CN1207944C - High power microwave plasma torch - Google Patents

Abstract

The invention relates to a high-power microwave plasma torch, which includes a tunable coaxial resonant cavity and a rectangular waveguide. A waveguide/coaxial conversion device is arranged inside the rectangular waveguide, and the waveguide/coaxial conversion device is a gate twist block and a medium The door torsion structure is fastened up and down on a single line. The waveguide/coaxial conversion device is closely connected with the upper and lower surfaces of the rectangular waveguide. The upper chamber, the lower chamber of the shaft, and the waveguide/coaxial conversion device are jointly formed. One end of the inner conductor is inserted into the lower chamber, and the other end runs through the dielectric single line, the door twist block, and the upper chamber in turn. The inner and outer conductors of the upper chamber are along the axis. A resonant cavity short-circuit piston is provided in the direction, a microwave source is provided at one end of the rectangular waveguide, and a waveguide short-circuit piston is provided at the other end. The invention solves the problems of complex excitation and maintenance mechanism, inconvenient adjustment, low power level, etc., and can be applied to gas phase chemical reaction, synthesis and processing of materials, and the like.

Description

High Power Microwave Plasma Torch

technical field

The invention relates to the field of plasma torches, in particular to a high-power microwave plasma torch.

Background technique

According to the method of excitation, plasma can be divided into conventional DC (AC) plasma, high frequency or radio frequency plasma, microwave induced plasma, laser plasma and thermally excited plasma. Plasma technology has been widely used in the preparation and processing of materials, thermonuclear reactions, and the treatment of toxic and hazardous waste. Conventional DC (AC) plasma is excited by forming a strong electric field strength (3000V/mm for air) between a pair of electrodes to break down the gas. In practical applications, conventional DC (AC) plasma has the disadvantages of short electrode life and electrode contamination due to high-temperature vaporization of the electrode. Although the electrode life can be improved by forced water cooling (currently reaching hundreds of hours), the application range of direct current (alternating current) plasma is still limited due to electrode contamination. High-frequency (RF) plasma is a non-polar discharge, and there is no problem of electrode pollution. It is used in the clean preparation of materials (such as etching of large-scale integrated circuits, vapor deposition, etc.), but the high-frequency (RF) plasma The electrical efficiency is very low, and the plasma can only couple 40-50% of the RF energy at most, and the higher the RF power, the lower the energy efficiency. In addition, the energy radiation of the radio frequency power supply to the air also causes electromagnetic pollution to the environment, and corresponding protection measures must be taken during use. Although laser-induced plasma is also an electrodeless discharge process, the high cost of equipment and low energy utilization efficiency also limit the feasibility of large-scale applications.

Microwave-induced plasma is another electrodeless discharge process. The existing microwave discharge structures can be summarized as follows: (1) excitation technology of capacitively coupled microwave plasma (CMP); (2) excitation technology of coaxial surface wave microwave plasma (Surfatron); (3) ) The excitation technology of waveguide-based surface wave microwave plasma (Surfaguide); (4) The excitation technology of TM ₀₁₀ resonant cavity (MIP) microwave plasma. The excitation mechanisms of these plasmas usually work under the condition of low power (≤1 kW), and are currently mainly used as plasma light sources for spectroscopic analysis. As the demand for plasma technology in the clean processing of materials, the treatment of toxic and hazardous waste, and the industrial application of plasma chemical synthesis continues to increase, research on microwave plasma torches suitable for various working gas media, high power, and high energy utilization has become an industrial topics of general interest. From the principle of microwave plasma excitation, most of the current microwave plasma excitation is the method of microwave resonant cavity, through the resonance of the microwave applicator, thereby forming a high electric field intensity in the local area of the microwave applicator, using The high electric field in the local area breaks down the gas medium, forming a plasma. Since the plasma excitation mechanism is designed using the microwave resonant cavity principle, when the plasma is formed, the effective load of the microwave resonant cavity and the resonant frequency of the microwave resonant cavity will inevitably change. In order to match the impedance of the entire microwave system and match the resonant frequency of the cavity with the frequency of the microwave source after the microwave plasma is generated, there must be an effective adjustment means to adjust the cavity. Recently, Massachusetts Institute of Technology has adopted two sets of microwave systems to achieve stable excitation and maintenance of microwave plasma. One set of microwave system is a microwave resonant cavity, which is responsible for the excitation of plasma; the other set of microwave system is a microwave traveling wave cavity, which is responsible for maintaining plasma. Through the optimized combination of two sets of microwave systems, the energy utilization rate of microwave can be increased to 95%. , the system can be suitable for various gas working media and high-power system work (greater than 4 kilowatts). A high-power microwave plasma excitation device has been reported by the University of Liverpool, UK. The device adopts the method of compressing the narrow side of the rectangular waveguide to form a local high electric field intensity area in the waveguide. By adjusting the compression degree of the waveguide and the position of the plasma excitation gas nozzle, the field strength at the gas nozzle reaches the maximum value. Under the microwave power (1-6 kilowatts), the excited gas is ionized to form plasma. A high-velocity gas stream is used to flush the plasma out of a narrow slot on the broad side of the microwave waveguide. Combining the existing high-power microwave plasma excitation devices, there are generally disadvantages of complex excitation and maintenance mechanisms and inconvenient adjustments. In addition, the current power level achieved is relatively low.

Contents of the invention

The purpose of the present invention is to provide a high-power microwave plasma torch that can solve the problems of complex excitation and maintenance mechanism, inconvenient adjustment, and low power level.

Technical scheme of the present invention is:

A high-power microwave plasma torch is characterized in that it includes a tunable coaxial resonant cavity and a rectangular waveguide, a waveguide/coaxial conversion device is arranged inside the rectangular waveguide, and the waveguide/coaxial conversion device is a door twist block and The door torsion structure of the dielectric single line buckled up and down, the waveguide/coaxial conversion device is closely connected with the upper and lower surfaces of the rectangular waveguide, and the tunable coaxial resonant cavity is located on the upper and lower sides of the waveguide and connected to the waveguide/coaxial conversion device Coaxial upper chamber, lower chamber, and waveguide/coaxial conversion device are jointly formed. The upper and lower chambers are coaxial with the outer conductor and the inner conductor. block, upper cavity, a resonant cavity short-circuit piston is arranged between the inner and outer conductors of the upper cavity along the axial direction, a microwave source is provided at one end of the rectangular waveguide, and a waveguide short-circuit piston is provided at the other end;

The dielectric single wire is composed of an inner conductor and a dielectric around it, and the dielectric constant ε of the dielectric material is less than or equal to 10;

The dielectric material is one of air, boron nitride, polytetrafluoroethylene, alumina, quartz or a composite thereof;

The frequency of the microwave source is 2450MHz, 915MHz or 314MHz; when the frequency of the microwave source is 2450MHz, and the dielectric material in the dielectric single wire adopts boron nitride, the main dimensions of the plasma torch device are: the outer diameter of the inner conductor D ₀ =4～ 30mm, the outer diameter of the dielectric single wire D ₁ =14~100mm, the length L ₁ of the inner conductor inserted in the lower chamber =30~300mm, the axial length of the dielectric single wire along the plasma torch L ₄ =20~54.6mm, the thickness of the door twist block L ₅ ＝0-34.6mm; when the frequency of the microwave source is 2450MHz, and the dielectric material in the dielectric single wire is alumina, the main dimensions of the plasma torch device are: the outer diameter of the inner conductor D ₀ ＝4～30mm, the outer diameter of the dielectric single wire D ₁ ＝10～60mm, length L ₁ of the inner conductor inserted in the lower chamber ＝30～300mm, length of dielectric single wire along the axial direction of plasma torch L ₄ ＝15～40mm, thickness of door twist block L ₅ ＝14～40mm; When the frequency of the microwave source is 2450MHz, and the dielectric material in the dielectric single wire is polytetrafluoroethylene, the main dimensions of the plasma torch device are: the outer diameter of the inner conductor D ₀ = 4 ~ 30mm, the outer diameter of the dielectric single wire D ₁ = 18 ~ 108mm , the length L ₁ of the inner conductor inserted in the lower cavity = 30-300mm, the length of the dielectric single wire along the axial direction of the plasma torch L ₄ = 30-54.6mm, the thickness of the door twist block L ₅ = 0-24.6mm; when the microwave source The frequency is 2450MHz, and the dielectric material in the dielectric single wire is quartz. The main dimensions of the plasma torch device are: the outer diameter of the inner conductor D ₀ = 4-30mm, the outer diameter of the dielectric single wire D ₁ = 14-90mm, and the inner conductor is inserted into the lower chamber The length L ₁ = 30-300mm, the axial length of the dielectric single line along the plasma torch L ₄ = 25-54.6mm, the thickness of the door twist block L ₅ = 0-30mm; when the frequency of the microwave source is 915MHz, the dielectric single line in the The material is boron nitride. The main dimensions of the plasma torch device are: the outer diameter of the inner conductor D ₀ =12-50mm, the outer diameter of the dielectric single wire D ₁ =60-220mm, the length of the inner conductor inserted into the lower chamber L ₁ =100 ~1200mm, the length of the single medium line L ₄ =40~124mm, the thickness of the door torsion block L ₅ =0~84mm.

The beneficial effects of the present invention are:

1. The excitation and maintenance mechanism is simple, easy to adjust, and the microwave incident power is large. According to the principle of microwaves, the present invention designs a new microwave plasma excitation scheme on the basis of analyzing existing plasma excitation devices. The tunable coaxial resonant cavity is used to realize the excitation of the plasma and the adjustment of the resonant frequency of the cavity after the plasma is generated, and the adjustment of the waveguide short-circuit piston is used to solve the problem of impedance mismatch caused by the plasma generation. The two sets of adjustment mechanisms are independent Work without interfering with each other. In order to meet the needs of high power and various working gas medium applications, the waveguide/coaxial conversion device with door twist structure and gas sealing structure are adopted. This device can work stably for a long time at a power of 20 kilowatts, and realizes the rectangular shape of microwave by using a single dielectric line. The energy coupling of the waveguide/tunable coaxial resonant cavity and the sealing of the gas enable the device to work stably under high power conditions, and at the same time, it is suitable for working environments that require a non-oxygen atmosphere.

2. Utilize the tunable coaxial resonant cavity to easily obtain the characteristics of the high-quality factor resonant cavity, and use the tunable coaxial resonant cavity to realize the excitation of microwave plasma of any working gas. Use the short-circuit piston of the tunable coaxial resonant cavity to correct the resonant frequency drift of the resonant cavity caused by the generation of plasma in real time, so that the resonant frequency of the tunable coaxial resonant cavity is always consistent with the operating frequency of the microwave power supply match.

3. The efficiency of the waveguide/coaxial conversion can be adjusted by using the short-circuit piston of the tunable coaxial resonant cavity, and the width of the narrow side of the rectangular waveguide can be properly compressed through the gate twist structure to provide guarantee for the strong coupling of the device in the cold state. The gate twist structure Cooperating with the short-circuit piston of the rectangular waveguide, it can ensure that the energy coupling of the whole system before and after the plasma excitation reaches a high efficiency, and in the extreme case, it can realize that the microwave can supply energy to the plasma in a traveling wave state.

4. The design scheme adopted in the present invention is suitable for any frequency microwave system.

5. This device can be applied to gas-phase chemical reactions (such as: direct conversion of natural gas to ethylene and acetylene, purification of toxic and harmful industrial waste gases, etc.), chemical vapor deposition (such as the deposition of diamond films, etc.), synthesis and processing of materials (such as metal , plasma synthesis of ceramic particles, plasma cutting of materials, drilling, etc.) and solid waste (such as domestic waste, nuclear waste, etc.) treatment.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the present invention.

FIG. 2 is a schematic diagram of the structural dimensions of each part in FIG. 1 .

FIG. 3 is a schematic diagram of an equivalent circuit of FIG. 1 .

Fig. 4 is a schematic diagram of a relationship curve between microwave energy efficiency and the position of the short-circuit piston and the impedance matching adjustment device.

Detailed ways

The present invention relates to a high-power, high-efficiency microwave plasma excitation device. Figure 1 is a schematic structural diagram of the device, including a tunable coaxial resonant cavity 1 and a rectangular waveguide 2. A shaft conversion device 12, the waveguide/coaxial conversion device 12 is a door twist structure in which the door twist block 121 and the dielectric single wire 122 are buckled up and down, and the waveguide/coaxial conversion device 12 is closely connected with the upper and lower surfaces of the rectangular waveguide 2 respectively , the tunable coaxial resonant cavity 1 is composed of an upper chamber 11, a lower chamber 15 located on the upper and lower sides of the waveguide 2 and coaxial with the waveguide/coaxial conversion device 12, and a waveguide/coaxial conversion device 12. The lower chamber is coaxial with the outer conductor 13 and the inner conductor 14. One end of the inner conductor 14 is inserted into the lower chamber 15, and the other end runs through the dielectric single wire 122, the door twist block 121, and the upper chamber 11 in sequence. A resonant cavity short-circuit piston 111 is provided in the axial direction, a microwave source is provided at one end of the rectangular waveguide 2, and a waveguide short-circuit piston 21 is provided at the other end for impedance matching adjustment.

Fig. 2 is a schematic diagram of structural dimensions of each part in Fig. 1 . Where L1 is the length of the inner conductor 14 inserted in the lower chamber 15, L2 is the distance from the resonant cavity short-circuit piston 111 to the upper surface of the waveguide 2, L3 is the center distance from the waveguide short-circuit piston 21 to the inner conductor 14, and L4 is the dielectric single line 122 Along the axial length of the plasma torch, L5 is the thickness of the door torsion block 121, D0 is the outer diameter of the inner conductor 14, and D1 is the outer diameter of the dielectric single wire 122.

Fig. 3 is the equivalent circuit of the device, that is, the equivalent circuit of the tunable coaxial resonant cavity/waveguide orthogonally coupled plasma torch. Among them, G _r1 is the open-circuit end of the tunable coaxial resonator 1, the radiation conductance surrounded by the circular cut-off waveguide, G _r2 is very small when it is not discharged, and gradually increases after the discharge is enhanced; G _r2 is the radiation conductance to the rear waveguide ; G _p is the plasma conductance after plasma initiation, which increases with plasma enhancement; JX _p is the plasma reactance after plasma initiation, which increases with plasma enhancement; jZ ₀₁ cotβl ₁ is a tunable jZ ₀₂ tanβl ₂ is the reactance at the short-circuit piston end of the resonator; jZ ₀ tanβ _w l ₃ is the reactance of the waveguide short-circuit piston 21 in the waveguide; jX _D is the gate twist structure in the waveguide 2 The reactance presented; Rr is the impedance of the rear waveguide system; the number 3 is the microwave source, the number 4 is the coupling structure of the tunable coaxial resonator, and the number 5 is the coupling structure of the rear waveguide system, and the switch K is closed, indicating that the discharge has been generated. Form and intensify plasma;

The plasma is excited by forming a resonance with a certain quality factor in the tunable coaxial resonator 1, and the plasma is induced at the open end of the tunable coaxial resonator 1, and the resonant frequency of the tunable coaxial resonator 1 can be obtained by resonating The position of cavity short circuit piston 111 is adjusted (changing L3). Before initiating plasma, adjust resonant cavity short circuit piston 111 so that the resonant frequency of tunable coaxial resonant cavity 1 is the same as the frequency of microwave power supply. After plasma is generated, the cavity The resonant frequency will inevitably drift, and the magnitude of the frequency drift is related to the plasma state in the cavity. The resonant frequency of the tunable coaxial resonant cavity 1 is always consistent with the power supply frequency through the resonant cavity short-circuit piston 111 can be tracked in real time according to the state of the plasma. unanimous.

The microwave energy of the tunable coaxial resonant cavity 1 obtains a pick-up electromotive force in the rectangular waveguide 2 through the extended inner conductor that runs through the center of the waveguide 2 and stands on the outer conductor 13, and establishes an induced current on the inner conductor 14, thereby exciting the Power transmission in tunable coaxial resonant cavity 1. In order to realize the isolation of the working gas from the outside air, the dielectric single line 122 is composed of low-loss dielectric material and tunable coaxial resonant cavity. The dielectric single line 122 is a key structural unit of this structural design, and it has the following functions:

(1) undertake the energy coupling from the waveguide to the tunable coaxial resonant cavity 1;

(2) form a tunable coaxial resonant cavity 1 with the upper cavity and the lower cavity;

(3) It can be used for gas sealing.

The size (D1, L4) of the dielectric single line is related to the used microwave frequency (f), the type of dielectric material (ε), and the impedance (Z) design of the tunable coaxial resonator 1. The design principle is to ensure that the dielectric The axial length L4 of the single line along the plasma torch is equal to 0.25n (n=1, 2, 3, ...) times the operating wavelength of the microwave source 3, and the inner diameter of the dielectric single line 122 is the same as the inner conductor of the tunable coaxial resonant cavity 1 14 have the same diameter, the outer diameter D1 is selected to keep the impedance matching that of the tunable coaxial resonator 1, and the degree of coupling between the waveguide and the coaxial system is related to the span of the dielectric single line 122 in the waveguide.

The main function of the door twist block 121 is to control the microwave system to reduce the coupling degree of the rectangular waveguide/tunable coaxial resonator in the cold state, so as to facilitate the establishment of the high electric field strength required for plasma excitation. The door twist block 121 The thickness L5 is selected according to the length of the single dielectric line 122 and the size of the narrow side of the waveguide 2 , and is numerically equal to the size of the narrow side of the waveguide 2 minus the length of the single dielectric line 122 .

The role of the waveguide short-circuit piston 21 is to adjust the impedance matching between the cold state and the hot state (before and after plasma generation) of the system. In the gate-twist structure, the span of the dielectric single line in the rectangular waveguide determines the theoretical coupling amount of the waveguide/coaxial coupling, but because the load impedance of the system changes greatly before and after the plasma is excited, due to the impedance mismatch, the direct Affects the efficiency of waveguide/coaxial coupling. The adjustment of the waveguide short-circuit piston can resist the reactance of the waveguide section after the impedance, so that the impedance before and after the plasma excitation can be optimally matched, so that the microwave energy can be fully coupled to the plasma.

In this structure, changing the position of the waveguide short-circuit piston 21 can change the degree of conversion, which can be used as a method to change the degree of coupling between the waveguide and the coaxial system.

If changing the coupling degree by changing the position of the waveguide short-circuit piston 21 cannot be changed to a smaller coupling degree, the coupling degree can be changed by restricting the span of the dielectric single line.

The working principle of the whole device is as follows: the microwave energy is coupled from the rectangular waveguide 2 transmission system to the tunable coaxial resonator 1 through the waveguide/coaxial conversion device 12, and the cold waveguide/coaxial conversion is reduced by using the appropriate length of the dielectric single line 122 The coupling makes the tunable coaxial resonator 1 form the necessary high-Q resonance state at the initial stage of initiation, accumulates energy, and causes the discharge of the working gas; with the extension and strengthening of the plasma, it is adjusted by the short-circuit piston 111 of the resonator Due to the drift of the resonance frequency caused by the existence of the plasma, the resonance frequency of the tunable coaxial resonator 1 is consistent with the operating frequency of the microwave source 3; the waveguide/coaxial conversion coupling after the plasma generation is adjusted by the waveguide short-circuit piston 21 The degree makes the system gradually switch to the low-Q resonance state, and then switch to the working state of the traveling wave. Through this series of adjustment processes, the excitation and maintenance of high-power and high-efficiency plasma are realized.

1. For microwaves with a working frequency of 2450MHz, when boron nitride is used as the dielectric material in the dielectric single wire, the main dimensions of the plasma torch device are: D ₀ =17mm, D ₁ =57mm, L ₁ =165mm, L ₄ =37mm, L ₅ = 17 mm.

2. For microwaves with a working frequency of 915MHz, when boron nitride is used as the dielectric material in the dielectric single line, the main dimensions of the plasma torch device are: D ₀ =31mm, D ₁ =140mm, L ₁ =650mm, L ₄ =82mm, L ₅ = 42 mm.

3. For microwaves with a working frequency of 2450MHz, when alumina is used as the dielectric material in the dielectric single wire, the main dimensions of the plasma torch device are: D ₀ = 17mm, D ₁ = 35mm, L ₁ = 165mm, L ₄ = 28mm, L ₅ = 27mm.

4. For microwaves with a working frequency of 2450MHz, when polytetrafluoroethylene is used as the dielectric material in the dielectric single wire, the main dimensions of the plasma torch device are: D ₀ =17mm, D ₁ =63mm, L ₁ =165mm, L ₄ =42mm, L ₅ =12 mm.

5. For microwaves with a working frequency of 2450MHz, when the dielectric material in the dielectric single line is quartz, the main dimensions of the plasma torch device are: D ₀ = 17mm, D ₁ = 52mm, L ₁ = 165mm, L ₄ = 40mm, L ₅ = 15mm.

6. After the microwave plasma is excited, the size of _L2 and _L3 is adjusted, and the change of microwave energy coupling efficiency is shown in Figure 4. In the experiment, the microwave incident power is 1000-6000W (4000W in this embodiment), and the working gas medium is Hydrogen, using reflected and incident microwave energy to calculate microwave energy coupling efficiency.

Claims (9)

1. HIGH-POWERED MICROWAVES plasma torch, it is characterized in that: comprise tunable coaxial resonant cavity (1), rectangular waveguide (2), establish waveguide/coaxial conversion equipment (12) in the described rectangular waveguide (2), the structure of twisting together that described waveguide/coaxial conversion equipment (12) turns round for door that piece (121) and medium single line (122) fasten up and down, described waveguide/coaxial conversion equipment (12) closely contacts with rectangular waveguide (2) upper and lower surface respectively and is connected, described tunable coaxial resonant cavity (1) is by being positioned at waveguide (2) both sides and the epicoele (11) coaxial with waveguide/coaxial conversion equipment (12) up and down, cavity of resorption (15), and the common formation of waveguide/coaxial conversion equipment (12), on, cavity of resorption is coaxial with outer conductor (13) and inner wire (14), inner wire (14) one ends are plugged in cavity of resorption (15), the other end runs through medium single line (122) successively, door is turned round piece (121), epicoele (11), be provided with resonant cavity short-circuit plunger (111) along axis direction between the internal and external conductor of epicoele (11), described rectangular waveguide (2) one sides are provided with microwave source, and another side is provided with waveguide short piston (21).

2. according to the described HIGH-POWERED MICROWAVES plasma torch of claim 1, it is characterized in that: described medium single line (122) is made of inner wire (14) and its dielectric on every side, and the DIELECTRIC CONSTANT of dielectric material is less than or equal to 10.

3. according to the described HIGH-POWERED MICROWAVES plasma torch of claim 2, it is characterized in that: described dielectric material is one of air, boron nitride, polytetrafluoroethylene, aluminium oxide, quartz or its complex.

4. according to claim 1 or 2 described HIGH-POWERED MICROWAVES plasma torchs, it is characterized in that: the frequency of described microwave source is 2450MHz, 915MHz or 314MHz.

5. according to the described HIGH-POWERED MICROWAVES plasma torch of claim 4, it is characterized in that: the frequency of described microwave source is 2450MHz, and its medium single line (122) medium material adopts boron nitride, inner wire (14) outer diameter D ₀=4～30mm, medium single line (122) outer diameter D ₁=14～100mm, inner wire (14) is plugged in the length L in the cavity of resorption (15) ₁=30～300mm, medium single line (122) is along the plasmatorch axial length L ₄=20～54.6mm, door is turned round piece (121) thickness L ₅=0～34.6mm.

6. according to the described HIGH-POWERED MICROWAVES plasma torch of claim 4, it is characterized in that: the frequency of described microwave source is 2450MHz, and its medium single line (122) medium material adopts aluminium oxide, inner wire (14) outer diameter D ₀=4～30mm, medium single line (122) outer diameter D ₁=10～60mm, inner wire (14) is plugged in the length L in the cavity of resorption (15) ₁=30～300mm, medium single line (122) is along the plasmatorch axial length L ₄=15～40mm, door is turned round piece (121) thickness L ₅=14～40mm.

7. according to the described HIGH-POWERED MICROWAVES plasma torch of claim 4, it is characterized in that: the frequency of described microwave source is 2450MHz, and its medium single line (122) medium material adopts polytetrafluoroethylene, inner wire (14) outer diameter D ₀=4～30mm, medium single line (122) outer diameter D ₁=18～108mm, inner wire (14) is plugged in the length L in the cavity of resorption (15) ₁=30～300mm, medium single line (122) is along the plasmatorch axial length L ₄=30～54.6mm, door is turned round piece (121) thickness L ₅=0～24.6mm.

8. according to the described HIGH-POWERED MICROWAVES plasma torch of claim 4, it is characterized in that: the frequency of described microwave source is 2450MHz, and its medium single line (122) medium material adopts quartzy, inner wire (14) outer diameter D ₀=4～30mm, medium single line (122) outer diameter D ₁=14～90mm, inner wire (14) is plugged in the length L in the cavity of resorption (15) ₁=30～300mm, medium single line (122) is along the plasmatorch axial length L ₄=25～54.6mm, door is turned round piece (121) thickness L ₅=0～30mm.

9. according to the described HIGH-POWERED MICROWAVES plasma torch of claim 4, it is characterized in that: the frequency of described microwave source is 915MHz, and its medium single line (122) medium material adopts boron nitride, inner wire (14) outer diameter D ₀=12～50mm, medium single line (122) outer diameter D ₁=60～220mm, inner wire (14) is plugged in the length L in the cavity of resorption (15) ₁=100～1200mm, medium single line (122) is along the plasmatorch axial length L ₄=40～124mm, door is turned round piece (121) thickness L ₅=0～84mm.

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