CN110708853B - Waveguide Feed Microwave Coupled Plasma Generator - Google Patents

Abstract

Translated fromChinese

本发明的波导馈入式微波耦合等离子体发生装置，属于微波能应用技术领域。由波导部分和同轴谐振腔部分组成；所述的波导部分包括标准波导(2)、波导‑同轴转换锥(11)、短路活塞(12)和调节杆(13)；同轴谐振腔部分包括外导体(1)、内导体(3)、中管(4)、内管(5)、样品管(6)、样品入口(7)、内层气入口(8)、中层气入口(9)、外层气入口(10)、冷却环(14)和阻抗匹配锥(15)。本发明的装置，无射频同轴连接器与微波天线的功率输入限制，具有馈入功率大，稳定工作时间长、微波能耦合效率高等优点。

The waveguide feeding type microwave coupled plasma generating device of the invention belongs to the technical field of microwave energy application. It consists of a waveguide part and a coaxial resonant cavity part; the waveguide part includes a standard waveguide (2), a waveguide-coaxial conversion cone (11), a short-circuit piston (12) and an adjustment rod (13); the coaxial resonant cavity part Including outer conductor (1), inner conductor (3), middle tube (4), inner tube (5), sample tube (6), sample inlet (7), inner gas inlet (8), middle gas inlet (9) ), outer gas inlet (10), cooling ring (14) and impedance matching cone (15). The device of the invention has no power input limitation of the radio frequency coaxial connector and the microwave antenna, and has the advantages of large feeding power, long stable working time and high microwave energy coupling efficiency.

Description

Translated fromChinese

波导馈入式微波耦合等离子体发生装置Waveguide Feed Microwave Coupled Plasma Generator

技术领域technical field

本发明属于微波能应用技术领域，特别涉及一种波导馈入式微波耦合等离子体发生装置，具体为一种适用于千瓦级以上功率输入的微波耦合等离子体(Microwave CoupledPlasma，简称MCP)发生器。The invention belongs to the technical field of microwave energy application, in particular to a waveguide-fed microwave coupled plasma generator, in particular to a microwave coupled plasma (Microwave Coupled Plasma, MCP) generator suitable for power input above kilowatt level.

背景技术Background technique

微波等离子体炬(MPT)光谱仪激发光源所用微波谐振腔，是基于射频同轴连接器的内芯连接微波天线，经微波天线馈入微波能的一种谐振腔，相关专利如CN94205428.8。该谐振腔采用L16-KF型射频同轴连接器，长时间稳定可靠工作的平均功率仅仅为200瓦以下。再如专利CN106304602 A，采用L29-KF型射频同轴连接器连接微波天线，长时间稳定可靠工作的最高平均功率也不过在1000瓦左右。采用L16-KF或L29-KF型射频同轴连接器连接微波天线时，馈入谐振腔的微波功率受到限制，并且还存在以下两个问题：The microwave resonant cavity used for the excitation light source of the microwave plasma torch (MPT) spectrometer is a resonant cavity based on the inner core of the RF coaxial connector connected to the microwave antenna and feeding microwave energy through the microwave antenna. The resonator adopts L16-KF type RF coaxial connector, and the average power for long-term stable and reliable operation is only less than 200 watts. Another example is the patent CN106304602 A, which uses the L29-KF RF coaxial connector to connect the microwave antenna, and the maximum average power for long-term stable and reliable operation is only about 1000 watts. When using the L16-KF or L29-KF type RF coaxial connector to connect the microwave antenna, the microwave power fed into the resonant cavity is limited, and there are the following two problems:

1)馈入功率过大时，由于天线发热，引起支撑同轴连接器内芯的聚四氟乙烯支撑件变形，导致天线位置偏离正常尺寸，进而引起微波天线局部进一步过热，最终烧毁微波天线；1) When the feeding power is too large, due to the heating of the antenna, the PTFE support supporting the inner core of the coaxial connector is deformed, causing the antenna position to deviate from the normal size, which in turn causes the microwave antenna to further overheat locally and eventually burns the microwave antenna;

2)馈入功率过大时，有时在天线附近会先于谐振腔端面发生局部放电，这种局部放电更容易烧毁微波天线，造成谐振腔无法正常工作。2) When the feeding power is too large, sometimes partial discharge will occur near the antenna before the end face of the resonator. This partial discharge is more likely to burn the microwave antenna and cause the resonator to fail to work normally.

另外，天线馈入微波能时，需要在谐振腔的外导体侧面开孔安装射频同轴连接器与微波天线。外导体侧面局部开孔会破坏整个谐振腔微波电磁场的均匀分布，尤其是在电场强度最大的位置开孔时，会导致同轴谐振腔的微波能耦合效率下降。In addition, when the antenna feeds microwave energy, the radio frequency coaxial connector and the microwave antenna need to be installed on the side surface of the outer conductor of the resonant cavity. Partial openings on the side of the outer conductor will destroy the uniform distribution of the microwave electromagnetic field of the entire resonator, especially when openings are made at the position where the electric field intensity is the largest, the microwave energy coupling efficiency of the coaxial resonator will decrease.

专利号为CN103269561A的文献中，提出了一种波导直馈式微波等离子体炬装置，该装置的波导部分采用渐变型波导和窄边压缩型波导，将微波能从标准波导传输到同轴谐振腔。渐变型波导和窄边压缩型波导均属于非标部件，需要特殊加工制造。In the document with the patent number of CN103269561A, a waveguide direct-feed microwave plasma torch device is proposed. The waveguide part of the device adopts a gradient waveguide and a narrow-edge compression waveguide to transmit microwave energy from a standard waveguide to a coaxial resonant cavity. . Both graded waveguides and narrow-side compression waveguides are non-standard components that require special processing.

发明内容SUMMARY OF THE INVENTION

本发明的目的在于，克服背景技术存在的不足，提供一种波导馈入式MCP发生装置，利用标准波导和波导-同轴转换锥，将微波能直接馈入同轴谐振腔。The purpose of the present invention is to overcome the deficiencies of the background technology and provide a waveguide-fed MCP generating device, which utilizes a standard waveguide and a waveguide-coaxial conversion cone to directly feed microwave energy into a coaxial resonant cavity.

本发明的具体技术方案如下：The concrete technical scheme of the present invention is as follows:

一种波导馈入式微波耦合等离子体发生装置，由波导部分和同轴谐振腔部分组成；其特征在于，所述的波导部分包括标准波导2、波导-同轴转换锥11、短路活塞12和调节杆13；同轴谐振腔部分包括外导体1、内导体3、中管4、内管5、样品管6、样品入口7、内层气入口8、中层气入口9、外层气入口10、冷却环14和阻抗匹配锥15；A waveguide-fed microwave-coupled plasma generating device is composed of a waveguide part and a coaxial resonant cavity part; it is characterized in that, the waveguide part includes a standard waveguide 2, a waveguide-coaxial conversion cone 11, a short-circuit piston 12 and Adjustingrod 13; the coaxial resonant cavity part includes outer conductor 1, inner conductor 3, middle tube 4, inner tube 5, sample tube 6, sample inlet 7,inner gas inlet 8, middle gas inlet 9,outer gas inlet 10 ,cooling ring 14 andimpedance matching cone 15;

标准波导2的第一端口连接微波发生系统，在标准波导2第一端口与第二端口之间的长度方向垂直安装同轴谐振腔的外导体1和波导-同轴转换锥体11，并且锥体中心轴线与外导体1中心轴线重合，波导-同轴转换锥11为中空的圆台体，或中空的梯形体；标准波导2的第二端口由短路活塞12封闭，短路活塞12与调节杆13相连；The first port of the standard waveguide 2 is connected to the microwave generating system, the outer conductor 1 of the coaxial resonant cavity and the waveguide-coaxial conversion cone 11 are vertically installed in the length direction between the first port and the second port of the standard waveguide 2, and the cone The central axis of the body coincides with the central axis of the outer conductor 1, and the waveguide-coaxial conversion cone 11 is a hollow truncated body or a hollow trapezoid; the second port of the standard waveguide 2 is closed by a short-circuit piston 12, which is connected to theadjustment rod 13. connected;

外导体1、内导体3、中管4、内管5、样品管6按由外到内的顺序依次嵌套且同轴，样品管6、内管5、中管4和内导体3在所构成的谐振腔出口端面处齐平，样品管6、内管5、中管4、内导体3与外导体1构成嵌套同轴结构的微波谐振腔，该谐振腔的特性阻抗范围为50～80欧姆；Outer conductor 1, inner conductor 3, middle tube 4, inner tube 5, and sample tube 6 are nested and coaxial in order from outside to inside. Sample tube 6, inner tube 5, middle tube 4, and inner conductor 3 are in the same place. The outlet end face of the formed resonant cavity is flush, and the sample tube 6, the inner tube 5, the middle tube 4, the inner conductor 3 and the outer conductor 1 form a microwave resonant cavity with a nested coaxial structure. The characteristic impedance of the resonant cavity ranges from 50 to 50 80 ohms;

外导体1在标准波导2的第一端口和第二端口之间，与标准波导2的长度方向垂直相交，当所述的波导-同轴转换锥11为单侧锥时，外导体1的高度为所用微波波长的(2n+1)/4倍，其中n＝0、1、2或3；当所述的波导-同轴转换锥11为双侧锥时，外导体1分成上下两部分，外导体1的上半部分的底面与波导-同轴转换锥11的上锥体的下底面重合，外导体1的下半部分的顶面与波导-同轴转换锥11的下锥体的上底面重合，所述的波导-同轴转换锥11的上锥体和下锥体是两个沿标准波导2的中轴线上下对称的中空圆台，且高度之和小于标准波导2的高度，外导体1的内腔最低面与标准波导2中轴线的距离为所用微波波长的1/4倍，外导体1的内腔最低面与内腔最高面的距离为所用微波波长的(2n+1)/4倍，其中n＝1、2或3，外导体1为内部中空的圆柱体，其材质优选电阻率小于30nΩ·m的金属；The outer conductor 1 is between the first port and the second port of the standard waveguide 2, and perpendicularly intersects with the length direction of the standard waveguide 2. When the waveguide-coaxial conversion cone 11 is a single-sided cone, the height of the outer conductor 1 is (2n+1)/4 times the wavelength of the microwave used, where n=0, 1, 2 or 3; when the waveguide-coaxial conversion cone 11 is a double-sided cone, the outer conductor 1 is divided into upper and lower parts, The bottom surface of the upper half of the outer conductor 1 coincides with the lower bottom surface of the upper cone of the waveguide-coaxial conversion cone 11, and the top surface of the lower half of the outer conductor 1 is coincident with the upper surface of the lower cone of the waveguide-coaxial conversion cone 11. The bottom surfaces are coincident. The upper and lower cones of the waveguide-coaxial conversion cone 11 are two hollow circular frustums that are symmetrical up and down along the central axis of the standard waveguide 2, and the sum of the heights is less than the height of the standard waveguide 2. The outer conductor The distance between the lowest surface of the inner cavity of 1 and the central axis of the standard waveguide 2 is 1/4 times of the microwave wavelength used, and the distance between the lowest surface of the inner cavity of the outer conductor 1 and the highest surface of the inner cavity is (2n+1)/ of the microwave wavelength used. 4 times, where n=1, 2 or 3, the outer conductor 1 is a hollow cylinder, and its material is preferably a metal with a resistivity less than 30nΩ·m;

当所述的波导-同轴转换锥11为单侧锥时，内导体3经过波导-同轴转换锥11直接与标准波导2的底部紧固；当所述的波导-同轴转换锥11为双侧锥时，内导体3与外导体1的底部紧固并封闭；内导体3为内部中空的圆柱体，其材质优选电阻率小于30nΩ·m的金属；When the waveguide-coaxial conversion cone 11 is a single-sided cone, the inner conductor 3 is directly fastened to the bottom of the standard waveguide 2 through the waveguide-coaxial conversion cone 11; when the waveguide-coaxial conversion cone 11 is In the case of a double-sided taper, the inner conductor 3 and the bottom of the outer conductor 1 are fastened and closed; the inner conductor 3 is a hollow cylinder, and its material is preferably a metal with a resistivity less than 30nΩ·m;

中管4的外壁与内导体3在内导体3的下部封闭，形成底端封闭、顶部端面开放的外层气层流流动的环形间隙；中管4为内部中空的圆柱体，其材质优选电阻率小于30nΩ·m金属。The outer wall of the middle tube 4 is closed with the lower part of the inner conductor 3 and the inner conductor 3, forming an annular gap where the bottom end is closed and the top end face is open for the flow of the outer layer of laminar flow; the middle tube 4 is an inner hollow cylinder, and its material is preferably resistance The rate is less than 30nΩ·m metal.

内管5的外壁与中管4在中管4的下部封闭，形成底端封闭、顶部端面开放的中层气层流流动的环形间隙；内管5为内部中空的圆柱体，其材质优选电阻率小于30nΩ·m金属。The outer wall of the inner tube 5 and the middle tube 4 are closed at the lower part of the middle tube 4 to form an annular gap in which the bottom end is closed and the top end face is open for the flow of the laminar air flow in the middle layer; the inner tube 5 is an inner hollow cylinder, and its material is preferably resistivity. Less than 30nΩ·m metal.

样品管6的外壁与内管5在内管5的下部封闭，形成底端封闭、顶部端面开放的内层气层流流动的环形间隙；样品管6为内部中空的圆柱体，其材质既可以为金属，也可以为陶瓷、石墨、石英等非金属。The outer wall of the sample tube 6 and the inner tube 5 are closed at the lower part of the inner tube 5 to form an annular gap in which the bottom end is closed and the top end face is open for the flow of the inner layer laminar flow; the sample tube 6 is a hollow cylinder inside, and its material can be either It is a metal, and it can also be a non-metal such as ceramics, graphite, and quartz.

样品入口7位于样品管6的底端轴线位置，样品经过样品入口7进入样品管6，并在同轴谐振腔出口侧端面流出，进入等离子体，被等离子体激发、电离；The sample inlet 7 is located at the axial position of the bottom end of the sample tube 6, and the sample enters the sample tube 6 through the sample inlet 7, flows out at the end face of the outlet side of the coaxial resonant cavity, enters the plasma, and is excited and ionized by the plasma;

内层气入口8位于内管5下部靠近内管5底端的径向位置，采用径向进气方式；内层气通入由内管5内表面与样品管6外表面构成的环形间隙，并以层流状态在同轴谐振腔出口侧端面流出，电离后形成内层等离子体；The innerlayer gas inlet 8 is located at a radial position at the lower part of the inner tube 5 near the bottom end of the inner tube 5, and adopts a radial air intake method; the inner layer gas passes into the annular gap formed by the inner surface of the inner tube 5 and the outer surface of the sample tube 6, and It flows out from the end face of the outlet side of the coaxial resonant cavity in a laminar flow state, and forms an inner layer plasma after ionization;

中层气入口9位于中管4下部靠近中管4底端的径向位置，采用径向进气方式；中层气通入由中管4内表面与内管5外表面构成的环形间隙，并以层流状态在同轴谐振腔出口侧端面流出，电离后形成中层等离子体；The middle-layer gas inlet 9 is located at the radial position of the lower part of the middle-pipe 4 near the bottom end of the middle-pipe 4, and adopts a radial air intake method; The flow state flows out from the end face of the outlet side of the coaxial resonator, and forms a middle-layer plasma after ionization;

外层气入口10位于内导体3下部靠近内导体3底端的径向位置，采用径向进气方式；外层气通入由内导体3内表面与中管4外表面之间的环形间隙，并以层流状态在同轴谐振腔出口侧端面流出，电离后形成外层等离子体；The outerlayer gas inlet 10 is located at the radial position of the lower part of the inner conductor 3 close to the bottom end of the inner conductor 3, and adopts a radial air intake method; And it flows out at the end face of the outlet side of the coaxial resonant cavity in a laminar flow state, and forms an outer plasma after ionization;

内层气、中层气与外层气电离后共同构成三层等离子体炬焰，该炬焰体积适合大功率应用的需求，并使得等离子体的底部稍微脱离内导体3和样品管6之间的端面，避免该端面被大功率等离子体产生的热量烧蚀。The inner gas, the middle gas and the outer gas are ionized together to form a three-layer plasma torch. The volume of the torch is suitable for high-power applications, and the bottom of the plasma is slightly separated from the gap between the inner conductor 3 and the sample tube 6. The end face is prevented from being ablated by the heat generated by the high-power plasma.

内层气、中层气和外层气可以选用氩气、氦气或氮气工作，分别获得不同种类的等离子体，适应不同的应用场合。内层气、中层气和外层气还可以选用氙气或氪气等易电离的气体。内层气、中层气和外层气可以选用相同种类的气体工作，也可以选择不同种类的气体工作。Argon, helium or nitrogen can be selected for the inner layer gas, middle layer gas and outer layer gas to obtain different types of plasma respectively, which are suitable for different applications. The inner layer gas, the middle layer gas and the outer layer gas can also be easily ionized gases such as xenon gas or krypton gas. The inner gas, the middle gas and the outer gas can be operated with the same type of gas, or with different types of gas.

冷却环14安装于外导体1上端面下方的区间位置，冷却环14与外导体1紧密接触；冷却环14采用水冷或压缩空气制冷的方式冷却外导体1，以降低等离子体炬附近腔体的温度，保证同轴谐振腔能够长时间正常工作；Thecooling ring 14 is installed at the interval below the upper end face of the outer conductor 1, and thecooling ring 14 is in close contact with the outer conductor 1; thecooling ring 14 is cooled by water or compressed air to cool the outer conductor 1, so as to reduce the cavity near the plasma torch. temperature, to ensure that the coaxial resonator can work normally for a long time;

阻抗匹配锥15安装于外导体1的上端面，并与外导体1的上端面紧密相连接；阻抗匹配锥15的下部开口尺寸与外导体1的内径尺寸相同，阻抗匹配锥15的内表面可以为锥面，也可以为球面，还可以为旋转的抛物线曲面，其高度大于或等于所用微波波长的1/4倍。Theimpedance matching cone 15 is installed on the upper end face of the outer conductor 1 and is closely connected with the upper end face of the outer conductor 1; the size of the lower opening of theimpedance matching cone 15 is the same as the inner diameter of the outer conductor 1, and the inner surface of theimpedance matching cone 15 can be It can be a cone surface, a spherical surface, or a rotating parabolic surface, and its height is greater than or equal to 1/4 times the wavelength of the microwave used.

本发明的波导馈入式MCP发生装置，其工作过程如下：The waveguide feeding type MCP generating device of the present invention has the following working process:

当启动微波功率输出后，微波在标准波导2内部以横电模式TE10传输，并在短路活塞端12的内表面形成反射波，反射波与入射波叠加，在波导内部形成驻波。经调节杆13调节短路活塞12内表面与同轴谐振腔外导体1中心轴线之间的距离，使得同轴谐振腔外导体1的中心轴线处于标准波导2内驻波电场强度的极大位置。此时，外导体1的中心轴线与短路活塞12内表面之间的距离大约为波导波长的1/4倍或3/4倍。标准波导2中的电磁波再经波导-同轴转换锥体11作用，由TE10模平滑过渡到TEM模，TEM模电磁波经内导体3传输到同轴谐振腔中，形成另一个驻波。该驻波电场强度在同轴谐振腔的上部出口端面达到极大。在同轴谐振腔的内导体3与中管4之间、中管4与内管5之间、内管5与样品管6之间构成的三重环形间隙的出口侧端面，适当调节气体，微波电场将同时电离三重层流均匀气体，形成MCP。When the microwave power output is started, the microwave transmits in the transverse electric mode TE10 in the standard waveguide 2, and forms a reflected wave on the inner surface of the short-circuit piston end 12. The reflected wave and the incident wave are superimposed to form a standing wave inside the waveguide. The distance between the inner surface of the short-circuit piston 12 and the center axis of the outer conductor 1 of the coaxial resonator is adjusted by the adjustingrod 13 so that the center axis of the outer conductor 1 of the coaxial resonator is at the maximum position of the standing wave electric field intensity in the standard waveguide 2 . At this time, the distance between the central axis of the outer conductor 1 and the inner surface of the short-circuit piston 12 is approximately 1/4 times or 3/4 times the wavelength of the waveguide. The electromagnetic wave in the standard waveguide 2 is then acted by the waveguide-coaxial conversion cone 11 to smoothly transition from the TE10 mode to the TEM mode, and the TEM mode electromagnetic wave is transmitted to the coaxial resonator through the inner conductor 3 to form another standing wave. The electric field strength of the standing wave reaches a maximum at the upper exit end face of the coaxial resonator. On the outlet side end face of the triple annular gap formed between the inner conductor 3 and the middle tube 4, between the middle tube 4 and the inner tube 5, and between the inner tube 5 and the sample tube 6 of the coaxial resonant cavity, properly adjust the gas, microwave The electric field will simultaneously ionize the triple laminar flow of homogeneous gas to form MCP.

本发明的优点：Advantages of the present invention:

1、本发明提供的波导馈入式MCP发生装置，无射频同轴连接器与微波天线的功率输入限制、特别适合千瓦级以上微波功率馈入，长时间工作稳定可靠，可以在大气压条件下获得稳定的高温高密度等离子体。1. The waveguide feed-in MCP generator provided by the present invention has no power input limitation of radio frequency coaxial connectors and microwave antennas, and is especially suitable for microwave power feeding above kilowatts. It works stably and reliably for a long time, and can be obtained under atmospheric pressure conditions. Stable high temperature and high density plasma.

2、本发明采用波导-同轴转换锥实现微波传输模式的转换，避免使用渐变型波导和窄边压缩波导，相比于这两种特殊波导，锥体的加工更方便，成本更低。2. The present invention adopts the waveguide-coaxial conversion cone to realize the conversion of microwave transmission mode, and avoids the use of gradient waveguide and narrow-side compressed waveguide. Compared with these two special waveguides, the processing of the cone is more convenient and the cost is lower.

3、本发明可解决天线方式馈入微波能时，天线入口空洞产生的外导体内表面局部电磁场分布残缺问题，波导馈入方式保证了同轴谐振腔的内外导体之间的整体电磁场分布均匀，微波能耦合效率更高。3. The present invention can solve the problem of incomplete electromagnetic field distribution on the inner surface of the outer conductor generated by the antenna entrance cavity when the microwave energy is fed into the antenna mode. The waveguide feeding method ensures that the overall electromagnetic field distribution between the inner and outer conductors of the coaxial resonant cavity is uniform. The microwave energy coupling efficiency is higher.

附图说明：Description of drawings:

图1为本发明实施例1的单锥式MCP发生装置的结构示意图。FIG. 1 is a schematic structural diagram of a single-cone MCP generating device according to Embodiment 1 of the present invention.

图2为本发明实施例2的双锥式MCP发生装置的结构示意图。FIG. 2 is a schematic structural diagram of a double-cone MCP generating device according to Embodiment 2 of the present invention.

具体实施方式Detailed ways

下面结合附图和实施例进行具体的说明。附图只表示了本发明的优选结构，不是对本发明范围的限定。本发明可以允许其它等同的有效实施方式。Specific descriptions are given below in conjunction with the accompanying drawings and embodiments. The accompanying drawings only show the preferred structure of the present invention, and do not limit the scope of the present invention. The present invention may allow for other equally effective embodiments.

实施例1Example 1

参见图1，一种波导馈入式MCP发生装置，该发生装置主要由波导部分和同轴谐振腔部分组成。Referring to Fig. 1, a waveguide-fed MCP generating device is mainly composed of a waveguide part and a coaxial resonant cavity part.

波导部分包括标准波导2、波导-同轴转换锥11、短路活塞12和调节杆13。The waveguide part includes a standard waveguide 2 , a waveguide-coaxial conversion cone 11 , a short-circuit piston 12 and anadjustment rod 13 .

标准波导2的第一端口连接微波发生系统，在标准波导2第一端口与第二端口之间的长度方向的上部外壁垂直安装同轴谐振腔外导体1，在标准波导2长度方向的下部内壁安装波导-同轴转换锥体11，并且锥体的中心轴线与外导体1的中心轴线重合。与标准波导2第一端口端相对应的第二端口经短路活塞12封闭，短路活塞12与调节杆13相连，利用调节杆13调节短路活塞12在标准波导2中的位置。The first port of the standard waveguide 2 is connected to the microwave generating system, the coaxial resonator outer conductor 1 is vertically installed on the upper outer wall in the length direction between the first port and the second port of the standard waveguide 2, and the lower inner wall in the length direction of the standard waveguide 2 is installed vertically. The waveguide-coaxial conversion cone 11 is installed, and the central axis of the cone coincides with the central axis of the outer conductor 1 . The second port corresponding to the first port end of the standard waveguide 2 is closed by a short-circuit piston 12 , the short-circuit piston 12 is connected with the adjustingrod 13 , and the position of the short-circuit piston 12 in the standard waveguide 2 is adjusted by the adjustingrod 13 .

本例中，标准波导2采用BJ26型矩形波导，其内壁横截面尺寸为宽86.4mm，高43.2mm。当然，也可以采用其它尺寸的波导，如BJ22型或BZ26型矩形波导。波导内壁和短路活塞内壁镀铜或镀银。In this example, the standard waveguide 2 adopts a BJ26 type rectangular waveguide, and the cross-sectional dimension of its inner wall is 86.4mm wide and 43.2mm high. Of course, other sizes of waveguides can also be used, such as BJ22 type or BZ26 type rectangular waveguides. The inner wall of the waveguide and the inner wall of the shorting piston are copper or silver plated.

波导-同轴转换锥体11为圆台型单侧锥体，锥体角度为40度。锥体上底面与内导体3封闭，锥体下底面与标准波导2的下部外壁封闭。The waveguide-coaxial conversion cone 11 is a truncated cone-shaped single-sided cone, and the cone angle is 40 degrees. The upper bottom surface of the cone is closed with the inner conductor 3 , and the lower bottom surface of the cone is closed with the lower outer wall of the standard waveguide 2 .

微波在标准波导2内部以横电模式TE10传输，并在短路活塞端12的内表面形成反射波，反射波与入射波叠加，在波导内部形成驻波。为了最大限度地将微波能馈入到同轴谐振腔，降低微波反射功率，有利于激发等离子体，必需通过调节杆13调节短路活塞12内表面与同轴谐振腔外导体1的中心轴线之间的距离，使得同轴谐振腔外导体1的中心轴线处于标准波导2内驻波电场强度的极大位置。本例中，外导体1的中心轴线与短路活塞12内表面之间的距离为波导波长的1/4倍或3/4倍。The microwave transmits in the transverse electric mode TE10 inside the standard waveguide 2, and forms a reflected wave on the inner surface of the short-circuit piston end 12. The reflected wave and the incident wave are superimposed to form a standing wave inside the waveguide. In order to feed the microwave energy into the coaxial resonator to the maximum extent, reduce the microwave reflected power, and facilitate the excitation of the plasma, it is necessary to adjust the distance between the inner surface of the short-circuit piston 12 and the central axis of the outer conductor 1 of the coaxial resonator through the adjustingrod 13 The distance is such that the central axis of the outer conductor 1 of the coaxial resonator is at the maximum position of the electric field strength of the standing wave in the standard waveguide 2 . In this example, the distance between the central axis of the outer conductor 1 and the inner surface of the short-circuit piston 12 is 1/4 times or 3/4 times the wavelength of the waveguide.

标准波导2中的电磁波经波导-同轴转换锥体11作用，由TE10模平滑过渡到TEM模，TEM模电磁波经内导体3传输到同轴谐振腔中，形成另一个驻波。该驻波电场强度在同轴谐振腔的上部出口端面达到极大，若在出口端面处气体调节合适，很容易形成MCP。The electromagnetic wave in the standard waveguide 2 is acted on by the waveguide-coaxial conversion cone 11, and smoothly transitions from the TE10 mode to the TEM mode, and the TEM mode electromagnetic wave is transmitted to the coaxial resonant cavity through the inner conductor 3 to form another standing wave. The electric field strength of the standing wave reaches a maximum at the upper outlet end face of the coaxial resonator. If the gas is properly adjusted at the outlet end face, it is easy to form MCP.

同轴谐振腔部分包括外导体1、内导体3、中管4、内管5、样品管6、样品入口7、内层气入口8、中层气入口9、外层气入口10、冷却环14和阻抗匹配锥15。其中，外导体1内部设计有内导体3，内导体3内部设计有中管4，中管4内部设计有内管5，内管5内部设计有样品管6。样品管6的中心轴线与同轴谐振腔的中心轴线重合，样品管6与内管5同轴，内管5与中管4同轴，中管4与内导体3同轴，内导体3与外导体1同轴，并且样品管6、内管5、中管4和内导体3在谐振腔出口端面齐平。样品管6、内管5、中管4、内导体3与外导体1构成嵌套同轴结构的微波谐振腔，该同轴谐振腔的特性阻抗范围为50～80欧姆。The coaxial resonant cavity part includes outer conductor 1, inner conductor 3, middle tube 4, inner tube 5, sample tube 6, sample inlet 7,inner gas inlet 8, middle gas inlet 9,outer gas inlet 10, coolingring 14 andimpedance matching cone 15. The inner conductor 3 is designed inside the outer conductor 1 , the middle tube 4 is designed inside the inner conductor 3 , the inner tube 5 is designed inside the middle tube 4 , and the sample tube 6 is designed inside the inner tube 5 . The central axis of the sample tube 6 coincides with the central axis of the coaxial resonant cavity, the sample tube 6 is coaxial with the inner tube 5, the inner tube 5 is coaxial with the middle tube 4, the middle tube 4 is coaxial with the inner conductor 3, and the inner conductor 3 is coaxial with the inner conductor 3. The outer conductor 1 is coaxial, and the sample tube 6, the inner tube 5, the middle tube 4 and the inner conductor 3 are flush with the end face of the outlet of the resonant cavity. The sample tube 6 , the inner tube 5 , the middle tube 4 , the inner conductor 3 and the outer conductor 1 form a microwave resonant cavity with a nested coaxial structure, and the characteristic impedance of the coaxial resonant cavity ranges from 50 to 80 ohms.

外导体1在标准波导2的第一端口和第二端口之间，垂直于标准波导2的长度方向安装，外导体1的中心轴线与波导-同轴转换锥11的中心轴线重合。外导体1为内部中空的圆柱体，内径为35～60mm。外导体上部端面距离标准波导2外壁大约90～100mm。外导体1的材质为高导电率、低损耗的金属，如无氧铜、紫铜或高纯铝，或者采用铜合金、铝合金加工，为提高腔体Q值，内表面镀银。外导体内表面要进行防锈、防腐处理。The outer conductor 1 is installed between the first port and the second port of the standard waveguide 2 , perpendicular to the length direction of the standard waveguide 2 , and the central axis of the outer conductor 1 coincides with the central axis of the waveguide-coaxial conversion cone 11 . The outer conductor 1 is a hollow cylinder with an inner diameter of 35-60 mm. The upper end face of the outer conductor is about 90-100 mm away from the outer wall of the standard waveguide 2 . The material of the outer conductor 1 is a metal with high conductivity and low loss, such as oxygen-free copper, red copper or high-purity aluminum, or is processed by copper alloy or aluminum alloy. In order to improve the Q value of the cavity, the inner surface is plated with silver. The inner surface of the outer conductor should be treated with anti-rust and anti-corrosion treatment.

内导体3经过波导-同轴转换锥11直接紧固于标准波导2的底部，并从标准波导2的下部内壁伸出。内导体3为内部中空的圆柱体，其内部放置中管4、内管5和样品管6。本例中，内导体外径10～18mm，内径为9～16mm。内导体3材质可以为高导电率、低损耗的金属材料，如无氧铜、紫铜等纯铜材料或者高纯铝、铜合金、铝合金加工而成，外表面镀银，并采取防锈防腐处理。The inner conductor 3 is directly fastened to the bottom of the standard waveguide 2 through the waveguide-coaxial conversion cone 11 and protrudes from the lower inner wall of the standard waveguide 2 . The inner conductor 3 is a hollow cylinder inside, and the middle tube 4 , the inner tube 5 and the sample tube 6 are placed inside. In this example, the outer diameter of the inner conductor is 10 to 18 mm, and the inner diameter is 9 to 16 mm. The inner conductor 3 can be made of metal materials with high conductivity and low loss, such as pure copper materials such as oxygen-free copper and red copper, or high-purity aluminum, copper alloy, and aluminum alloy. deal with.

中管4与内导体3在内导体3的下部封闭，形成一端封闭、另一端在同轴谐振腔出口侧端面开放的外层气层流流动的环形间隙。中管4为内部中空的圆柱体，其材质为高导电率、低损耗的金属。The middle tube 4 and the inner conductor 3 are closed at the lower part of the inner conductor 3 to form an annular gap where one end is closed and the other end is open at the end face of the coaxial resonant cavity outlet side for the outer layer gas laminar flow to flow. The middle tube 4 is a hollow cylinder inside, and its material is a metal with high conductivity and low loss.

内管5与中管4在中管4的下部封闭，形成一端封闭、另一端在同轴谐振腔出口侧端面开放的中层气层流流动的环形间隙。内管5为内部中空的圆柱体，其材质为高导电率、低损耗的金属。The inner tube 5 and the middle tube 4 are closed at the lower part of the middle tube 4 to form an annular gap where one end is closed and the other end is open at the end face of the coaxial resonant cavity outlet side. The inner tube 5 is a hollow cylinder, and its material is a metal with high conductivity and low loss.

样品管6与内管5在内管5的下部封闭，形成一端封闭、另一端在同轴谐振腔出口侧端面开放的内层气层流流动的环形间隙。样品管6同样为内部中空的圆柱体，其材质既可以为金属，也可以为陶瓷、石墨、石英等非金属。The sample tube 6 and the inner tube 5 are closed at the lower part of the inner tube 5 to form an annular gap where one end is closed and the other end is open at the end face of the coaxial resonant cavity outlet side for the inner layer gas laminar flow to flow. The sample tube 6 is also a hollow cylinder, and its material can be either metal or non-metal such as ceramics, graphite, and quartz.

样品入口7位于样品管6的末端轴线位置，气溶胶样品经过样品入口7进入样品管6，并在同轴谐振腔出口侧端面流出，进入等离子体的中央通道，被激发、电离。The sample inlet 7 is located at the end axis of the sample tube 6. The aerosol sample enters the sample tube 6 through the sample inlet 7 and flows out at the end face of the coaxial resonator outlet side, enters the central channel of the plasma, and is excited and ionized.

内层气入口8位于内管5下部靠近内管5末端的径向位置，采用径向进气方式。内层气通入内管5内表面与样品管6外表面构成的环形间隙，并以层流状态在同轴谐振腔出口侧端面流出，电离后形成内层等离子体。The innerlayer air inlet 8 is located at a radial position at the lower part of the inner tube 5 near the end of the inner tube 5, and adopts a radial air intake method. The inner layer gas flows into the annular gap formed by the inner surface of the inner tube 5 and the outer surface of the sample tube 6, and flows out from the end face of the outlet side of the coaxial resonant cavity in a laminar flow state, and forms an inner layer plasma after ionization.

中层气入口9位于中管4下部靠近中管4末端的径向位置，采用径向进气方式。中层气通入中管4内表面与内管5外表面构成的环形间隙，并以层流状态在谐振腔出口侧端面流出，电离后形成中层等离子体。The air inlet 9 of the middle layer is located at a radial position at the lower part of the middle pipe 4 close to the end of the middle pipe 4, and adopts a radial air intake method. The middle layer gas passes into the annular gap formed by the inner surface of the middle tube 4 and the outer surface of the inner tube 5, and flows out from the end face of the outlet side of the resonance cavity in a laminar flow state, and forms a middle layer plasma after ionization.

外层气入口10位于内导体3下部靠近内导体3末端的径向位置，采用径向进气方式。外层气通入内导体3内表面与中管4外表面之间的环形间隙，并以层流状态在谐振腔出口侧端面流出，电离后形成外层等离子体。The outerlayer air inlet 10 is located at a radial position at the lower part of the inner conductor 3 close to the end of the inner conductor 3, and adopts a radial air intake method. The outer layer gas passes into the annular gap between the inner surface of the inner conductor 3 and the outer surface of the middle tube 4, and flows out from the end face of the outlet side of the resonator cavity in a laminar flow state, and forms an outer layer plasma after ionization.

内层气、中层气与外层气电离后共同构成三层等离子体炬焰，该炬焰体积适合大功率应用的需求，并使得等离子体的底部稍微脱离内导体3和样品管6之间的端面，避免该端面被大功率等离子体产生的热量烧蚀。The inner gas, the middle gas and the outer gas are ionized together to form a three-layer plasma torch. The volume of the torch is suitable for high-power applications, and the bottom of the plasma is slightly separated from the gap between the inner conductor 3 and the sample tube 6. The end face is prevented from being ablated by the heat generated by the high-power plasma.

内层气、中层气和外层气可以选用氩气、氦气或氮气工作，分别获得不同种类的等离子体，适应不同的应用场合。内层气、中层气和外层气还可以选用氙气或氪气等易电离的气体。Argon, helium or nitrogen can be selected for the inner layer gas, middle layer gas and outer layer gas to obtain different types of plasma respectively, which are suitable for different applications. The inner layer gas, the middle layer gas and the outer layer gas can also be easily ionized gases such as xenon gas or krypton gas.

内层气、中层气和外层气可以选用相同种类的气体工作，也可以选择不同种类的气体工作。The inner gas, the middle gas and the outer gas can be operated with the same type of gas, or with different types of gas.

冷却环14安装于外导体1上端面偏下的区间位置，冷却环14与外导体1紧密接触。冷却环14采用水冷或压缩空气制冷的方式冷却外导体1，以降低等离子体炬附近腔体的温度，保证同轴谐振腔能够长时间正常工作。冷却管经过气泵或水泵连接制冷散热器，气泵或水泵提供冷却动力或循环动力，使得气或水在制冷散热装置与水冷装置之间循环，以实现降温的功能。Thecooling ring 14 is installed in the lower section of the upper end surface of the outer conductor 1 , and thecooling ring 14 is in close contact with the outer conductor 1 . Thecooling ring 14 uses water cooling or compressed air cooling to cool the outer conductor 1 to reduce the temperature of the cavity near the plasma torch and ensure that the coaxial resonant cavity can work normally for a long time. The cooling pipe is connected to the cooling radiator through an air pump or water pump, and the air pump or water pump provides cooling power or circulation power, so that air or water circulates between the cooling and cooling device and the water cooling device to achieve the function of cooling.

阻抗匹配锥15安装于外导体1的上端面，并与之紧密相连接。阻抗匹配锥15的下部开口尺寸与外导体1的内径尺寸相同，其内表面可以为锥面，也可以为球面，还可以为旋转的抛物线曲面，其高度大于或等于所用微波波长的1/4倍。阻抗匹配锥15用来实现同轴谐振腔的特性阻抗与自由空间阻抗近似匹配，降低反射功率，稳定炬焰，并防止微波泄漏，保护微波发生系统正常稳定的工作。Theimpedance matching cone 15 is installed on the upper end face of the outer conductor 1 and is closely connected with it. The size of the lower opening of theimpedance matching cone 15 is the same as the size of the inner diameter of the outer conductor 1. The inner surface of theimpedance matching cone 15 can be a cone surface, a spherical surface, or a rotating parabolic surface, and its height is greater than or equal to 1/4 of the microwave wavelength used. times. Theimpedance matching cone 15 is used to achieve approximate matching between the characteristic impedance of the coaxial resonator cavity and the free space impedance, reduce the reflected power, stabilize the torch flame, prevent microwave leakage, and protect the normal and stable operation of the microwave generating system.

本发明实施例1的简要工作过程如下：The brief working process of Embodiment 1 of the present invention is as follows:

1开启水冷或压缩空气冷却系统；1 Turn on the water cooling or compressed air cooling system;

2启动微波控制系统电源，进行预热；2 Start the power supply of the microwave control system for preheating;

3开启钢瓶阀门，调节外层气、中层气、内层气的气体流量，例如，外层气1.5L/min，中层气1.0L/min，内层气1.0L/min，进行管线吹扫，排出腔内积存的空气；3 Open the valve of the cylinder, adjust the gas flow of the outer gas, the middle gas and the inner gas, for example, the outer gas is 1.5L/min, the middle gas is 1.0L/min, and the inner gas is 1.0L/min, and the pipeline is purged. Expel the air accumulated in the cavity;

4开启微波输出，利用磁控管(未标出)产生频率2.45GHz，千瓦级以上功率的微波。微波在标准波导2内部以横电模式TE10传输，并在短路活塞端12的内表面形成反射波，反射波与入射波叠加，在波导内部形成驻波。经调节杆13调节短路活塞12内表面与同轴谐振腔外导体1中心轴线之间的距离，使得同轴谐振腔外导体1的轴线处于标准波导2内驻波电场强度的极大位置。此时，外导体1的中心轴线与短路活塞12内表面之间的距离大约为波导波长的1/4倍或3/4倍。标准波导2中的电磁波再经波导-同轴转换锥体11作用，由TE10模平滑过渡到TEM模，TEM模电磁波经内导体3传输到同轴谐振腔中，形成另一个驻波。该驻波电场强度在同轴谐振腔的上部出口端面达到极大。当在同轴谐振腔的内导体3与中管4之间、中管4与内管5之间、内管5与样品管6之间构成的三重环形间隙的出口侧端面，若气体调节合适，此时点火器同时动作，释放初始电子，引起端面附近的气体产生电子雪崩反应，微波电场同时电离三重层流均匀气体，在出口端面处引燃MCP炬焰。4. Turn on the microwave output, and use a magnetron (not shown) to generate microwaves with a frequency of 2.45GHz and a power above the kilowatt level. The microwave transmits in the transverse electric mode TE10 inside the standard waveguide 2, and forms a reflected wave on the inner surface of the short-circuit piston end 12. The reflected wave and the incident wave are superimposed to form a standing wave inside the waveguide. The distance between the inner surface of the short-circuit piston 12 and the central axis of the outer conductor 1 of the coaxial resonator is adjusted by the adjustingrod 13 so that the axis of the outer conductor 1 of the coaxial resonator is at the maximum position of the electric field strength of the standing wave in the standard waveguide 2 . At this time, the distance between the central axis of the outer conductor 1 and the inner surface of the short-circuit piston 12 is approximately 1/4 times or 3/4 times the wavelength of the waveguide. The electromagnetic wave in the standard waveguide 2 is then acted by the waveguide-coaxial conversion cone 11 to smoothly transition from the TE10 mode to the TEM mode, and the TEM mode electromagnetic wave is transmitted to the coaxial resonator through the inner conductor 3 to form another standing wave. The electric field strength of the standing wave reaches a maximum at the upper exit end face of the coaxial resonator. When the outlet side end face of the triple annular gap formed between the inner conductor 3 and the middle tube 4 of the coaxial resonant cavity, between the middle tube 4 and the inner tube 5, and between the inner tube 5 and the sample tube 6, if the gas is adjusted properly , at this time, the igniter acts at the same time to release the initial electrons, causing the gas near the end face to produce an electron avalanche reaction, and the microwave electric field ionizes the triple laminar flow uniform gas at the same time, igniting the MCP torch flame at the outlet end face.

实施例2Example 2

参见图2，该发生装置主要由波导部分和同轴谐振腔部分组成。Referring to Fig. 2, the generating device is mainly composed of a waveguide part and a coaxial resonant cavity part.

波导部分包括标准波导2、波导-同轴转换锥11、短路活塞12和调节杆13。其中，标准波导2、短路活塞12和调节杆13与实施例1完全相同，仅仅波导-同轴转换锥11与实施例1不同。The waveguide part includes a standard waveguide 2 , a waveguide-coaxial conversion cone 11 , a short-circuit piston 12 and anadjustment rod 13 . The standard waveguide 2 , the short-circuit piston 12 and theadjustment rod 13 are exactly the same as those of the first embodiment, and only the waveguide-coaxial conversion cone 11 is different from that of the first embodiment.

波导-同轴转换锥11为两个尺寸相同的部件，分别安装于标准波导2内壁的上下两侧，锥体中心轴线与外导体1的中心轴线重合。该锥体既可以为圆台型锥体，优选的，锥体角度为40度；还可以为对称的梯形体，优选的，梯形角度为40度。The waveguide-coaxial conversion cone 11 is two parts with the same size, which are respectively installed on the upper and lower sides of the inner wall of the standard waveguide 2 , and the central axis of the cone coincides with the central axis of the outer conductor 1 . The cone can be either a truncated cone, preferably, the angle of the cone is 40 degrees; it can also be a symmetrical trapezoid, preferably, the angle of the trapezoid is 40 degrees.

同轴谐振腔部分包括外导体1、内导体3、中管4、内管5、样品管6、样品入口7、内层气入口8、中层气入口9、外层气入口10、冷却环14和阻抗匹配锥15。除外导体1分为上下两个部分之外，同轴谐振腔的其余部分与本发明的实施例1相同，在此不再赘述。The coaxial resonant cavity part includes outer conductor 1, inner conductor 3, middle tube 4, inner tube 5, sample tube 6, sample inlet 7,inner gas inlet 8, middle gas inlet 9,outer gas inlet 10, coolingring 14 andimpedance matching cone 15. Except that the outer conductor 1 is divided into upper and lower parts, the rest of the coaxial resonant cavity is the same as that of Embodiment 1 of the present invention, which is not repeated here.

外导体1在标准波导2的第一端口和第二端口之间，垂直于标准波导2的长度方向安装。外导体1分成上下两个部分，外导体上部与标准波导2第一端口和第二端口之间的长度方向的上壁外侧紧固，外导体下部与标准波导2第一端口和第二端口之间的长度方向的下壁外侧紧固。外导体下部与外导体上部同轴，并与内导体3紧固封闭。The outer conductor 1 is installed between the first port and the second port of the standard waveguide 2 and is perpendicular to the length direction of the standard waveguide 2 . The outer conductor 1 is divided into upper and lower parts, the upper part of the outer conductor is fastened to the outside of the upper wall in the length direction between the first port and the second port of the standard waveguide 2, and the lower part of the outer conductor is connected to the first port and the second port of the standard waveguide 2. Fasten on the outside of the lower wall in the length direction between the two. The lower part of the outer conductor is coaxial with the upper part of the outer conductor, and is tightly closed with the inner conductor 3 .

优选的，外导体上端面与外导体底面的总体深度为所用微波波长的(2n+1)/4倍(n＝1，2，3)，并且双侧锥体在标准波导2高度方向上的对称中心线位于距离外导体底面为所用微波波长的1/4倍的位置。例如，当n＝1时，外导体上部端面距离腔体底面大约90～100mm。并且两侧锥体在标准波导2高度方向的对称中心线位于距离外导体底面约为30～31mm的位置。Preferably, the overall depth of the upper end surface of the outer conductor and the bottom surface of the outer conductor is (2n+1)/4 times the wavelength of the microwave used (n=1, 2, 3), and the depth of the double-sided cone in the height direction of the standard waveguide 2 is The center line of symmetry is located at 1/4 times the wavelength of the microwave used from the bottom surface of the outer conductor. For example, when n=1, the distance between the upper end surface of the outer conductor and the bottom surface of the cavity is about 90-100 mm. In addition, the symmetrical centerlines of the cones on both sides in the height direction of the standard waveguide 2 are located at a distance of about 30-31 mm from the bottom surface of the outer conductor.

尽管上述内容涉及了本发明的实施方式，但是，在不背离本发明基本范围及权利要求的所要保护范围情况下，本发明可以具有其它的实施方式。Although the above description relates to the embodiments of the present invention, the present invention may have other embodiments without departing from the basic scope of the present invention and the intended protection scope of the claims.

Claims (3)

Translated fromChinese

1.一种波导馈入式微波耦合等离子体发生装置，由波导部分和同轴谐振腔部分组成；其特征在于，所述的波导部分包括标准波导（2）、波导-同轴转换锥（11）、短路活塞（12）和调节杆（13）；同轴谐振腔部分包括外导体（1）、内导体（3）、中管（4）、内管（5）、样品管（6）、样品入口（7）、内层气入口（8）、中层气入口（9）、外层气入口（10）、冷却环（14）和阻抗匹配锥（15）；1. A waveguide-fed microwave-coupled plasma generating device, comprising a waveguide portion and a coaxial resonant cavity portion; characterized in that, the waveguide portion comprises a standard waveguide (2), a waveguide-coaxial conversion cone (11 ), a short-circuit piston (12) and an adjusting rod (13); the coaxial resonant cavity part includes an outer conductor (1), an inner conductor (3), a middle tube (4), an inner tube (5), a sample tube (6), a sample inlet (7), an inner layer gas inlet (8), a middle layer gas inlet (9), an outer layer gas inlet (10), a cooling ring (14) and an impedance matching cone (15);标准波导（2）的第一端口连接微波发生系统，在标准波导（2）第一端口与第二端口之间的长度方向垂直安装同轴谐振腔的外导体（1）和波导-同轴转换锥（11），并且锥体中心轴线与外导体（1）中心轴线重合，波导-同轴转换锥（11）为中空的圆台体，或中空的梯形体；标准波导（2）的第二端口由短路活塞（12）封闭，短路活塞（12）与调节杆（13）相连；The first port of the standard waveguide (2) is connected to the microwave generating system, and the outer conductor (1) of the coaxial resonant cavity and the waveguide-coaxial conversion are vertically installed in the length direction between the first port and the second port of the standard waveguide (2) Cone (11), and the central axis of the cone coincides with the central axis of the outer conductor (1), the waveguide-coaxial conversion cone (11) is a hollow truncated body, or a hollow trapezoidal body; the second port of the standard waveguide (2) It is closed by the short-circuit piston (12), and the short-circuit piston (12) is connected with the adjustment rod (13);外导体（1）、内导体（3）、中管（4）、内管（5）、样品管（6）按由外到内的顺序依次嵌套且同轴，样品管（6）、内管（5）、中管（4）和内导体（3）在所构成的谐振腔出口端面处齐平，样品管（6）、内管（5）、中管（4）、内导体（3）与外导体（1）构成嵌套同轴结构的微波谐振腔，该谐振腔的特性阻抗范围为50～80欧姆；The outer conductor (1), the inner conductor (3), the middle tube (4), the inner tube (5), and the sample tube (6) are nested and coaxial in order from the outside to the inside. The tube (5), the middle tube (4) and the inner conductor (3) are flush at the outlet end face of the formed resonant cavity, the sample tube (6), the inner tube (5), the middle tube (4), the inner conductor (3) ) and the outer conductor (1) to form a microwave resonant cavity with a nested coaxial structure, and the characteristic impedance of the resonant cavity ranges from 50 to 80 ohms;外导体（1）在标准波导（2）的第一端口和第二端口之间，与标准波导（2）的长度方向垂直相交，所述的波导-同轴转换锥（11）为双侧锥，外导体（1）分成上下两部分，外导体（1）的上半部分的底面与波导-同轴转换锥（11）的上锥体的下底面重合，外导体（1）的下半部分的顶面与波导-同轴转换锥（11）的下锥体的上底面重合，所述的波导-同轴转换锥（11）的上锥体和下锥体是两个沿标准波导（2）的中轴线上下对称的中空圆台，且高度之和小于标准波导（2）的高度，外导体（1）的内腔最低面与标准波导（2）中轴线的距离为所用微波波长的1/4倍，外导体（1）的内腔最低面与内腔最高面的距离为所用微波波长的(2n+1)/4倍，其中n =1、2或3，外导体（1）为内部中空的金属圆柱体；The outer conductor (1) is between the first port and the second port of the standard waveguide (2), and perpendicularly intersects with the length direction of the standard waveguide (2), and the waveguide-coaxial conversion cone (11) is a double-sided cone , the outer conductor (1) is divided into upper and lower parts, the bottom surface of the upper half of the outer conductor (1) coincides with the lower bottom surface of the upper cone of the waveguide-coaxial conversion cone (11), and the lower half of the outer conductor (1) The top surface coincides with the upper bottom surface of the lower cone of the waveguide-coaxial conversion cone (11), and the upper cone and the lower cone of the waveguide-coaxial conversion cone (11) are two along the standard waveguide (2). ) is a hollow truncated truncated truncated up and down symmetrical central axis, and the sum of the heights is less than the height of the standard waveguide (2), and the distance between the lowest surface of the inner cavity of the outer conductor (1) and the central axis of the standard waveguide (2) is 1/1 of the microwave wavelength used. 4 times, the distance between the lowest surface of the inner cavity of the outer conductor (1) and the highest surface of the inner cavity is (2n+1)/4 times the wavelength of the microwave used, where n = 1, 2 or 3, and the outer conductor (1) is the inner a hollow metal cylinder;内导体（3）与外导体（1）的底部紧固并封闭；内导体（3）为内部中空的金属圆柱体；The bottom of the inner conductor (3) and the outer conductor (1) are fastened and closed; the inner conductor (3) is a hollow metal cylinder inside;中管（4）的外壁与内导体（3）在内导体（3）的下部封闭，形成底端封闭、顶部端面开放的外层气层流流动的环形间隙；中管（4）为内部中空的金属圆柱体；The outer wall of the middle tube (4) is closed with the lower part of the inner conductor (3) and the lower part of the inner conductor (3) is formed to form an annular gap for the flow of the outer laminar flow with the bottom end closed and the top end face open; the middle tube (4) is hollow inside the metal cylinder;内管（5）的外壁与中管（4）在中管（4）的下部封闭，形成底端封闭、顶部端面开放的中层气层流流动的环形间隙；内管（5）为内部中空的金属圆柱体；The outer wall of the inner tube (5) and the middle tube (4) are closed at the lower part of the middle tube (4) to form an annular gap for the flow of the middle layer air laminar flow with a closed bottom end and an open top end face; the inner tube (5) is hollow inside. metal cylinder;样品管（6）的外壁与内管（5）在内管（5）的下部封闭，形成底端封闭、顶部端面开放的内层气层流流动的环形间隙；样品管（6）为内部中空的圆柱体；The outer wall of the sample tube (6) and the inner tube (5) are closed at the lower part of the inner tube (5) to form an annular gap in which the bottom end is closed and the top end face is open for the flow of the inner layer laminar flow; the sample tube (6) is hollow inside the cylinder;样品入口（7）位于样品管（6）的底端轴线位置，样品经过样品入口（7）进入样品管（6），并在同轴谐振腔出口侧端面流出，进入等离子体，被等离子体激发、电离；The sample inlet (7) is located at the axial position of the bottom end of the sample tube (6). The sample enters the sample tube (6) through the sample inlet (7), flows out at the end face of the outlet side of the coaxial resonant cavity, enters the plasma, and is excited by the plasma ,ionization;内层气入口（8）位于内管（5）下部靠近内管（5）底端的径向位置，采用径向进气方式；内层气通入由内管（5）内表面与样品管（6）外表面构成的环形间隙，并以层流状态在同轴谐振腔出口侧端面流出，电离后形成内层等离子体；The inner layer gas inlet (8) is located at a radial position at the lower part of the inner tube (5) close to the bottom end of the inner tube (5), and adopts a radial air intake method; 6) The annular gap formed by the outer surface flows out in a laminar flow state at the end face of the outlet side of the coaxial resonator cavity, and forms an inner layer plasma after ionization;中层气入口（9）位于中管（4）下部靠近中管（4）底端的径向位置，采用径向进气方式；中层气通入由中管（4）内表面与内管（5）外表面构成的环形间隙，并以层流状态在同轴谐振腔出口侧端面流出，电离后形成中层等离子体；The middle-layer gas inlet (9) is located at a radial position at the lower part of the middle-pipe (4) close to the bottom end of the middle-pipe (4), and adopts a radial air intake method; The annular gap formed by the outer surface flows out in a laminar flow state at the end face of the outlet side of the coaxial resonant cavity, and forms a middle-layer plasma after ionization;外层气入口（10）位于内导体（3）下部靠近内导体（3）底端的径向位置，采用径向进气方式；外层气通入由内导体（3）内表面与中管（4）外表面之间的环形间隙，并以层流状态在同轴谐振腔出口侧端面流出，电离后形成外层等离子体；The outer layer gas inlet (10) is located at a radial position at the lower part of the inner conductor (3) close to the bottom end of the inner conductor (3), and adopts a radial air intake method; 4) The annular gap between the outer surfaces flows out in a laminar flow state at the end face of the outlet side of the coaxial resonator, and forms an outer plasma after ionization;冷却环（14）安装于外导体（1）上端面下方的区间位置，冷却环（14）与外导体（1）紧密接触；冷却环（14）采用水冷或压缩空气制冷的方式冷却外导体（1），以降低等离子体炬附近腔体的温度，保证同轴谐振腔能够长时间正常工作；The cooling ring (14) is installed at the interval below the upper end face of the outer conductor (1), and the cooling ring (14) is in close contact with the outer conductor (1); the cooling ring (14) is cooled by water or compressed air to cool the outer conductor ( 1), to reduce the temperature of the cavity near the plasma torch and ensure that the coaxial resonator can work normally for a long time;阻抗匹配锥（15）安装于外导体（1）的上端面，并与外导体（1）的上端面紧密相连接；阻抗匹配锥（15）的下部开口尺寸与外导体（1）的内径尺寸相同，阻抗匹配锥（15）的内表面为旋转的抛物线曲面，其高度大于或等于所用微波波长的1/4倍。The impedance matching cone (15) is installed on the upper end face of the outer conductor (1) and is closely connected with the upper end face of the outer conductor (1); the size of the lower opening of the impedance matching cone (15) is the same as the size of the inner diameter of the outer conductor (1). Similarly, the inner surface of the impedance matching cone (15) is a rotating parabolic surface, and its height is greater than or equal to 1/4 times of the microwave wavelength used.2.根据权利要求1所述的一种波导馈入式微波耦合等离子体发生装置，其特征在于，所述的外导体（1）、内导体（3）、中管（4）以及内管（5）是由电阻率小于30 nΩ· m的金属制成的。2 . The waveguide-fed microwave coupled plasma generating device according to claim 1 , wherein the outer conductor ( 1 ), the inner conductor ( 3 ), the middle tube ( 4 ) and the inner tube ( 5) is made of metal with resistivity less than 30 nΩ m.3.根据权利要求1所述的一种波导馈入式微波耦合等离子体发生装置，其特征在于，所述的样品管（6）是由金属、陶瓷、石墨或石英制成的。3 . The waveguide-fed microwave coupled plasma generating device according to claim 1 , wherein the sample tube ( 6 ) is made of metal, ceramic, graphite or quartz. 4 .

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