Magnetized atmospheric pressure pulse microwave plasma jet discharger

Abstract

The invention belongs to the technical field of microwave plasmas, and particularly relates to a magnetized atmospheric pressure pulse microwave plasma jet discharger. The discharger is reasonable in design, microwave energy is fed into the discharge chamber through the SMA interface, high electric field intensity is formed at the tip of the hollow needle electrode, and fed working gas is disrupted and discharged; a magnet exciting coil outside the quartz tube generates an axial magnetic field inside the quartz tube through direct current, electrons do spiral cycloid motion in an electromagnetic field, and electron cyclotron resonance can be achieved under the field. Through magnetic field constraint, high-energy electrons are constrained in a core area, a motion path is prolonged, effective collision times are increased, gas dissociation efficiency and ionization degree are improved, and collision loss of the electrons and a wall surface is reduced; the plasma jet performance is improved; the device works in an atmospheric pressure environment, does not need a vacuum system, reduces equipment cost and maintenance difficulty, reduces electrode sputtering and cavity corrosion, and prolongs the service life of core components.

Description

Technical Field

[0001] The invention belongs to the technical field of microwave plasma, and in particular relates to a magnetized atmospheric pressure pulse microwave plasma jet discharger. Background Art

[0002] Atmospheric pressure microwave plasma jet is a low-temperature plasma technology excited by microwave energy under normal pressure environment. It uses microwaves (usually 2.45GHz or 915MHz) to generate a high-frequency electric field in the resonant cavity to ionize the working gas (such as argon, helium or air, etc.) to form a stable plasma jet. This plasma jet has the characteristics of high active particle density (such as free radicals, excited atoms) and close to room temperature, and is suitable for material modification, biomedicine, environmental purification and other fields. Its advantages include: no need for a vacuum low-pressure system and simple equipment structure; microwave energy is directly coupled to electrons, with high energy efficiency; plasma jets are highly controllable and can act precisely on the target surface. Typical applications include nanomaterial synthesis, wound disinfection, pollutant degradation, etc., and it is a research hotspot in fields such as green chemistry. After searching:

[0003] The document "A Microwave Atmospheric Pressure Plasma Jet Device Based on a Rectangular Coaxial Structure" ([J]. Vacuum Electronics Technology, 2024, (05): 107-111.) introduces a portable atmospheric pressure microwave plasma jet source based on a rectangular coaxial structure design and operating at 2.45GHz. The region of uniform electric field between the inner and outer conductors of the device is rectangular, which is beneficial for increasing the discharge width of the plasma, having greater power capacity, and a simple device structure. However, when the device is exposed to open space, the high-energy particles in the argon plasma will frequently collide with nitrogen and oxygen molecules in the air, resulting in a decrease in electron energy, a more complex trajectory of electrons in space, and a broadening of the electron energy distribution function toward the low-energy direction.

[0004] The paper "Microwave-excited atmospheric-pressure microplasmas based on acoaxial transmission line resonator" ([J]. Plasma Sources Science and Technology, 2009, 18(2):025029.) describes a 2.45 GHz coaxial transmission line resonator that can achieve self-sustaining discharge. This device has advantages such as reduced heat generation, no electrode corrosion, and low maintenance costs. However, the device lacks a gas flow channel, and electrons diffuse after leaving the excitation region due to lack of confinement, resulting in energy dispersion. This diffusion reduces the energy density and spatial stability of the plasma jet.

[0005] In recent years, magnetic field-assisted plasma discharge technology has shown broad application prospects due to its unique control capabilities. In particular, the magnetic field-assisted discharge mode provides an innovative technical approach to achieve efficient and stable atmospheric pressure plasma jets.

[0006] Chinese patent publication CN110996488A discloses a medical plasma jet device. This device offers advantages such as controllable plasma jet intensity. However, the device utilizes dielectric barrier discharge, where some of the input energy is absorbed by the dielectric layer, resulting in low energy utilization. Furthermore, the discharge is composed of irregular filaments, which can lead to uneven treatment. Under prolonged high pressure, the dielectric layer may experience localized breakdown. The device has two sets of energized coils, making coordinated magnetic field control difficult, requiring more precise control and matching to achieve the desired plasma jet intensity.

[0007] The document "Research and Application of Electron Cyclotron Resonance (ECR) Plasma" ([J]. Progress in Physics, 1992, (01): 38-62.) introduces a microwave (2.45GHz) electron cyclotron resonance discharge under low pressure. The disadvantage of this method is that the low-temperature plasma is generated under low-pressure conditions, but the low-pressure environment requires expensive vacuum equipment; in addition, the object to be processed must also be able to withstand low pressure, which seriously limits the application range of low-temperature plasma.

[0008] In view of this, the inventors hope to design a plasma jet device that can achieve efficient and stable discharge, low loss, high ionization rate and high energy utilization under atmospheric pressure environment. Summary of the Invention

[0009] The present invention aims to overcome the aforementioned problems of conventional technologies by providing a magnetized atmospheric pressure pulsed microwave plasma jet discharger capable of generating a low-temperature, high-electron-temperature, and highly active plasma under atmospheric pressure. Furthermore, by regulating the motion of electrons in the plasma excitation region through a magnetic field, the discharger can increase the electron path length, raise the electron temperature, improve the ionization degree of the working gas, and enhance the stability of the plasma jet.

[0010] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0011] The present invention provides a magnetized atmospheric pressure pulsed microwave plasma jet discharger, comprising:

[0012] A gas input unit, the gas input unit being used to introduce working gas;

[0013] A length adjustment unit, wherein the length adjustment unit is used to adjust the extended length of the hollow needle electrode so as to form a resonance match with the microwave wavelength;

[0014] a microwave energy input unit, wherein the microwave energy input unit is used to couple microwave energy into the tapered resonator;

[0015] A resonant discharge unit, the resonant discharge unit being used to form a high electric field excitation region in the quartz tube;

[0016] A magnetic field control unit, which generates an axial magnetic field through a DC regulated current power supply to constrain the electron motion trajectory;

[0017] A cooling water circulation unit utilizes a cooling water-based circulating cooling system to reduce the temperature of the excitation coil during operation.

[0018] Furthermore, in the above-mentioned magnetized atmospheric pressure pulsed microwave plasma jet discharger, the gas input unit includes a first gas inlet for introducing a working gas, a second gas inlet for introducing a working gas, and a third gas inlet for introducing a working gas, and the working gas is argon, helium or air.

[0019] Furthermore, in the above-mentioned magnetized atmospheric pressure pulsed microwave plasma jet discharger, the length adjustment unit includes a length adjustment knob, and the length adjustment knob adjusts the extension length of the hollow needle electrode through threaded transmission.

[0020] Furthermore, in the above-mentioned magnetized atmospheric pressure pulsed microwave plasma jet discharger, the microwave energy input unit includes an SMA interface, one end of the SMA interface is in contact with the hollow needle electrode, and the other end is connected to the microwave power supply through a coaxial radio frequency line; the hollow needle electrode is a hollow tubular structure, one end of which is connected to the air inlet as a gas flow channel, and the other end is a tip. When the tip position matches the microwave resonance point, the strongest electric field strength can be formed.

[0021] Furthermore, in the above-mentioned magnetized atmospheric pressure pulsed microwave plasma jet discharger, the resonant discharge unit includes a quartz tube, a hollow needle electrode, a gradient resonator and a rubber ring. The hollow needle electrode passes through the interior of the gradient resonator, and its tip extends into the quartz tube to form a high electric field excitation region; the quartz tube is a high-purity quartz glass cavity, which is the plasma generation region; the quartz tube rubber ring is embedded in the bottom of the gradient resonator and is used to fix the quartz tube.

[0022] Furthermore, in the above-mentioned magnetized atmospheric pressure pulsed microwave plasma jet discharger, the outer diameter of the quartz tube is 8 mm, the inner diameter is 6 mm, and the length is 35 mm.

[0023] Furthermore, in the above-mentioned magnetized atmospheric pressure pulsed microwave plasma jet discharger, the gradient resonator is a gradient deformation structure, which can generate a higher electric field intensity than the abrupt structure, and is conducive to breakdown gas discharge.

[0024] Furthermore, in the above-mentioned magnetized atmospheric pressure pulsed microwave plasma jet discharger, the magnetic field control unit includes an excitation coil, which is fixed to the outside of the quartz tube and is powered by a DC regulated current power supply to generate an axial magnetic field with a magnetic field intensity range of 0.07 to 0.09T.

[0025] Furthermore, in the above-mentioned magnetized atmospheric pressure pulsed microwave plasma jet discharger, the excitation coil is wound by enameled wire, with 8 turns, a coil diameter of 10.5 mm, a wire diameter of 0.5 mm, and a coil length of 8 mm. When the current is 6 A, an axial magnetic field of 0.0875 T can be generated to achieve electron cyclotron resonance.

[0026] Furthermore, in the above-mentioned magnetized atmospheric pressure pulsed microwave plasma jet discharger, the working gas is ionized under the synergistic effect of microwave energy and magnetic field, and the electrons perform spiral cycloid motion in the orthogonal electromagnetic field, the motion path is extended, and the collision frequency is increased, thereby improving the gas ionization degree and plasma jet stability.

[0027] The working principle of the present invention is as follows:

[0028] In a coaxial resonator-driven plasma jet device, the excitation zone (i.e., the primary region of plasma generation) is typically concentrated near the tip of the inner conductor electrode. To further manipulate the plasma's characteristics, an excitation coil is added outside the excitation zone (i.e., outside the quartz tube) and fed with a direct current. The resulting magnetic field constrains electron motion, thereby optimizing the stability and spatial distribution of the plasma jet.

[0029] Driven by microwave power, the magnetized atmospheric pressure pulsed microwave plasma jet discharger feeds 2.45 GHz microwave energy into the discharge chamber via an SMA interface, generating a high electric field intensity at the tip of the needle electrode at its open end. Gas is injected into the discharge chamber through an inlet port. Under the action of the microwave energy, the gas reaches its breakdown threshold, causing a breakdown and discharge. Electrons generated by the gas discharge travel to the electron cyclotron resonance (ECR) region (B = 0.0875T), where their cyclotron frequency is equal to the microwave frequency. Under the influence of the microwave's high-frequency electric field, the electrons resonate and collide with the gas to generate ECR plasma, maximizing microwave energy absorption and breaking down the gas, thereby increasing the gas ionization degree.

[0030] During gas discharge, the electric field accelerates the movement of electrons. When both an electric field and an external magnetic field exist in the discharge system, the dynamic characteristics of the electrons will undergo essential changes. The movement of electrons in an orthogonal electromagnetic field shows a typical spiral cycloid trajectory. The electric field continuously accelerates the electrons, while the Lorentz force of the magnetic field (F = qv × B) deflects the direction of electron movement. This combined effect results in: a significant increase in the electron movement path, an increase in the frequency of collisions with gas molecules, an improvement in ionization efficiency, and an expansion of the discharge area. By precisely controlling the electromagnetic field parameters and their spatiotemporal distribution, active regulation of the discharge characteristics can be achieved to meet the plasma parameter requirements of different application scenarios.

[0031] In 2.45GHz microwave discharge, a 0.0875T magnetic field can achieve ECR discharge. Even if electrons collide frequently with gas molecules under atmospheric pressure and the magnetic field does not reach exactly 0.0875T, the magnetic field will still cause the electrons to move along a spiral trajectory to extend their path, and will significantly increase the proportion of high-energy electrons in the electron energy distribution function. This significantly enhances the gas collision ionization efficiency, thereby expanding the discharge area and increasing the discharge intensity. Therefore, by applying a suitable external magnetic field configuration, the discharge mode of the microwave plasma jet can be controlled, the ionization degree of the discharge gas molecules can be increased, and more energy can be used to maintain the discharge.

[0032] The beneficial effects of the present invention are:

[0033] 1. Compared with existing technologies, this device incorporates an excitation coil to generate an external magnetic field. Under the influence of the magnetic field, high-energy electrons, due to their larger gyrotron radius, are effectively confined to the core of the discharge, significantly extending their motion path and increasing the number of effective collisions with the reactant gas. Low-energy electrons, however, due to their smaller gyrotron radius, are trapped by the strong magnetic field near the magnetic field lines, reducing random inelastic collisions with air molecules. The Lorentz force regulates the motion trajectories of charged particles in the plasma, further streamlining the electron trajectory. High-energy electrons confined by the magnetic field efficiently collide with reactive groups to promote the dissociation of gas molecules, significantly improving the plasma's dissociation efficiency and gas ionization degree. Furthermore, the magnetic field confinement effect significantly increases the relative proportion of the electron energy distribution function in the high-energy region. Furthermore, magnetic field confinement reduces electron losses from collisions with walls, freeing up more energy for ionization.

[0034] 2. Compared with existing technologies, this device significantly improves plasma jet performance through magnetic field confinement. The magnetic field confinement effect increases the length and diameter of the plasma jet and controls its stability, significantly outperforming conventional atmospheric pressure plasma jets. Furthermore, the magnetic field's effective suppression of electron diffusion increases the density of active particles, significantly enhancing the plasma's reactivity.

[0035] 3. Compared with existing technologies, this device operates at atmospheric pressure, eliminating the need for complex vacuum or low-pressure systems, significantly reducing equipment costs and maintenance. Furthermore, it can directly process materials at atmospheric pressure, improving process applicability. Furthermore, the Lorentz force generated by the 0.0875T axial magnetic field constrains electron motion, reducing the bombardment of high-energy electrons on the electrodes, reducing electrode sputtering and cavity corrosion, and extending the service life of core components (such as the needle electrode and quartz tube). This design significantly improves the practicality and cost-effectiveness of the device while maintaining plasma properties.

[0036] Of course, any product implementing the present invention does not necessarily need to achieve all of the above advantages at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 A schematic structural diagram of the present invention from one perspective;

[0039] Figure 2 It is a structural schematic diagram of the present invention from another angle;

[0040] Figure 3 Schematic diagram of the internal structure of the present invention as a whole;

[0041] Figure 4 This is a schematic diagram of the assembly of the length adjustment knob, SMA interface, and hollow needle electrode in the present invention;

[0042] Figure 5 Schematic diagram of the installation positions of the second air inlet and the third air inlet in the present invention;

[0043] Figure 6 Schematic diagram of the installation position of the first air inlet in the present invention;

[0044] Figure 7 Schematic diagram of the structure of the gradient resonator in the present invention;

[0045] Figure 8 Schematic diagram of the structure of the hollow needle electrode in the present invention;

[0046] In the accompanying drawings, the reference numerals of the various components are as follows:

[0047] 1-First air inlet, 2-Second air inlet, 3-Third air inlet, 4-Length adjustment knob, 5-SMA interface, 6-Excitation coil, 7-Quartz tube, 8-Hollow needle electrode, 9-Gradual resonator, 10-Rubber ring, 11-Circulating cooling system. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] like Figures 1-8 As shown, this embodiment provides a magnetized atmospheric pressure pulsed microwave plasma jet discharger, which includes a first air inlet 1, a second air inlet 2, a third air inlet 3, a length adjustment knob 4, an SMA interface 5, an excitation coil 6, a quartz tube 7, a hollow needle electrode 8, a gradient resonator 9, a rubber ring 10, and a circulating cooling system 11. These components are connected through threads, brackets, and other means to form a complete assembly system from microwave energy input and carrier gas introduction to resonant discharge, magnetic field assistance, and quartz tube fixation, ensuring stable operation of the coaxial resonator and achieving plasma generation.

[0050] In this embodiment, the first, second, and third air inlets 1, 2, and 3 serve as inlets for the working gas, which can be argon, helium, or air. These inlets are threadedly connected to corresponding ports on the resonator body for the working gas. This threaded connection ensures a tight and secure gas passage. The threads of the first inlet 1 mate with the threads above the length adjustment knob 4. The second and third inlets 2, 3 are also threadedly connected to corresponding side ports on the resonator body.

[0051] In this embodiment, the length adjustment knob 4 is connected to the upper thread of the resonator body through a thread; the length adjustment knob 4 adjusts the extension length of the hollow needle electrode 8 through thread transmission.

[0052] In this embodiment, the upper part of the resonator body is connected with the lower part of the resonator body through a thread; the hollow needle electrode 8 is inserted into the interior of the resonator body, and the upper thread of the hollow needle electrode is connected with the inner thread of the length adjustment knob 4. By rotating the knob, the length of the inner conductor electrode is accurately adjusted with the help of thread transmission to meet the resonance matching requirements.

[0053] In this embodiment, the SMA connector 5 is assembled on the side of the resonator body via four threaded ports. One end of the connector contacts the hollow needle electrode 8, coupling microwave energy, while the other end connects to the microwave power supply via a coaxial RF cable. The SMA connector 5 primarily couples the microwave energy generated by the microwave power supply into the discharger. This microwave energy generates a high-frequency microwave electric field within the resonant cavity. The high electric field intensity induced at the tip of the hollow needle electrode 8 reaches the breakdown threshold of the gas, ionizing the gas to produce plasma.

[0054] In this embodiment, two rubber rings 10 are embedded in the bottom of the resonator body. After the quartz tube 7 is inserted into the bottom of the resonator body, the position of the quartz tube is fixed by the two rubber rings 10 to prevent shaking.

[0055] In this embodiment, the gradient resonator 9 makes the electric field intensity of the discharger higher than that of the abrupt discharger, and the discharge phenomenon is more likely to occur.

[0056] In this embodiment, one end of the hollow needle electrode 8 allows for discharge gas flow, while the other end forms a pointed tip. The hollow region of the hollow needle electrode 8 serves as a gas flow channel. When the internal needle electrode length resonates with the wavelength of microwaves of a specific frequency, the tip of the internal needle electrode is at a resonant point, where the electric field intensity is strongest, which is more conducive to plasma discharge.

[0057] In this embodiment, the excitation coil 6 is fixed to the resonator body via an insulating bracket and placed outside the quartz tube 7. A cooling water circulating cooling system 11 is in contact with the excitation coil 6, circulating the cooling water to reduce the temperature of the excitation coil 6 during operation. The excitation coil 6 generates a magnetic field directed along the device axis. The additional coil has a maximum number of turns of 8, with a current of 6A. The solenoid coil diameter is 10.5mm, the coil diameter is 0.5mm, and the coil length is 8mm. The generated magnetic field ranges from 0.07 to 0.09T. The excitation coil 6 is an electromagnetic coil wound with multiple turns of enameled wire and connected to a DC current-stabilized power supply. It is used to generate the 0.0875T magnetic field required for ECR plasma, enabling the regulation of the magnetic field strength. This allows the charged particles in the plasma to be subjected to the Lorentz force, increasing the probability of collisions between electrons and gas molecules, thereby increasing the impact ionization rate of the gas.

[0058] In this embodiment, the quartz tube 7 is a cavity formed of high-purity (purity greater than 99.99%) quartz glass; the quartz tube 7 is the plasma generation zone; the quartz tube 7 has an outer diameter of 8 mm, an inner diameter of 6 mm, and a length of 35 mm; the purpose of placing the quartz tube 7 is to prevent the inner and outer electrodes from breaking through the air and generating an arc due to excessive electric field strength.

[0059] In this embodiment, the circulating cooling system 11 based on cooling water is used to reduce the temperature of the excitation coil 6 during operation. By circulating the cooling water, the heat generation of the coil is reduced, and the normal operation of the discharger is maintained.

[0060] A specific application of this embodiment is as follows: during operation, the operating frequency of the microwave signal source is first set to 2.45 GHz, the output frequency of the pulse modulation signal is set to 20 kHz and the duty cycle is set to 0.4, the peak input power is set to 60 W, argon gas is introduced, and the gas flow rate is 0.25 slm; the number of turns of the additional coil is set to 8 turns, and the current is 6 A; the diameter of the solenoid coil is 10.5 mm, the coil diameter is 0.5 mm, and the spacing between each turn of the coil is 0.5 mm; the inductance of the coil is 0.546 μH, the applied magnetic field is 0.0875 T, and the direction of the magnetic field is the axial direction of the device; argon gas enters the discharge chamber through the air inlet 1 The SMA interface 5 couples the microwave energy generated by the microwave power supply into the discharger. The microwave energy generates a high-frequency microwave electric field within the gradient resonant cavity 9. The tip of the hollow needle electrode 8 induces a high electric field intensity, reaching the breakdown threshold of the argon gas, thereby ionizing the argon gas in the quartz tube 7 to produce plasma. The quartz tube 7 has an outer diameter of 8 mm, an inner diameter of 6 mm, and a length of 35 mm. One end of the quartz tube 7 is fixed to the discharger by a rubber ring 10, and the other end is an outlet. The excitation coil 6 is placed outside the quartz tube 7, wound with multiple turns, and connected to a DC current-stabilized power supply to generate an axial magnetic field, which constrains the movement of charged particles in the atmospheric pressure plasma jet. The circulating cooling system 11 is used to reduce the temperature of the excitation coil 6 during operation. By circulating cooling water, the heat generated by the coil is reduced, maintaining the normal operation of the discharger.

[0061] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A magnetized atmospheric pressure pulsed microwave plasma jet discharger, characterized in that: include: A gas input unit, the gas input unit being used to introduce working gas; A length adjustment unit, wherein the length adjustment unit is used to adjust the extended length of the hollow needle electrode so as to form a resonance match with the microwave wavelength; a microwave energy input unit, wherein the microwave energy input unit is used to couple microwave energy into the tapered resonator; A resonant discharge unit, the resonant discharge unit being used to form a high electric field excitation region in the quartz tube; A magnetic field control unit, which generates an axial magnetic field through a DC regulated current power supply to constrain the electron motion trajectory; A cooling water circulation unit utilizes a cooling water-based circulating cooling system to reduce the temperature of the excitation coil during operation.

2. The magnetized atmospheric pressure pulsed microwave plasma jet discharger according to claim 1, characterized in that: The gas input unit includes a first gas inlet for introducing a working gas, a second gas inlet for introducing a working gas, and a third gas inlet for introducing a working gas. The working gas is argon, helium, or air.

3. The magnetized atmospheric pressure pulsed microwave plasma jet discharger according to claim 1, characterized in that: The length adjustment unit includes a length adjustment knob, and the length adjustment knob adjusts the extension length of the hollow needle electrode through thread transmission.

4. The magnetized atmospheric pressure pulsed microwave plasma jet discharger according to claim 1, characterized in that: The microwave energy input unit includes an SMA interface, one end of which contacts the hollow needle electrode, and the other end is connected to the microwave power supply through a coaxial radio frequency line; The hollow needle electrode is a hollow tubular structure, one end of which is connected to the air inlet as a gas flow channel, and the other end is a tip. When the tip position matches the microwave resonance point, the strongest electric field intensity can be formed.

5. The magnetized atmospheric pressure pulsed microwave plasma jet discharger according to claim 1, characterized in that: The resonant discharge unit includes a quartz tube, a hollow needle electrode, a gradient resonator, and a rubber ring. The hollow needle electrode passes through the gradient resonator, and its tip extends into the quartz tube to form a high electric field excitation area. The quartz tube is a high-purity quartz glass cavity, which is the plasma generation area. The quartz tube rubber ring is embedded in the bottom of the gradient resonator and is used to fix the quartz tube.

6. The magnetized atmospheric pressure pulsed microwave plasma jet discharger according to claim 5, characterized in that: The quartz tube has an outer diameter of 8 mm, an inner diameter of 6 mm, and a length of 35 mm.

7. The magnetized atmospheric pressure pulsed microwave plasma jet discharger according to claim 5, characterized in that: The gradient resonator has a gradient structure, which can generate a higher electric field intensity than a sudden change structure, and is conducive to breakdown gas discharge.

8. The magnetized atmospheric pressure pulsed microwave plasma jet discharger according to claim 1, characterized in that: The magnetic field control unit includes an excitation coil, which is fixed on the outside of the quartz tube and generates an axial magnetic field through a DC regulated current power supply. The magnetic field intensity ranges from 0.07 to 0.09T.

9. The magnetized atmospheric pressure pulsed microwave plasma jet discharger according to claim 8, characterized in that: The excitation coil is wound with enameled wire, with 8 turns, a coil diameter of 10.5 mm, a wire diameter of 0.5 mm, and a coil length of 8 mm. When a current of 6 A is passed through it, an axial magnetic field of 0.0875 T can be generated to achieve electron cyclotron resonance.

10. The magnetized atmospheric pressure pulsed microwave plasma jet discharger according to claim 1, characterized in that: The working gas is ionized under the synergistic effect of microwave energy and magnetic field, and the electrons perform spiral cycloid motion in the orthogonal electromagnetic field, the motion path is extended, the collision frequency is increased, and the gas ionization degree and plasma jet stability are improved.

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