Gyrotron high-frequency interaction structure formed by continuous curves

Abstract

The invention discloses a gyrotron high-frequency interaction structure formed by continuous curves, which is characterized in that the gyrotron high-frequency interaction structure is composed of a cut-off section, an interaction section and an output section of a cubic spline difference fitting curve structure, and the curve slope at the joint of the cut-off section and the interaction section and the curve slope at the joint of the interaction section and the output section are consistent. Through the high-frequency interaction structure, a higher harmonic working mode can be excited in a terahertz frequency band, and the output characteristics of high efficiency and wide bandwidth are achieved. Under the working condition of a high-order axial mode, the gyrotron has stable output power and linear frequency change in the frequency adjusting process, and the effective working bandwidth is remarkably improved. The problems of power fluctuation and frequency hopping of the gyrotron under the working condition of a high-order axial mode are effectively solved, so that an excellent output effect is obtained.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of terahertz, and particularly relates to a gyrotron high-frequency interaction structure formed of a continuous curve. BACKGROUND

[0002] The special physical characteristics of terahertz waves are widely used in the field of enhanced nuclear magnetic resonance technology. This fast and accurate material detection technology is often applied in the fields of biology, medicine, chemistry, material science and the like, and has extremely broad research prospects and important research value. Stable and efficient terahertz sources are the focus of widespread attention. After continuous technical verification, the terahertz gyrotron has become a mainstream device for realizing a large power and high efficiency terahertz radiation source. In order to obtain a wider frequency tuning bandwidth, the terahertz gyrotron usually works in a high-order axial mode backwave operating area. However, the current terahertz gyrotron involves the conversion of adjacent high-order axial modes in the frequency tuning process. In this conversion process, there are problems such as a significant decrease in beam-wave interaction efficiency and frequency jump. Ultimately, the effective tuning bandwidth of the terahertz gyrotron is narrowed, and the output power at some frequency points is small. This seriously affects the stability of the gyrotron in realizing large power and high efficiency frequency conversion.

[0003] Changing the traditional three-section high-frequency interaction cavity structure is an effective way to improve the performance of the gyrotron device at present. In recent years, most researches have focused on the multi-section interaction cavity structure, that is, a transition section with an upper taper is added between the cutoff section and the interaction section, and between the interaction section and the output section, and the originally flat interaction section is changed to an interaction section with an upper taper. Through the above changes, the effective interaction length of each order of axial mode can be effectively changed, so as to reduce the starting current of the high-order axial mode and improve the interaction efficiency of the high-order mode. However, the fixed flat or straight line structure with an upper taper has a limited adjustment range, especially for gyrotrons working in high-order axial modes. The commonly used high-order axial mode operating area is basically in the backwave operating area. The backwave structure of the gyrotron high-frequency interaction cavity, especially the structure of the cutoff section and the output section, greatly affects the backwave operating characteristics of the gyrotron. The backwave operating characteristics of the gyrotron can be improved by a monotonous continuous curve. SUMMARY

[0004] The present application aims at providing a gyrotron high-frequency interaction structure of continuous curve, aiming at achieving high frequency, wide bandwidth, and stable output of high-power terahertz wave.

[0005] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0006] A gyrotron high-frequency interaction structure of continuous curve, characterized in that the cutoff section, the interaction section, and the output section of the resonant cavity are all cubic spline interpolation curve structures.

[0007] Further, the cutoff section is connected with the interaction section, and the interaction section is connected with the output section.

[0008] Further, the curve slopes at the connection positions of the cutoff section and the interaction section and the interaction section and the output section are consistent.

[0009] The present application has the following beneficial effects:

[0010] The present application designs a gyrotron high-frequency interaction structure of cubic spline interpolation curve structure, optimizes the return wave characteristics of the gyrotron on the basis of improving the interaction length of each axial mode, effectively realizes the high-efficiency output result of the gyrotron working in the high-order axial mode, effectively avoids the power drop problem caused by the transition between the high-order axial modes, and significantly improves the effective adjustment bandwidth of the gyrotron device. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 A gyrotron high-frequency interaction structure of continuous curve provided by the present application embodiment.

[0012] Figure 2 The effective interaction length of the TE 6.5.1 to TE 6.5.7 mode in the present application embodiment.

[0013] Figure 3 The starting current size of the TE 6.5.1 to TE 6.5.7 mode in the present application embodiment.

[0014] Figure 4 TE in the embodiments of the present invention 6.5 Image showing the output power of the model as a function of magnetic field strength.

[0015] Figure 5 TE in the embodiments of the present invention 6.5 Image showing the operating frequency of the model as a function of magnetic field strength.

[0016] In the attached diagram: 1. Cutoff segment; 2. Interaction segment; 3. Output segment. Detailed Implementation

[0017] 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.

[0018] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0020] This embodiment provides a high-frequency interaction structure for a gyrotron composed of continuous curves, such as... Figure 1 As shown, the high-frequency interaction structure of the gyrotron specifically includes a cutoff section 1, an interaction section 2, and an output section 3. The cutoff section, interaction section, and output section are all cubic spline interpolation curve structures. The cutoff section is connected to the interaction section, and the interaction section is connected to the output section; the slopes of the curves at the connection points are consistent.

[0021] The effective interaction length of each axial mode in the high-frequency interaction structure of the gyrotube, such as Figure 2 As shown. TE 6.5.1 To TE 6.5.7 The effective interaction lengths of the modes are all between 25 mm and 33 mm, with similar values, and the effective interaction length generally increases with the increase of the axial mode. This verifies that the gyrotube high-frequency interaction structure designed in this invention effectively adjusts the effective interaction lengths of each axial mode.

[0022] The magnitude of the initiation current for each axial mode in a gyrotube high-frequency interaction structure, such as Figure 3The starting current is the minimum current size that can excite the working mode under the working condition. The starting current of the TE651-TE657 modes is less than 0.1 A, and the starting current of the axial modes is similar. The high-frequency interaction structure of the gyrotron designed in the application significantly improves the starting current of the axial modes, especially the high-order axial modes. The gyrotron can be more stably switched between the axial modes when the gyrotron is tuned at the frequency of the high-order axial mode.

[0023] The output power of the working mode in the high-frequency interaction structure of the gyrotron varies with the magnetic field strength, as shown in FIG. 6. Figure 4 When the working voltage is 12 kV, the working current is 0.3 A, and the magnetic field strength is adjusted in the range of 7.19 T to 7.3 T, the output power of the working mode TE651-TE657 varies in the range of 20 W to 300 W. When the working voltage is 12 kV, the working current is 0.3 A, and the magnetic field strength is adjusted in the range of 7.19 T to 7.3 T, the output power of the working mode TE651-TE657 varies in the range of 20 W to 300 W. 6.5 The maximum output power of the mode is about 300 W, and the minimum output power is 20 W. When the gyrotron works in the high-order axial mode, it has stable output power in the magnetic field range of 7.25 T to 7.3 T, which is between 45 W and 75 W, and the output power changes relatively smoothly. The high-frequency interaction structure of the gyrotron designed in the application has stable output results when working in the high-order axial mode.

[0024] The working frequency of the working mode in the high-frequency interaction structure of the gyrotron varies with the magnetic field strength, as shown in FIG. 7. Figure 5 When the working voltage is 12 kV, the working current is 0.3 A, and the magnetic field strength is adjusted in the range of 7.19 T to 7.3 T, the working frequency varies from 394.65 GHz to 396.1 GHz, corresponding to a working bandwidth of about 1.5 GHz. In the magnetic field range of 7.25 T to 7.3 T, the frequency almost linearly changes with the increase of the magnetic field strength, and has good frequency tuning ability.

[0025] As can be seen from the above, the high-frequency interaction structure of the gyrotron provided by the application is composed of a special cutoff section, an interaction section, and an output section of a cubic spline interpolation curve structure. The return wave working characteristics of the gyrotron and the effective interaction length between the axial modes are effectively improved, so that the gyrotron can obtain a stable and efficient output result during frequency tuning in the high-order axial mode, effectively avoiding the power drop problem caused by the transition between the high-order axial modes, and significantly improving the effective tuning bandwidth of the gyrotron device.

[0026] The above description is only used to illustrate the technical solutions of the application but not to limit the application. Other modifications or equivalent replacements to the technical solutions of the application made by those skilled in the art should be covered in the scope of the claims of the application.

Claims

1. A high-frequency interaction structure of a gyrotube formed by continuous curves, characterized in that, A high-frequency interaction structure composed of three cubic spline difference fitting curves is presented. The gyrotron high-frequency interaction structure includes a cutoff section, an interaction section, and an output section, with the curves at the connections between the cutoff section and the interaction section, and between the interaction section and the output section, exhibiting consistent slopes. Within this gyrotron high-frequency interaction structure, a high-order harmonic operating mode can be excited in the terahertz band, possessing stable high beam-wave interaction efficiency and a wide effective frequency modulation bandwidth. Ultimately, this allows for a better transition between higher-order axial modes during gyrotron device operation, resulting in smoother and more efficient output power.

2. The high-frequency interaction structure of a gyrotube composed of a continuous curve according to claim 1, characterized in that, The cutoff segment, interaction segment, and output segment are all cubic spline interpolation curve structures.

3. The high-frequency interaction structure of a gyrotube composed of a continuous curve according to claim 1, characterized in that, The cutoff segment is connected to the interaction segment, and the interaction segment is connected to the output segment. Furthermore, the slope of the curve at the connection points between the cutoff segment and the interaction segment, and between the interaction segment and the output segment, is consistent.

4. The high-frequency interaction structure of a gyrotube composed of a continuous curve according to claim 1, characterized in that, The special high-frequency interaction structure enables gyrotron devices operating in higher-order axial modes to have stable high beam-wave interaction efficiency, and can effectively improve the power drop problem caused by the transition between adjacent higher-order modes, providing a wider effective frequency tuning bandwidth.

5. The high-frequency interaction structure of a gyrotube composed of a continuous curve according to claim 1, characterized in that, This gives the gyrotron better backwave operating characteristics, so that when tuning the frequency under high-order axial mode operating conditions, adjacent axial modes can transition better, resulting in a smoother output power.

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