segment is lower than the height of the cavity surface in the negative Z direction of the resonant cavity; the electron emission surface is respectively disposed at the upper and lower ends of the sudden change segment.

7. A planar resonant cavity for a planar gyrotube according to claim 6, characterized in that, Also includes: The two gradually varying segments are symmetrically arranged at both ends of the resonant cavity.

8. A planar resonant cavity for a planar gyrotube according to claim 7, characterized in that, Also includes: Two waveguides are respectively connected to two gradually varying sections and are symmetrically arranged at both ends of the two gradually varying sections, suitable for outputting electromagnetic waves.

9. A planar resonant cavity for a planar gyrotube according to claim 8, characterized in that: The cavity surface in the positive Z direction of the resonant cavity is configured as an opening; The mutation segment is configured as an opening; The two ends of the two waveguides in the X direction away from the two gradually changing segments are configured as openings.

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