Microwave plasma torch generating device and automatic ignition method thereof

Abstract

The invention relates to a microwave plasma torch generating device and an automatic ignition method thereof. The generating device comprises a microwave plasma torch assembly and a microwave generating assembly, the microwave plasma torch assembly comprises a coaxial resonant cavity, a rectangular resonant cavity, a quartz tube and a metal nozzle; after the cavity body of the coaxial resonant cavity is communicated with the quartz tube, the quartz tube passes through the cavity body of the rectangular resonant cavity; the metal nozzle is inserted into the coaxial resonant cavity and the rectangular resonant cavity through one end of the coaxial resonant cavity; the microwave generation assembly generates microwaves input into the microwave plasma torch assembly; the resonant frequency of the microwave plasma torch assembly is the same as the frequency of microwaves; the problem that a metal tip or a gathering electric field cannot be placed in a microwave plasma torch generating device is solved, automatic ignition is achieved, and the microwave plasma torch is reliable and stable. In the prior art, a metal tip or a device for gathering an electric field is arranged in a generating device, so that the electrode pollution is caused.

Description

Technical Field

[0001] The present invention relates to the field of microwave plasma technology, in particular to a microwave plasma torch generating device and an automatic ignition method thereof. Background Art

[0002] The generation of plasma in the discharge tube of a microwave plasma torch requires that the electric field strength of the generator device reach the breakdown field strength of the working gas in order to ionize the working gas and produce active plasma components. The electric field strength required to excite plasma at atmospheric pressure is often much higher than the electric field strength required to maintain the plasma. In particular, in microwave plasma discharge, a high-intensity local electric field is required to excite the working gas to discharge. For continuous-wave microwave plasma discharge, only one ignition is required and then the excitation device is removed to maintain the plasma discharge process through continuous microwave input coupling. Therefore, in order to generate the breakdown field strength required for gas breakdown in the microwave plasma torch generator, a metal tip or a device for concentrating the electric field is generally provided in the generator. However, since these devices are not present in general microwave plasma torch generators, when performing microwave plasma ignition, a metal tip is required to manually or automatically break through the working gas to cause it to discharge and generate plasma.

[0003] Currently, the commonly used excitation device uses a Tesla coil or tungsten electrode at the waveguide coupling port to apply AC high voltage to ignite, or directly ignites by pumping the discharge area to a low pressure and then raising the pressure to atmospheric pressure. This ignition method has a low degree of automation, and the components required for tip discharge are complex, inconvenient to operate, lack stability and reliability, and have short component lifespans and are prone to wear and tear. Summary of the Invention

[0004] The present invention addresses the technical problems existing in the prior art and provides a microwave plasma torch generating device and an automatic ignition method thereof, thereby resolving the problem that a metal tip or a device that gathers an electric field cannot be placed in the microwave plasma torch generating device, achieving automatic ignition and making the microwave plasma torch reliable and stable; and reducing electrode contamination, which is generally caused by metal tips or devices that gather an electric field being placed in the generating device in the prior art.

[0005] According to a first aspect of the present invention, a microwave plasma torch generating device is provided, comprising: a microwave plasma torch assembly and a microwave generating assembly; the microwave plasma torch assembly comprises: a coaxial resonant cavity, a rectangular resonant cavity, a quartz tube and a metal nozzle; After the cavity of the coaxial resonant cavity is connected to the quartz tube, the quartz tube passes through the cavity of the rectangular resonant cavity; the metal nozzle passes through one end of the coaxial resonant cavity and is inserted into the cavity of the coaxial resonant cavity and the rectangular resonant cavity; The microwave generating assembly generates microwaves that are input into the microwave plasma torch assembly; The resonant frequency of the microwave plasma torch assembly is the same as the frequency of the microwaves.

[0006] On the basis of the above technical solution, the present invention can also make the following improvements.

[0007] Optionally, the microwave generating assembly includes: a magnetron and a water load; The water load 1 is provided with a circulator; the magnetron and the rectangular resonant cavity are respectively connected to two ends of the circulator of the water load 1; the magnetron generates microwaves which are input into the device.

[0008] Optionally, the generating device further comprises: a microwave measuring component for measuring the frequency of the microwave emitted by the magnetron, the microwave measuring component comprising: a waveguide with a coupler, a water load 2, and a spectrum analyzer; After the magnetron is connected to the first water load, the first water load is connected to the waveguide with a coupler, and then the waveguide with a coupler is connected to the second water load; Supplying water to the first water load and the second water load with water, and connecting a spectrum analyzer to the waveguide via a coaxial cable; The spectrum analyzer measures the frequency of the microwaves emitted by the magnetron. Optionally, the process of measuring the frequency of the microwave emitted by the magnetron by the microwave measurement component further includes: The minimum value, maximum value, and increase in amplitude of the microwave output power are set, and the microwave output power is increased from the minimum value to the maximum value in sequence according to the increase in amplitude. Based on the frequency of the maximum amplitude of the spectrum displayed by the spectrum analyzer, the corresponding relationship between the frequency of the microwave emitted by the magnetron and the microwave power is obtained.

[0009] Optionally, the generating device further comprises a resonance frequency measuring component for measuring the resonance frequency of the microwave plasma torch assembly, wherein the resonance frequency measuring component comprises: a network analyzer and a coaxial to rectangular waveguide; The network analyzer is connected to the coaxial-to-rectangular waveguide via a coaxial cable, and the rectangular portion of the coaxial-to-rectangular waveguide is connected to the microwave plasma torch assembly; The resonant frequency of the microwave plasma torch assembly is measured by the network analyzer.

[0010] Optionally, the microwave plasma torch assembly further includes: three pins arranged on the rectangular resonant cavity.

[0011] According to a second aspect of the present invention, there is provided a method for automatically igniting a microwave plasma torch generating device, comprising: Step 1, measuring the resonant frequency of the microwave plasma torch assembly and the frequency of the microwave generated by the microwave generating assembly; Step 2, adjusting the resonant frequency of the microwave plasma torch assembly and the frequency of the microwave generated by the microwave generating assembly to be the same; Step 3, connecting the microwave plasma torch assembly to the microwave generating assembly and supplying gas through the metal nozzle; Step 4: Turn on the power of the microwave generating assembly and increase the output microwave power according to a set increment until the plasma is ignited in the quartz tube.

[0012] Optionally, step 2 includes: Moving and adjusting the distance of the metal nozzle entering the coaxial resonant cavity and adjusting the three pins provided on the rectangular resonant cavity, adjusting the resonant frequency of the microwave plasma torch assembly to the frequency of the microwaves generated by the microwave generating assembly, and adjusting the output power of the microwaves generated by the microwave plasma torch assembly to 25%-60% of the maximum output power; The position of the metal nozzle is locked with a locking nut.

[0013] The present invention provides a microwave plasma torch generator and an automatic ignition method thereof, which achieve automatic ignition of microwave plasma and a continuous and stable plasma torch through the combination of a coaxial resonant cavity and a rectangular resonant cavity. The coaxial resonant cavity is located below the rectangular resonant cavity and is composed of a movable metal nozzle and a tangential gas supply. The tangential gas supply is mainly used for gas supply, which forms plasma after being excited by microwaves; the coaxial resonant cavity is mainly used for plasma ignition; and the rectangular resonant cavity is mainly used to maintain the continuous and stable operation of the plasma torch. Not only can automatic ignition be achieved, but the structure is simple and the operation is convenient. It can also reduce electrode contamination. In the prior art, the metal tip or the device that concentrates the electric field is generally provided in the generator, which causes electrode contamination. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic structural diagram of an embodiment of a microwave plasma torch generating device provided by the present invention; Figure 2 A schematic diagram of a simulation of the change in electric field intensity in a rectangular resonant cavity and a coaxial resonant cavity before and after plasma ignition provided by an embodiment of the present invention; Figure 3 A schematic diagram of the structure of a spectrum analyzer measuring a magnetron provided by an embodiment of the present invention; Figure 4 A diagram showing the relationship between the microwave output power and frequency of a magnetron provided in an embodiment of the present invention; Figure 5A schematic diagram of a structure for adjusting the resonant frequency of a resonant cavity provided by an embodiment of the present invention; Figure 6 A diagram showing simulation results of the resonant frequency of the resonant cavity at different nozzle positions provided by an embodiment of the present invention; In the accompanying drawings, the components represented by the reference numerals are as follows: 1. Magnetron, 2. Water load 1, 3. Three pins, 4. Metal nozzle, 5. Coaxial resonant cavity, 6. Rectangular resonant cavity, 7. Quartz tube, 11. Waveguide with coupler, 12. Water load 2, 13. Spectrum analyzer, 21. Network analyzer, 22. Coaxial to rectangular waveguide. DETAILED DESCRIPTION

[0015] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0016] Figure 1 A schematic structural diagram of an embodiment of a microwave plasma torch generating device provided by the present invention is shown in FIG. Figure 1 As shown, the device includes: a microwave plasma torch assembly and a microwave generating assembly; the microwave plasma torch assembly includes: a coaxial resonant cavity 5, a rectangular resonant cavity 6, a quartz tube 7 and a metal nozzle 4.

[0017] After the coaxial resonant cavity 5 is connected to the quartz tube 7, the quartz tube 7 passes through the cavity of the rectangular resonant cavity; the metal nozzle 4 passes through one end of the coaxial resonant cavity 5 and is inserted into the cavity of the coaxial resonant cavity 5 and the rectangular resonant cavity 6.

[0018] The microwave generating assembly generates microwaves that are input into the microwave plasma torch assembly.

[0019] The resonant frequency of the microwave plasma torch assembly is the same as the frequency of the microwaves.

[0020] like Figure 2 The figure shows a schematic diagram of the simulation of the change of the electric field intensity in the rectangular resonant cavity and the coaxial resonant cavity before and after the plasma ignition according to the embodiment of the present invention. Figure 2A coaxial resonant cavity is a microwave resonant device based on a coaxial structure. It consists of a coaxial conductor, including an inner conductor (center conductor) and an outer conductor (external shield), closed at both ends by short-circuit plates. It is suitable for broadband, low-loss applications. A rectangular resonant cavity, constructed from a cylindrical conductor, is closed at both ends by a metal cover, forming a closed cylindrical cavity. It is suitable for multi-band applications and high-power microwave systems. Coaxial resonant cavities have high mass and a sharp, narrow resonance curve, while cylindrical resonant cavities have low mass and a wide resonance curve. The high mass of the coaxial resonant cavity creates a high electric field at the tip of the metal nozzle, achieving the high electric field required for plasma ignition, thereby achieving plasma ignition. The low mass and wide resonance curve of the rectangular resonant cavity effectively maintain the continuous operation of the plasma torch ignited by the high electric field of the coaxial resonant cavity. Because plasma has a dielectric constant, once ignited within the resonant cavity, the dielectric constant of the entire cavity changes, causing the resonant frequency to shift. At this point, microwaves cannot penetrate the coaxial resonant cavity and are confined within the transparent quartz discharge tube. Since the dielectric constant of quartz is greater than 1, the volume of the cylindrical resonator is actually increased, resulting in a decrease in the resonant frequency of the resonant cavity. This phenomenon must be taken into account when designing the dimensions of the cylindrical resonant cavity.

[0021] The present invention provides a microwave plasma torch generator, which solves the problem that metal tips or devices that gather electric fields cannot be placed in the microwave plasma torch generator, realizes automatic ignition, and makes the microwave plasma torch reliable and stable; it can also reduce electrode contamination, which is generally caused by metal tips or devices that gather electric fields in the generator in the prior art.

[0022] Example 1 The embodiment 1 provided by the present invention is an embodiment of a microwave plasma torch generating device provided by the present invention, Figure 1 It can be seen that the embodiment of the generating device includes: a coaxial resonant cavity 5 , a rectangular resonant cavity 6 , a quartz tube 7 and a metal nozzle 4 .

[0023] After the coaxial resonant cavity 5 is connected to the quartz tube 7, the quartz tube 7 passes through the cavity of the rectangular resonant cavity; the metal nozzle 4 passes through one end of the coaxial resonant cavity 5 and is inserted into the cavity of the coaxial resonant cavity 5 and the rectangular resonant cavity 6.

[0024] The microwave generating assembly generates microwaves that are input into the microwave plasma torch assembly.

[0025] The resonant frequency of the microwave plasma torch assembly is the same as the frequency of the microwaves.

[0026] To achieve high-quality plasma ignition using a coaxial resonant cavity, the resonant frequency of the cavity must be precisely matched to the microwave frequency provided by the magnetron. Because all magnetrons do not emit their microwaves exactly at their nominal frequency, and because the frequency depends on the output power, the magnetron must be measured using a spectrum analyzer. To ensure that the resonant frequency of the coaxial resonant cavity matches the microwave frequency of the magnetron, a network analyzer is also used to measure the resonant frequency. The metal nozzle is moved up and down to precisely match the resonant frequency to the magnetron's microwave frequency. To achieve the high electric field at the nozzle tip required to ignite the plasma, a three-pin assembly is required. This is installed between the microwave plasma torch (which contains the metal nozzle, coaxial resonant cavity, rectangular resonant cavity, and quartz tube) and the magnetron. This three-pin assembly is adjusted to maximize forward power and minimize reflected power.

[0027] In a possible embodiment, the microwave generating assembly includes: a magnetron 1 and a water load 2.

[0028] The water load 2 is provided with a circulator; a magnetron 1 and a rectangular resonant cavity 6 are connected to both ends of the circulator of the water load 2 respectively; the magnetron 1 generates microwaves which are input to the device.

[0029] The circulator's function is to direct the input signal to the water load, while isolating reflected waves and protecting the source. The water load absorbs microwave energy through the water flow and is typically used in high-power applications such as radar testing or particle accelerators.

[0030] In one possible embodiment, Figure 3 The figure shows a schematic diagram of the structure of the spectrum analyzer for measuring the magnetron according to an embodiment of the present invention. Figure 3 It can be seen that the generating device further includes: a microwave measuring component for measuring the frequency of the microwaves emitted by the magnetron, and the microwave measuring component includes: a waveguide with a coupler 13, a water load 12 and a spectrum analyzer 11.

[0031] After the magnetron 1 is connected to the water load 1 2 , the water load 1 2 is connected to the waveguide with a coupler 13 , and then the waveguide with a coupler 13 is connected to the water load 2 12 .

[0032] Water load 1 2 and water load 2 12 are supplied with water, and a spectrum analyzer 13 is connected to the waveguide 11 through a coaxial cable.

[0033] The spectrum analyzer 13 measures the frequency of the microwaves emitted by the magnetron.

[0034] A waveguide with coupler is a passive microwave device that combines waveguide transmission and signal coupling functions. It is mainly used for directional transmission of electromagnetic waves (especially in the microwave frequency band), signal distribution, or power monitoring.

[0035] In practice, a 20dB attenuator is inserted into a spectrum analyzer, and the magnetron is powered on. The spectrum of the transmitted microwaves is displayed on the spectrum analyzer. The 20dB attenuator protects the spectrum analyzer from excessive power exceeding 1W.

[0036] A spectrum analyzer is a multi-purpose electronic measuring instrument that studies the spectral structure of electrical signals and is used to measure signal parameters such as distortion, modulation spectral purity, frequency stability, and intermodulation distortion. A spectrum analyzer is essential for measuring radio signals and a common tool in the R&D, production, and testing of electronic products. Therefore, it is widely used and is often referred to as the engineer's RF multimeter.

[0037] In a possible embodiment, the process of the microwave measurement component measuring the frequency of the microwave emitted by the magnetron further includes: The minimum, maximum, and increase in amplitude of the microwave output power are set, and the microwave output power is increased from the minimum value to the maximum value in sequence according to the increase in amplitude. Based on the frequency of the maximum amplitude of the spectrum displayed by the spectrum analyzer, the corresponding relationship between the frequency and microwave power of the microwave emitted by the magnetron is obtained.

[0038] like Figure 4 The diagram shows the relationship between the microwave output power and frequency of a magnetron according to an embodiment of the present invention. In practice, a magnetron with output power below 10% of its maximum output power typically exhibits a very broad spectrum with numerous distinct peaks, making it unusable. The microwave power was increased from 10% to the maximum output power in increments of 5% to 10%. The frequency of the maximum amplitude in the spectrum displayed by the spectrum analyzer was determined each time, yielding the corresponding relationship between the microwave output frequency and microwave power.

[0039] In one possible embodiment, Figure 5 The diagram shows a schematic diagram of a structure for adjusting the resonant frequency of a resonant cavity according to an embodiment of the present invention, Figure 5 It can be seen that the generating device further includes a resonance frequency measurement component for measuring the resonance frequency of the microwave plasma torch component, and the resonance frequency measurement component includes: a network analyzer 21 and a coaxial to rectangular waveguide 22 .

[0040] The network analyzer 21 is connected to the coaxial-to-rectangular waveguide 22 via a coaxial cable, and the rectangular portion of the coaxial-to-rectangular waveguide 22 is connected to the microwave plasma torch assembly.

[0041] The resonant frequency of the microwave plasma torch assembly is measured by a network analyzer 21 .

[0042] like Figure 6 Shown is a diagram showing simulation results of the resonant frequency of the resonant cavity provided by an embodiment of the present invention at different nozzle positions.

[0043] A network analyzer is a comprehensive microwave measuring instrument that can perform sweeping measurements within a wide frequency band to determine network parameters. Its full name is microwave network analyzer. A network analyzer is a new type of instrument for measuring network parameters. It can directly measure the complex scattering parameters of active or passive, reversible or irreversible two-port and single-port networks, and provide the amplitude, phase-frequency characteristics of each scattering parameter in a sweeping frequency manner. Automatic network analyzers can perform point-by-point error correction on the measurement results and convert dozens of other network parameters, such as input reflection coefficient, output reflection coefficient, voltage standing wave ratio, impedance (or admittance), attenuation (or gain), phase shift, group delay and other transmission parameters, as well as isolation and directivity. This patent mainly uses a network analyzer to measure the phase-frequency characteristics of passive microwave plasma torch components.

[0044] In a possible embodiment, the microwave plasma torch assembly further includes: three pins 3 arranged on the rectangular resonant cavity.

[0045] Example 2 Embodiment 2 provided by the present invention is an embodiment of an automatic ignition method of a microwave plasma torch generating device provided by the present invention, and the embodiment of the automatic ignition method includes: Step 1: measuring the resonance frequency of the microwave plasma torch assembly and the frequency of the microwave generated by the microwave generating assembly.

[0046] Step 2: Adjust the resonance frequency of the microwave plasma torch assembly and the frequency of the microwave generated by the microwave generating assembly to be the same.

[0047] In one possible embodiment, step 2 includes: Move and adjust the distance that the metal nozzle enters the coaxial resonant cavity and adjust the three pins set on the rectangular resonant cavity, adjust the resonant frequency of the microwave plasma torch assembly to the frequency of the microwave generated by the microwave generating assembly, and adjust the output power of the microwave generated by the microwave plasma torch assembly to 25%-60% of the maximum output power.

[0048] Lock the metal nozzle in place with the lock nut.

[0049] Step 3: Connect the microwave plasma torch assembly to the microwave generating assembly and supply gas through the metal nozzle.

[0050] In a specific implementation, a gas supply is connected to the microwave plasma torch and the gas supply valve is opened.

[0051] Step 4: Turn on the power of the microwave generating assembly and increase the output microwave power according to the set increment until plasma is ignited in the quartz tube.

[0052] In a specific implementation, the output power is adjusted to a low power of 10%, and the microwave power is slowly increased within 10 to 60 seconds until plasma is ignited in the quartz tube of the microwave plasma torch.

[0053] During subsequent use, steps 1-4 can be followed to achieve automatic ignition of atmospheric pressure microwave plasma.

[0054] It can be understood that the automatic ignition method of a microwave plasma torch generating device provided by the present invention corresponds to the microwave plasma torch generating devices provided by the aforementioned embodiments. The relevant technical features of the automatic ignition method of the microwave plasma torch generating device can refer to the relevant technical features of the microwave plasma torch generating device, and will not be repeated here.

[0055] The embodiment of the present invention provides a microwave plasma torch generator and an automatic ignition method thereof, which realizes automatic ignition of microwave plasma and a continuous and stable plasma torch through the combination of a coaxial resonant cavity and a rectangular resonant cavity. The coaxial resonant cavity is located below the rectangular resonant cavity and is composed of a movable metal nozzle and a tangential gas supply. The tangential gas supply is mainly used for gas supply and forms plasma after being excited by microwaves; the coaxial resonant cavity is mainly used for plasma ignition; and the rectangular resonant cavity is mainly used to maintain the continuous and stable operation of the plasma torch. Not only can automatic ignition be achieved, but the structure is simple and the operation is convenient. It can also reduce electrode contamination. In the prior art, metal tips or devices that concentrate electric fields are generally provided in the generator, which will cause electrode contamination.

[0056] It should be noted that, in the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0057] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0058] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0059] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0060] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0061] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0062] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A microwave plasma torch generating device, characterized in that: The device comprises: a microwave plasma torch assembly and a microwave generating assembly; the microwave plasma torch assembly comprises: a coaxial resonant cavity, a rectangular resonant cavity, a quartz tube and a metal nozzle; After the cavity of the coaxial resonant cavity is connected to the quartz tube, the quartz tube passes through the cavity of the rectangular resonant cavity; the metal nozzle passes through one end of the coaxial resonant cavity and is inserted into the cavity of the coaxial resonant cavity and the rectangular resonant cavity; The microwave generating assembly generates microwaves that are input into the microwave plasma torch assembly; The resonant frequency of the microwave plasma torch assembly is the same as the frequency of the microwaves.

2. The generating device according to claim 1, characterized in that The microwave generating assembly includes: a magnetron and a water load; The water load 1 is provided with a circulator; the magnetron and the rectangular resonant cavity are respectively connected to two ends of the circulator of the water load 1; the magnetron generates microwaves which are input into the device.

3. The generating device according to claim 2, characterized in that The generating device further comprises: a microwave measuring assembly for measuring the frequency of the microwaves emitted by the magnetron, the microwave measuring assembly comprising: a waveguide with a coupler, a water load 2 and a spectrum analyzer; After the magnetron is connected to the first water load, the first water load is connected to the waveguide with a coupler, and then the waveguide with a coupler is connected to the second water load; Supplying water to the first water load and the second water load with water, and connecting a spectrum analyzer to the waveguide via a coaxial cable; The spectrum analyzer measures the frequency of the microwaves emitted by the magnetron.

4. The generating device according to claim 3, characterized in that The process of the microwave measuring component measuring the frequency of the microwave emitted by the magnetron further includes: The minimum value, maximum value, and increase in amplitude of the microwave output power are set, and the microwave output power is increased from the minimum value to the maximum value in sequence according to the increase in amplitude. Based on the frequency of the maximum amplitude of the spectrum displayed by the spectrum analyzer, the corresponding relationship between the frequency of the microwave emitted by the magnetron and the microwave power is obtained.

5. The generating device according to claim 1, characterized in that The generating device further comprises a resonance frequency measuring component for measuring the resonance frequency of the microwave plasma torch component, wherein the resonance frequency measuring component comprises: a network analyzer and a coaxial to rectangular waveguide; The network analyzer is connected to the coaxial-to-rectangular waveguide via a coaxial cable, and the rectangular portion of the coaxial-to-rectangular waveguide is connected to the microwave plasma torch assembly; The resonant frequency of the microwave plasma torch assembly is measured by the network analyzer.

6. The generating device according to claim 1, characterized in that The microwave plasma torch assembly further includes three pins arranged on the rectangular resonant cavity.

7. An automatic ignition method for a microwave plasma torch generator according to any one of claims 1 to 6, characterized in that: The ignition method comprises: Step 1, measuring the resonant frequency of the microwave plasma torch assembly and the frequency of the microwave generated by the microwave generating assembly; Step 2, adjusting the resonant frequency of the microwave plasma torch assembly and the frequency of the microwave generated by the microwave generating assembly to be the same; Step 3, connecting the microwave plasma torch assembly to the microwave generating assembly and supplying gas through the metal nozzle; Step 4: Turn on the power of the microwave generating assembly and increase the output microwave power according to a set increment until the plasma is ignited in the quartz tube.

8. The automatic ignition method according to claim 7, characterized in that: The step 2 includes: Move and adjust the distance that the metal nozzle enters the coaxial resonant cavity and adjust the three pins set on the rectangular resonant cavity, adjust the resonant frequency of the microwave plasma torch assembly to the frequency of the microwave generated by the microwave generating assembly, and adjust the output power of the microwave generated by the microwave plasma torch assembly to 25%-60% of the maximum output power; and lock the position of the metal nozzle with a locking nut.

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