Plasma generating device and method

Abstract

The present invention provides a plasma generating device and method, wherein the plasma generating device at least comprises: a coaxial line resonator having an open end; a waveguide resonator having at least two openings, which is conductively connected to the coaxial line resonator, and the open end of the coaxial line resonator is butted with an opening of the waveguide resonator, so that electromagnetic waves can oscillate simultaneously in the coaxial line resonator and the waveguide resonator. The plasma generating device of the present invention is designed in combination with the coaxial line resonator and the waveguide resonator, and the open end of the coaxial line resonator is butted with an opening of the waveguide resonator, so that electromagnetic waves can oscillate simultaneously in the coaxial line resonator and the waveguide resonator, thereby strengthening the oscillation effect of the electromagnetic waves, strengthening the electromagnetic waves leaving the surface of the coaxial line, strengthening its coupling effect on the plasma, and enhancing its ability to resist water vapor interference.

Description

Technical Field

[0001] The present invention relates to the field of optical spectrum and mass spectrum technology, and in particular to a plasma generating device and method. Background Art

[0002] Plasma is a state of matter. It is widely used in spectroscopy, mass spectrometry and other technologies because of the physical processes such as dissociation, ionization and transition that can react to the components of matter. Microwave plasma is a branch of plasma technology. Some researchers have disclosed its design methods. Currently, there are three main related technical solutions: plasma generation device based on microstrip line resonator, plasma maintenance device based on waveguide resonator, and plasma generation device based on coaxial line resonator.

[0003] However, the resonator structures and electromagnetic field distributions in these three types of plasma generation devices are different, which will produce plasmas with greatly different properties. Among them, devices based on microstrip line resonators and waveguide resonators can achieve better coupling between electromagnetic fields and plasmas with the help of the spatial electromagnetic field formed by the waveguide, and are currently relatively mature; however, in some occasions, it is preferred to use devices based on coaxial line resonators, and the electromagnetic field of the coaxial line resonator will decay rapidly when it leaves the surface of the coaxial line, and its coupling effect on the plasma is weak. The plasma generated by this type of equipment often has the characteristics of difficulty in resisting water vapor interference, and the actual effect is biased. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a microwave plasma generation technical solution for solving the above-mentioned technical problems.

[0005] To achieve the above-mentioned purpose and other related purposes, the technical solution provided by the present invention is as follows.

[0006] A plasma generating device, comprising at least:

[0007] A coaxial line resonator having an open end;

[0008] The waveguide resonator has at least two openings and is conductively connected to the coaxial line resonator, and the open end of the coaxial line resonator is butted against an opening of the waveguide resonator, so that electromagnetic waves can oscillate simultaneously in the coaxial line resonator and the waveguide resonator.

[0009] Optionally, the plasma generating device further comprises a microwave coupling device, and the microwave coupling device is arranged in the coaxial line resonator to generate the electromagnetic wave.

[0010] Optionally, the coaxial line resonator includes a first-caliber closed-loop conductive wall surface, a second-caliber closed-loop conductive wall surface, and a third-caliber closed-loop conductive wall surface, which are sleeved on the same central axis from outside to inside, the inner diameter of the first-caliber closed-loop conductive wall surface is larger than the inner diameter of the second-caliber closed-loop conductive wall surface, and the inner diameter of the second-caliber closed-loop conductive wall surface is larger than the inner diameter of the third-caliber closed-loop conductive wall surface; and the first-caliber closed-loop conductive wall surface, the second-caliber closed-loop conductive wall surface, and the third-caliber closed-loop conductive wall surface are flushly arranged at one end along the central axis direction, and the corresponding end is an open circuit of the coaxial line resonator. end; the coaxial line resonator also includes a bottom conductive wall radially arranged along the second caliber closed-loop conductive wall, and the bottom conductive wall is arranged along the direction of the central axis away from the open end of the coaxial line resonator, the bottom conductive wall includes a first bottom conductive wall and a second bottom conductive wall, one end of the first bottom conductive wall is connected to the first caliber closed-loop conductive wall, and the other end is connected to the second caliber closed-loop conductive wall, one end of the second bottom conductive wall is connected to the second caliber closed-loop conductive wall, and the other end is connected to the third caliber closed-loop conductive wall.

[0011] Optionally, a first opening is provided on the first-caliber closed-loop conductive wall surface, and the first opening is used to accommodate the microwave coupling device.

[0012] Optionally, the inner conductor of the microwave coupling device passes through the first opening and is radially inserted into the area between the first-caliber closed-loop conductive wall surface and the second-caliber closed-loop conductive wall surface, and the inner conductor of the microwave coupling device does not contact the second-caliber closed-loop conductive wall surface, so as to generate the electromagnetic wave by electric field coupling.

[0013] Optionally, the inner conductor of the microwave coupling device passes through the first opening and is radially inserted into the area between the first-caliber closed-loop conductive wall surface and the second-caliber closed-loop conductive wall surface, and the inner conductor of the microwave coupling device is in ohmic contact with the second-caliber closed-loop conductive wall surface to generate the electromagnetic wave through magnetic field coupling.

[0014] Optionally, the bottom conductive wall also includes a third bottom conductive wall, which is arranged on the other end of the second caliber closed-loop conductive wall opposite to the open end, one end of the third bottom conductive wall is connected to the second caliber closed-loop conductive wall, and the other end is connected to the third caliber closed-loop conductive wall; a second opening is also provided on the area of ​​the second caliber closed-loop conductive wall close to the third bottom conductive wall, and the second opening is connected to an external airflow duct; a plurality of third openings are provided on the second bottom conductive wall.

[0015] Optionally, the waveguide resonator includes a closed conductive space, the closed conductive space has at least a first opening and a second opening, the first opening is arranged opposite to the second opening, and the first opening and the second opening are respectively arranged on the same central axis as the closed conductive space; the first opening is connected to the open end so that electromagnetic waves can oscillate simultaneously in the coaxial line resonator and the waveguide resonator.

[0016] Optionally, the third-caliber closed-loop conductive wall surface includes a hollow structure, and the hollow structure is arranged coaxially with the first opening to accommodate a sample introduction pipe; the tip of the sample introduction pipe is arranged flush with the open end.

[0017] Optionally, a quartz pipe is provided on the side wall of the gap between the second caliber closed-loop conductive wall surface and the third caliber closed-loop conductive wall surface.

[0018] Optionally, a first heat dissipation hole is provided on the first bottom conductive wall, and a second heat dissipation hole is provided on the waveguide resonator.

[0019] Optionally, in the coaxial line resonator, the electric field at the open end is the strongest; and the waveguide resonator operates in TM010 mode.

[0020] A plasma generating method, comprising:

[0021] Generate electromagnetic waves through a coaxial line resonator;

[0022] Introducing the electromagnetic wave into a waveguide resonator to cause the waveguide resonator to oscillate and strengthen the electromagnetic wave;

[0023] A maintenance gas is introduced, and the maintenance gas is excited by the enhanced electromagnetic wave to generate plasma.

[0024] As described above, the plasma generating device and method provided by the present invention have at least the following beneficial effects:

[0025] The design is combined with a coaxial line resonator and a waveguide resonator. The open end of the coaxial line resonator is connected to an opening of the waveguide resonator, so that the electromagnetic wave can oscillate in the coaxial line resonator and the waveguide resonator at the same time, thereby strengthening the oscillation effect of the electromagnetic wave, enhancing the electromagnetic wave leaving the surface of the coaxial line, strengthening its coupling effect on the plasma, and enhancing its ability to resist water vapor interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of a plasma generating device in one embodiment of the present invention.

[0027] Figure 2 4 is a cross-sectional view of the structure of a plasma generating device in one embodiment of the present invention.

[0028] Figure 3 FIG. 4 is a structural cross-sectional view of a plasma generating device in another embodiment of the present invention.

[0029] Description of Figure Numbers

[0030] 1—coaxial line resonator, 2—waveguide resonator, 3—microwave coupling device, 4—sample introduction pipe, 5—quartz pipe, 11—first caliber closed-loop conductive wall, 12—second caliber closed-loop conductive wall, 13—third caliber closed-loop conductive wall, 14—bottom conductive wall, 141—first bottom conductive wall, 142—second bottom conductive wall, 143—third bottom conductive wall, 31—inner conductor of microwave coupling device 3, 1A—first opening, 2A—second opening, 1B—first opening, 2B—second opening, 3B—third opening. DETAILED DESCRIPTION

[0031] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0032] See also Figures 1 to 3 . It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner, so the illustrations only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in actual implementation can be changed arbitrarily, and the component layout type may also be more complex. The structure, proportion, size, etc. illustrated in the illustrations attached to this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, it has no technical substantive significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effect that the present invention can produce and the purpose that can be achieved.

[0033] like Figure 1 and Figure 3 As shown, the present invention provides a plasma generating device, which at least comprises:

[0034] A coaxial line resonator 1 having an open end;

[0035] The waveguide resonator 2 has at least two openings and is conductively connected to the coaxial line resonator 1 , and the open end of the coaxial line resonator 1 is butted against an opening of the waveguide resonator 2 , so that electromagnetic waves can oscillate in the coaxial line resonator 1 and the waveguide resonator 2 simultaneously.

[0036] In detail, Figure 2 As shown, the coaxial line resonator 1 includes a first-caliber closed-loop conductive wall surface 11, a second-caliber closed-loop conductive wall surface 12, and a third-caliber closed-loop conductive wall surface 13 which are sleeved on the central axis from outside to inside, the inner diameter of the first-caliber closed-loop conductive wall surface 11 is larger than the inner diameter of the second-caliber closed-loop conductive wall surface 12, and the inner diameter of the second-caliber closed-loop conductive wall surface 12 is larger than the inner diameter of the third-caliber closed-loop conductive wall surface 13; and the first-caliber closed-loop conductive wall surface 11, the second-caliber closed-loop conductive wall surface 12, and the third-caliber closed-loop conductive wall surface 13 are flushly arranged at one end along the central axis direction (the end close to the waveguide resonator 2), and the corresponding end is the coaxial line resonator. 2; the coaxial line resonator 2 also includes a bottom conductive wall 14 radially arranged along the second caliber closed-loop conductive wall 12, and the bottom conductive wall 14 is arranged along the direction of the central axis away from the open end of the coaxial line resonator 1, the bottom conductive wall 14 includes a first bottom conductive wall 141 and a second bottom conductive wall 142, one end of the first bottom conductive wall 141 is connected to the first caliber closed-loop conductive wall 11, and the other end is connected to the second caliber closed-loop conductive wall 12, one end of the second bottom conductive wall 142 is connected to the second caliber closed-loop conductive wall 12, and the other end is connected to the third caliber closed-loop conductive wall 13.

[0037] In detail, Figure 1 and Figure 2 As shown, the plasma generating device further comprises a microwave coupling device 3, which is arranged in the coaxial line resonator 1 to generate electromagnetic waves (generally TEM waves).

[0038] In more detail, Figure 1 and Figure 2 As shown, a first opening 1A is provided on the first-caliber closed-loop conductive wall 11, and the first opening 1A is used to accommodate the microwave coupling device 3. The microwave coupling device 3 needs to induce electromagnetic waves in the coaxial resonator 1, usually in two ways: electric field coupling and magnetic field coupling.

[0039] Based on electric field coupling, such as Figure 2 As shown, the inner conductor 31 of the microwave coupling device 3 passes through the first opening 1A and is radially inserted into the area between the first-caliber closed-loop conductive wall 11 and the second-caliber closed-loop conductive wall 12, and the inner conductor 31 of the microwave coupling device 3 does not contact the second-caliber closed-loop conductive wall 12 to generate electromagnetic waves through electric field coupling.

[0040] Based on magnetic field coupling, such as Figure 3 As shown, the inner conductor 31 of the microwave coupling device 3 passes through the first opening 1A and is radially inserted into the area between the first-caliber closed-loop conductive wall 11 and the second-caliber closed-loop conductive wall 12, and the inner conductor 31 of the microwave coupling device 3 is in ohmic contact with the second-caliber closed-loop conductive wall 12 to generate electromagnetic waves through magnetic field coupling.

[0041] In detail, Figure 1-Figure 3 As shown, the waveguide resonator 2 includes a closed conductive space, which has at least a first opening 1B and a second opening 2B. The first opening 1B and the second opening 2B are arranged opposite to each other, and the first opening 1B and the second opening 2B are respectively arranged coaxially with the closed conductive space; the first opening 1B is connected to the open end so that the electromagnetic wave can oscillate simultaneously in the coaxial line resonator 1 and the waveguide resonator 2.

[0042] In more detail, Figure 1-Figure 3 As shown, the microwave coupling device 3 evokes electromagnetic waves in the coaxial line resonator 1, and the electromagnetic waves propagate between the first-caliber closed-loop conductive wall 11 and the second-caliber closed-loop conductive wall 12. By setting the size reasonably, the electric field at the open end of the coaxial line resonator 1 is the strongest, and the electromagnetic wave (TEM wave) can be coupled to the connection between the second-caliber closed-loop conductive wall 12 and the third-caliber closed-loop conductive wall 13 through the opening, generating an oscillating electromagnetic wave of the same mode; at this time, the electric field is the strongest at the tip of the third-caliber closed-loop conductive wall 13, and the direction of the electric field diverges around the tip of the third-caliber closed-loop conductive wall 13. At the same time, the size of the waveguide resonator 2 is reasonably set so that it works in the TM010 mode. In the TM010 mode, the electric field near the central axis is the strongest, and its direction is consistent with the top of the open end of the third-caliber closed-loop conductive wall 13. The TEM oscillation mode in the coaxial line resonator 1 can be converted into the TM010 mode, causing the waveguide resonator 2 to oscillate.

[0043] In more detail, Figure 1 and Figure 2As shown, the bottom conductive wall 14 also includes a third bottom conductive wall 143, which is arranged on the other end of the second caliber closed-loop conductive wall 12 that is arranged opposite to the open end, one end of the third bottom conductive wall 143 is connected to the second caliber closed-loop conductive wall 12, and the other end is connected to the third caliber closed-loop conductive wall 13; a second opening 2A is also provided on the area of ​​the second caliber closed-loop conductive wall 12 close to the third bottom conductive wall 143, and the second opening 2A is connected to the external airflow pipeline; a plurality of uniformly arranged third openings (not shown in the figure) are provided on the second bottom conductive wall 142, when a maintenance gas such as argon, helium or nitrogen flows in through the airflow pipeline, the electromagnetic field between the first caliber closed-loop conductive wall 11 and the second caliber closed-loop conductive wall 12 can form and maintain plasma, and when the airflow is introduced perpendicular to the central axis, the plasma will rotate around the central axis, and the size of the airflow can be controlled to form a high-speed rotating hollow plasma for sample introduction.

[0044] In detail, Figure 1-Figure 3 As shown, the third-caliber closed-loop conductive wall 13 includes a hollow structure, which is arranged coaxially with the first opening 1B to accommodate the sample introduction pipe 4; the tip of the sample introduction pipe 4 is arranged flush with the open end.

[0045] In more detail, Figure 1-Figure 3 As shown, the tip of the sample introduction pipe 4 is arranged approximately flush with the open tip of the third-caliber closed-loop conductive wall 13. There is no electromagnetic field inside the third-caliber closed-loop conductive wall 13 of the hollow structure, and the actual coupling area between the sample and the plasma is inside the waveguide resonator 2. In the waveguide resonator 2, when the electromagnetic field is not oscillating, the TEM mode has surface wave characteristics, the electromagnetic field decays rapidly, the plasma lacks electromagnetic field support, the volume becomes smaller, the temperature becomes lower, and the excitation ability of the sample is reduced. When a TM010-type mode is formed, the electromagnetic field propagates farther, the hollow plasma formed is longer, the coupling path between the plasma and the sample is longer, the temperature of the plasma is also higher, the thermal excitation of the sample is more sufficient, and the sample that can withstand more water vapor can obtain a stronger spectral signal.

[0046] In detail, as shown in FIG3 , a quartz tube 5 is provided on the side wall of the gap between the second-caliber closed-loop conductive wall surface 12 and the third-caliber closed-loop conductive wall surface 13 . The quartz tube 5 has a lower adhesion coefficient, and the analyte is not likely to remain.

[0047] Optionally, a plurality of first heat dissipation holes are provided on the first bottom conductive wall 11, and a second heat dissipation hole (such as a third opening 3B opened on the side wall) is provided on the waveguide resonator 2 to improve the heat dissipation capacity inside the resonator.

[0048] Based on the same inventive concept as the above plasma generating device, the present invention also provides a plasma generating method, which comprises the steps of:

[0049] S1, generate electromagnetic waves through a coaxial line resonator;

[0050] S2, introducing electromagnetic waves into the waveguide resonator, causing the waveguide resonator to oscillate, thereby strengthening the electromagnetic waves;

[0051] S3. Introduce a maintenance gas, and excite the maintenance gas through the enhanced electromagnetic wave to generate plasma.

[0052] In the above plasma generation method, the electromagnetic waves generated by the coaxial line resonator are oscillated and strengthened by the waveguide resonator, and the electromagnetic waves leaving the surface of the coaxial line are strengthened, thereby strengthening its coupling effect on the plasma and enhancing its ability to resist water vapor interference.

[0053] In summary, in the plasma generating device and method provided by the present invention, the coaxial line resonator and the waveguide resonator are combined to carry out the device structure design, and the open end of the coaxial line resonator is connected to an opening of the waveguide resonator, so that the electromagnetic wave can oscillate in the coaxial line resonator and the waveguide resonator at the same time, thereby strengthening the oscillation effect of the electromagnetic wave, strengthening the electromagnetic wave leaving the surface of the coaxial line, strengthening its coupling effect on the plasma, and enhancing its ability to resist water vapor interference.

[0054] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A plasma generating device, characterized in that: At least: A coaxial line resonator having an open end; The coaxial line resonator comprises a first-caliber closed-loop conductive wall, a second-caliber closed-loop conductive wall and a third-caliber closed-loop conductive wall which are sleeved on the central axis from outside to inside; the first-caliber closed-loop conductive wall, the second-caliber closed-loop conductive wall and the third-caliber closed-loop conductive wall are arranged flush at one end along the central axis, and the corresponding end is the open-circuit end of the coaxial line resonator; the coaxial line resonator also comprises a bottom conductive wall which is radially arranged along the second-caliber closed-loop conductive wall, and the bottom conductive wall is arranged along the central axis The direction of the line is far away from the open end of the coaxial line resonator, the bottom conductive wall includes a first bottom conductive wall and a second bottom conductive wall, one end of the first bottom conductive wall is connected to the first caliber closed-loop conductive wall, and the other end is connected to the second caliber closed-loop conductive wall, one end of the second bottom conductive wall is connected to the second caliber closed-loop conductive wall, and the other end is connected to the third caliber closed-loop conductive wall, a plurality of first heat dissipation holes are provided on the first bottom conductive wall, and a second heat dissipation hole is provided on the waveguide resonator; A waveguide resonator having at least two openings, which is conductively connected to the coaxial line resonator, and the open end of the coaxial line resonator is butted against one opening of the waveguide resonator, so that electromagnetic waves can oscillate simultaneously in the coaxial line resonator and the waveguide resonator; The waveguide resonator comprises a closed conductive space, the closed conductive space has at least a first opening and a second opening, the first opening is arranged opposite to the second opening, and the first opening and the second opening are arranged coaxially with the closed conductive space respectively; the first opening is butted with the open end, so that electromagnetic waves can oscillate simultaneously in the coaxial line resonator and the waveguide resonator; It also includes a microwave coupling device, which is arranged in the coaxial line resonator to generate the electromagnetic wave; wherein the inner conductor of the microwave coupling device passes through the first opening and is radially inserted into the area between the first-caliber closed-loop conductive wall surface and the second-caliber closed-loop conductive wall surface.

2. The plasma generating device according to claim 1, characterized in that: The inner diameter of the first-caliber closed-loop conductive wall surface is greater than the inner diameter of the second-caliber closed-loop conductive wall surface, and the inner diameter of the second-caliber closed-loop conductive wall surface is greater than the inner diameter of the third-caliber closed-loop conductive wall surface.

3. The plasma generating device according to claim 2, characterized in that: A first opening is provided on the first-caliber closed-loop conductive wall surface, and the first opening is used to accommodate the microwave coupling device.

4. The plasma generating device according to claim 3, characterized in that: The inner conductor of the microwave coupling device passes through the first opening and is radially inserted into the area between the first-caliber closed-loop conductive wall surface and the second-caliber closed-loop conductive wall surface, and the inner conductor of the microwave coupling device does not contact the second-caliber closed-loop conductive wall surface, so as to generate the electromagnetic wave through electric field coupling.

5. The plasma generating device according to claim 3, characterized in that: The inner conductor of the microwave coupling device passes through the first opening and is radially inserted into the area between the first-caliber closed-loop conductive wall surface and the second-caliber closed-loop conductive wall surface, and the inner conductor of the microwave coupling device is in ohmic contact with the second-caliber closed-loop conductive wall surface to generate the electromagnetic wave through magnetic field coupling.

6. The plasma generating device according to claim 4 or 5, characterized in that: The bottom conductive wall also includes a third bottom conductive wall, which is arranged on the other end of the second caliber closed-loop conductive wall opposite to the open end, one end of the third bottom conductive wall is connected to the second caliber closed-loop conductive wall, and the other end is connected to the third caliber closed-loop conductive wall; a second opening is also provided on the area of ​​the second caliber closed-loop conductive wall close to the third bottom conductive wall, and the second opening is connected to an external airflow duct; a plurality of third openings are provided on the second bottom conductive wall.

7. The plasma generating device according to claim 6, characterized in that: The third caliber closed-loop conductive wall surface comprises a hollow structure, and the hollow structure is arranged coaxially with the first opening to accommodate a sample introduction pipeline; The tip of the sample introduction channel is arranged flush with the open end.

8. The plasma generating device according to claim 7, characterized in that: A quartz pipe is provided on the side wall of the gap between the second-caliber closed-loop conductive wall surface and the third-caliber closed-loop conductive wall surface.

9. The plasma generating device according to any one of claims 1 to 8, characterized in that: In the coaxial line resonator, the electric field at the open end is the strongest; and the waveguide resonator operates in the TM010 mode.

10. A method for generating plasma, characterized in that: The method is applied to the plasma generating device according to any one of claims 1 to 9, comprising: Generate electromagnetic waves through a coaxial line resonator; Introducing the electromagnetic wave into a waveguide resonator to cause the waveguide resonator to oscillate and strengthen the electromagnetic wave; A maintenance gas is introduced, and the maintenance gas is excited by the enhanced electromagnetic wave to generate plasma.

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