JP2007059318A - Plasma generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma generator capable of efficiently irradiating microwaves into liquid. <P>SOLUTION: In this plasma generator, a transducer 21 of an ultrasonic generator produces cavitation frequently by irradiating ultrasonic waves into liquid W in a container 12. A waveguide 29 of a microwave generator makes discharge plasma generate by irradiating microwaves into a cavitation generating region R in the liquid W. The waveguide 29 has a tube body 31 of which the top portion is protruded into the container 12 and a microwave transmission medium 32 disposed inside the top portion of the tube body 31. A taper face 36 inclined in a longitudinal direction of the tube body 31 is formed on the top portion of the microwave transmission medium 32. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plasma generator for generating plasma by irradiating a liquid with ultrasonic waves and microwaves.

  When a liquid is irradiated with powerful ultrasonic waves in a predetermined frequency range, bubbles called cavitation are generated, and a reaction field of several thousand degrees and several thousand atmospheres called hot spots is formed locally through compression and collapse processes. It is known. In recent years, this reaction field has attracted attention as a kind of limit reaction field, and liquid processing (for example, induction / promotion of chemical reaction, dispersion of substance, sterilization, emulsification, etc.) using this limit reaction field. Development of an ultrasonic treatment apparatus that performs the above-mentioned process is underway.

In addition, a plasma generator that generates plasma (sonoplasma) by superimposing a microwave on a cavitation generation region has been proposed (for example, Patent Document 1). If this apparatus is used, the temperature of the reaction field can be increased by generating plasma, and the reaction in the liquid is promoted.
JP 2003-297598 A

  By the way, Patent Document 1 does not specifically disclose the details of the microwave irradiation means in the plasma generator, and by analogizing from the detailed description of the invention and the description of the drawings, the microcavity is generated from the antenna in the cavitation generation region. It is thought that the structure which irradiates a wave is employ | adopted. In this apparatus, it is necessary to convert the microwave propagated through the waveguide into a high-frequency signal once by the antenna, and energy is lost during the conversion.

  Therefore, the inventors of the present application made a prototype of a novel plasma generator that directly irradiates microwaves from a waveguide to a cavitation generation region. As shown in FIG. 11, in the plasma generator 61, a waveguide 64 is disposed in a container 62 at a position facing the ultrasonic horn 63, and the tip of the waveguide 64 is placed in the liquid W. Yes. In this plasma generator 61, in order to achieve impedance matching with the liquid W, the inside of the waveguide 64 is filled with a dielectric (microwave transparent body) 65 such as quartz. Therefore, according to this apparatus, plasma can be generated more efficiently than the apparatus described in Patent Document 1, but on the other hand, there is a possibility that sufficient impedance matching cannot be obtained. That is, the tip of the microwave transmitting body 65 is a flat surface, and the impedance changes rapidly at the interface with the liquid W, and the microwave is reflected at the interface, so that the microwave irradiation efficiency is reduced. is there.

  FIG. 12 shows the electric field strength in the waveguide 64 and in the liquid W at the time of microwave irradiation. In FIG. 12, the vertical axis represents the electric field strength, and the horizontal axis represents the distance in the y direction with respect to the tip point O of the waveguide 64. As shown in FIG. 12, it can be seen that in the liquid W, the maximum electric field strength is attenuated to ¼ or less. In this case, the reflectance at the interface between the microwave transmission body 65 and the liquid W is 0.7, and it was confirmed that the microwave was reflected at this interface.

  The present invention has been made in view of the above problems, and an object thereof is to provide a plasma generator capable of efficiently irradiating microwaves from a waveguide onto a cavitation generation region in a liquid. is there.

  In order to solve the above problems, the invention described in claim 1 includes a container into which a liquid can be introduced, and an ultrasonic irradiation unit that irradiates ultrasonic waves into the liquid in the container to cause cavitation frequently. A microwave irradiating means for generating discharge plasma by propagating the microwave generated by the microwave generator through the waveguide and irradiating the cavitation generation region in the liquid from the tip of the waveguide; The waveguide has a tube body disposed so that a tip projects into the container, and a microwave transmission body disposed inside the tip of the tube body, the microwave transmission body The gist of the plasma generator is characterized in that a surface inclined with respect to the longitudinal direction of the tube body is formed at the tip of the tube.

  The invention according to claim 2 includes a container into which a liquid can be introduced, an ultrasonic irradiation means for irradiating ultrasonic waves into the liquid in the container to generate cavitation frequently, and a microwave generator. A microwave irradiation means for generating discharge plasma by propagating the generated microwave through the waveguide and irradiating the cavitation generation region in the liquid from the tip of the waveguide; Has a tube body arranged so that the tip projects into the container, and a microwave transmission body arranged inside the tip of the tube body, and the tip of the microwave transmission body is uneven. The gist of the plasma generator is that it is formed.

  According to the first and second aspects of the invention, the tip of the waveguide can be disposed near the cavitation generation region, and microwaves can be directly irradiated into the liquid from the waveguide. Further, as in the invention described in claim 1, an inclined surface is formed at the tip of the microwave transmission body, or asperities are formed in the tip of the microwave transmission body as in the invention of claim 2. By doing so, the impedance can be gently changed at the boundary between the microwave transmitting body and the liquid. If comprised in this way, reflection of the microwave in the front-end | tip part of a microwave permeation | transmission body can be suppressed, and discharge plasma can be generated efficiently. In addition, since the microwave transmission body is arranged inside the distal end of the waveguide, the microwave transmission body functions as a lid, so that liquid does not enter into the waveguide that protrudes into the container. Is prevented.

  The microwave transmitting body is preferably a dielectric (Claim 5), and specifically, it is preferably formed of a dielectric having a relative dielectric constant smaller than that of the liquid and larger than that of air. An example is quartz. Since quartz has the above-mentioned preferable properties, it can propagate microwaves efficiently. In addition, since quartz has relatively good processability, it is possible to relatively easily perform the process of forming the inclined surface and the unevenness, and the manufacturing cost of the microwave transmission body can be suppressed.

  According to a third aspect of the present invention, in the first or second aspect, the outer shape of the tube main body is a substantially circular shape, and the cross-sectional shape of the microwave transmitting body is a substantially rectangular shape. The gist of the invention is that a tube main body insertion hole for inserting the distal end of the waveguide is provided, and a seal member for sealing a gap between the tube main body insertion hole and the outer peripheral surface of the tube main body is provided. .

  According to invention of Claim 3, since the cross-sectional shape of a microwave permeation | transmission body is substantially rectangular shape, a microwave can be propagated efficiently. Also, since the outer shape of the tube body is substantially circular and does not have protrusions such as corners, the tube body and the tube body can be inserted by placing the seal member in contact with the outer peripheral surface of the tube body. The gap with the hole can be easily sealed.

  The gist of a fourth aspect of the present invention is that, in any one of the first to third aspects, it has a structure capable of changing a protruding amount of the tube main body into the container.

  According to the fourth aspect of the present invention, it is possible to adjust the microwave irradiation position (standing wave position) with respect to the cavitation generation region, and to efficiently generate discharge plasma.

  As described above in detail, according to the first to fifth aspects of the present invention, it is possible to provide a plasma generator capable of efficiently irradiating microwaves from a waveguide onto a cavitation generation region in a liquid. it can.

  Hereinafter, an embodiment in which the present invention is embodied in a plasma generator will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a plasma generator 11 according to the present embodiment, and FIG. 2 is a cross-sectional view of a main part of the plasma generator 11.

  As shown in FIG. 1, the plasma generator 11 includes a container 12 into which a liquid can be introduced, an ultrasonic generator 13, a microwave generator 14, a position adjusting device 15, a neutron irradiation device 16, a neutron counter 17, and a bubbling device. 18, a heat exchanger 19, and a control device 20.

  The control device 20 is constituted by a known microcomputer including a CPU, a ROM, a RAM, an input / output port, and the like. The control device 20 is electrically connected to the ultrasonic generator 13, the microwave generator 14, the position adjusting device 15, the neutron irradiation device 16, the neutron counter 17, the bubbling device 18, and the heat exchanger 19, The entire plasma generator 11 is comprehensively controlled by executing various processes.

  In the present embodiment, the container 12 is made of stainless steel, and the liquid W is placed in the container 12. Any liquid W can be selected according to the purpose.

  The ultrasonic generator 13 as the ultrasonic irradiation means includes a transducer 21 and a pulse generator 22 that outputs a pulse for driving the transducer 21. As shown in FIG. 2, the transducer 21 includes a vibrator 23 and a horn (resonator) 24. The outer peripheral surface of the horn 24 of the transducer 21 is fixed to the upper surface of the container 12 using a fixing member 25, and the tip of the horn 24 is placed in the liquid W.

  When the vibrator 23 is driven by the pulse output from the pulse generator 22, the transducer 21 irradiates the liquid W with, for example, an ultrasonic wave of 20 kHz and 0 to 1 kW from the tip of the horn 24. In the present embodiment, a protective plate 26 made of ceramic is provided at the tip of the horn 24 in order to prevent wear associated with the irradiation of ultrasonic waves.

  As shown in FIG. 1, a microwave generator 14 as a microwave irradiation means includes a magnetron (microwave generator) 28 that generates a microwave, and a waveguide that propagates the microwave generated by the magnetron 28 ( Microwave horn) 29, and is placed on the position adjusting device 15. The waveguide 29 of the microwave generator 14 is disposed on the bottom surface of the container 12 so as to face the transducer 21 of the ultrasonic generator 13. In the microwave generator 14, the magnetron 28 generates a microwave of 2.45 GHz, 0 to 1.8 kW, for example, when supplied with a direct current. The waveguide 29 propagates the microwave in the TE01 mode, which is the fundamental mode, and directly irradiates the liquid W from the tip.

  As shown in FIG. 2, the neutron irradiation device 16 is arranged so as to face the neutron transmission part 40 provided on the side surface of the container 12. The neutron irradiation device 16 converts a charged particle beam generated by an ion generation source (not shown) into a neutron beam having no charge, and then outputs the neutron beam toward the inside of the container 12. In addition, the neutron transmission part 40 is formed using the member (for example, glass plate) etc. which are easy to permeate | transmit a neutron rather than the stainless steel which comprises the container 12. FIG. Depending on the application, the neutron irradiation device 16 may not be used.

  As shown in FIG. 1, a neutron counter 17 for detecting the amount of neutrons is provided in the vicinity of the container 12. The neutron counter 17 is used for detecting the amount of neutrons in the container 12. As the neutron counter 17, a conventionally known neutron measuring instrument (for example, an ionization chamber, a proportional counter, a GM counter, etc.) can be used. Depending on the application, the neutron counter 17 may not be used.

  The bubbling device 18 includes a gas cylinder 41 filled with argon gas as a rare gas, a supply pipe 42 for supplying the argon gas into the liquid W, and an opening / closing valve 43 provided in the middle of the supply pipe 42. . In the bubbling device 18, the open / close valve 43 is operated in an open state, whereby the argon gas in the gas cylinder 41 is supplied into the liquid W through the supply pipe 42.

  As shown in FIG. 2, when argon gas is bubbled in the liquid W, air and the like contained in the liquid W are removed. In addition, bubbling argon gas into the liquid W causes frequent cavitation due to ultrasonic irradiation and facilitates generation of discharge plasma due to microwave irradiation.

  The heat exchanger 19 is provided on the side surface or bottom surface of the container 12 for cooling the cooling pipe 45 for circulating the cooling water, the liquid pump 46 provided in the middle of the cooling pipe 45, and a temperature for detecting the temperature of the liquid W. A thermocouple 47. In the heat exchanger 19, when the liquid pump 46 is driven based on the temperature detected by the thermocouple 47, the circulation of the cooling water in the cooling pipe 45 is started, and the temperature of the liquid W becomes a predetermined temperature or less. To be cooled.

  A viewing window (not shown) is provided on the side surface of the container 12 so that its internal state can be visually observed. Observation of sonoluminescence generated during irradiation with ultrasonic waves and observation of sonoplasma generated during irradiation with microwaves are provided. Is possible.

  Next, the structure of the waveguide 29 in the present embodiment will be described in detail. FIG. 3 is a cross-sectional view taken in a direction perpendicular to the longitudinal direction at a position slightly proximal to the distal end of the waveguide 29.

  As shown in FIGS. 2 and 3, the waveguide 29 is arranged in a tube main body 31 arranged so that the tip protrudes into the container 12, and inside the tip of the tube main body 31 (central hole 31 a). And a microwave transmission body (specifically, quartz) 32. The microwave transmitting body 32 is made of a dielectric material other than quartz (for example, a dielectric made of ceramics), and has a relative dielectric constant larger than 1 of air and smaller than that of the liquid W. Can be used.

  The tube body 31 is formed so that the outer shape is substantially circular, and the center hole 31a is formed so that a cross section cut in a direction orthogonal to the longitudinal direction of the tube body 31 is substantially rectangular. . The distal end of the tube body 31 is inserted into a tube body insertion hole 33 provided in the center of the bottom surface of the container 12. An O-ring (seal member) 34 that seals the gap between the tube body insertion hole 33 while being in contact with the outer peripheral surface is disposed at a position slightly proximal to the distal end of the tube body 31. ing. A ring-shaped fixing member 35 is provided at a position where the O-ring 34 is present on the outer peripheral surface of the tube body 31. The fixing member 35 compresses the O-ring 34 to reduce its diameter, and fixes the tube body 31 to the bottom surface of the container 12. In the present embodiment, the position adjusting device 15 is driven with the fixing member 35 removed, and the position of the waveguide 29 is appropriately adjusted along the longitudinal direction. Thereafter, by fixing the tube body 31 again with the fixing member 35, the protruding amount of the tube body 31 with respect to the bottom surface of the container 12 can be changed.

  As shown in FIGS. 2 to 4, the microwave transmission body 32 has a substantially rectangular cross-sectional shape cut in a direction orthogonal to the longitudinal direction of the tube body 31, and the tip thereof has a wedge shape (specifically, V By being cut into a groove shape, a surface (tapered surface) 36 that is inclined with respect to the longitudinal direction (vertical direction in FIG. 2) of the tube main body 31 is formed. Thus, by forming the tapered surface 36 at the tip of the microwave transmission body 32, the impedance of the microwave transmission body 32 with respect to the liquid W is matched. The proximal end side of the microwave transmission body 32 is processed so as to protrude in a wedge shape, and impedance matching with the air in the waveguide 29 is taken. The processing of the microwave transmitting body 32 is performed using a known method such as cutting, and the processed microwave transmitting body 32 is inserted into the tube body 31 to form the waveguide 29. In the present embodiment, a mechanical technique called cutting is employed, but a chemical technique such as etching may be used.

  In this way, by forming the tapered surface 36 at the tip of the microwave transmission body 32, the impedance changes gently at the boundary between the microwave transmission body 32 and the liquid W, and the Microwave reflection is suppressed.

  Specifically, the inventors of the present application simulate the relationship between the reflectance of the microwave and the cutting amount d1 of the tip when the cutting amount d1 (see FIG. 5) of the tip of the microwave transmission body 32 is changed. I tried to. The result is shown in FIG. As shown in FIG. 6, the reflectance of the microwave decreases as the cutting amount d1 at the tip of the microwave transmitting body 32 increases. Therefore, the microwave can be efficiently irradiated into the liquid W by forming the tapered surface 36 on the microwave transmitting body 32.

  Next, an operation example of the plasma generator 11 in the present embodiment will be described.

  First, the control device 20 operates the open / close valve 43 in the bubbling device 18 to open, and supplies the argon gas from the gas cylinder 41 into the liquid W through the supply pipe 42. Thereby, bubbling of argon gas in the liquid W is started.

  And the control apparatus 20 outputs a control signal to the ultrasonic generator 13, and starts irradiation of an ultrasonic wave. That is, in the pulse generator 22, a pulse is generated at a timing synchronized with a control signal from the control device 20, and the pulse is supplied to the transducer 21, so that the ultrasonic wave is irradiated from the transducer 21 into the liquid W. . Cavitation occurs frequently in the liquid W due to the irradiation of the ultrasonic waves.

  Thereafter, the control device 20 outputs a control signal to the microwave generator 14 to start microwave irradiation. Specifically, a microwave is generated by supplying a direct current to the magnetron 28 based on a control signal from the control device 20. Then, the microwave propagates through the waveguide 29 and is irradiated to the cavitation generation region R (see FIG. 2) in the liquid W through the microwave transmission body 32. Here, since the tapered surface 36 is formed in the microwave transmission body 32 of the present embodiment and the impedance changes gently at the boundary with the liquid W, the microwave is efficiently irradiated to the cavitation generation region R. The irradiation generates discharge plasma, and the temperature of the region (discharge plasma generation region) R is increased.

  Next, the control device 20 outputs a control signal to the neutron irradiation device 16 to start neutron irradiation. At this time, when the discharge plasma generation region R is irradiated with neutrons, deuterium contained in the liquid W is excited, and the temperature of the discharge plasma is further increased. Neutrons in the container 12 are counted by the neutron counter 17, and the control device 20 captures the detection signal. The control device 20 performs predetermined processing based on the detection signal, and displays predetermined information on a display device (display) (not shown). Note that neutron irradiation and counting may not be performed if unnecessary.

  Further, the control device 20 takes in the detection signal of the thermocouple 47 and determines whether or not the liquid temperature corresponding to the detection signal is equal to or higher than a predetermined temperature. And when it determines with liquid temperature being more than predetermined temperature, the heat exchanger 19 is operated. That is, the control device 20 drives the liquid pump 46 to circulate cooling water through the cooling pipe 45 to cool the liquid W. When the temperature of the liquid W decreases and it is determined that the liquid temperature is equal to or lower than the predetermined temperature based on the detection signal of the thermocouple 47, the control device 20 stops the heat exchanger 19 (liquid pump 46). In this way, by controlling the heat exchanger 19, it is possible to prevent the liquid W in the container 12 from becoming high temperature and causing cavitation to become unstable.

  Therefore, according to the present embodiment, the following effects can be obtained.

  (1) The plasma generator 11 of the present embodiment is configured to directly irradiate the microwave from the waveguide 29 into the liquid W. Therefore, compared with a plasma generator that outputs a microwave via an antenna, a uniform microwave can be irradiated to a wide region, and the size of the plasma generation region R can be sufficiently secured. Further, since the tapered surface 36 is formed at the tip of the microwave transmission body 32, the impedance can be changed gently at the boundary between the microwave transmission body 32 and the liquid W, and the tip of the microwave transmission body 32. The reflection of the microwave at the part can be suppressed. Therefore, microwaves can be efficiently irradiated and discharge plasma can be generated reliably.

  (2) In the case of the present embodiment, quartz is used as the microwave transmission body 32 and the tip portion thereof is cut into a wedge shape to form the tapered surface 36. Since quartz is a material having a relative dielectric constant smaller than that of the liquid W and larger than that of air, the microwave transmission body 32 capable of efficiently transmitting microwaves can be obtained. Further, since quartz has a relatively good processability, it is possible to relatively easily process the tip portion into a wedge shape, and the manufacturing cost of the microwave transmission body 32 can be suppressed.

  (3) In the case of the present embodiment, since the cross-sectional shape of the microwave transmission body 32 is substantially rectangular, microwaves can be propagated efficiently. Further, since the outer shape of the tube body 31 is substantially circular and does not have protrusions such as corners, the tube body 31 is arranged by placing the O-ring 34 in contact with the outer peripheral surface of the tube body 31. And the tube main body insertion hole 33 can be easily sealed.

  (4) In the plasma generator 11 of the present embodiment, the microwave generator 14 is provided on the position adjustment device 15, and the position adjustment device 15 is driven to reduce the amount of protrusion of the tube body 31 into the container 12. Can be changed. In this case, the microwave irradiation position (standing wave position) with respect to the cavitation generation region R can be adjusted, and discharge plasma can be generated efficiently.

  (5) In the plasma generator 11 according to the present embodiment, the transducer 21 of the ultrasonic generator 13 and the waveguide 29 of the microwave generator 14 are arranged to face each other, and thus generated by irradiation with ultrasonic waves. The microwave can be reliably irradiated to the cavitation generation region R, and a sufficient amount of plasma (sonoplasma) can be generated to form a reaction field.

  (6) In the plasma generator 11 of the present embodiment, since argon gas is bubbled into the liquid W, cavitation occurs frequently and efficiently, and the discharge plasma generation region can be easily expanded. Further, since the liquid W is cooled by the heat exchanger 19, cavitation is stably generated. As a result, the temperature of the discharge plasma generation region R can be further increased.

  In addition, you may change embodiment of this invention as follows.

  -In this Embodiment, although the front-end | tip of the microwave permeation | transmission body 32 was processed into concave shape and the taper surface 36 was formed, it is not limited to this. As shown in FIG. 7, the tapered surface 52 may be formed by processing the tip of the microwave transmitting body 51 so as to protrude in a wedge shape. In the microwave transmission body 51, the relationship between the reflectance of the microwave and the cutting amount d2 at the tip when the cutting amount d2 at the tip was changed was simulated. The result is shown in FIG. As shown in FIG. 8, the reflectance of the microwave decreases as the cutting amount d2 at the tip of the microwave transmitting body 51 increases. Therefore, also in this microwave transmission body 51, the microwave can be efficiently irradiated into the liquid W by forming the tapered surface 52 at the tip thereof.

  Further, an uneven portion may be formed at the tip portion as in the microwave transmitting body 53 shown in FIG. 9, and a spherical concave portion is formed in the tip portion as in the microwave transmitting body 54 shown in FIG. It may be formed. Of course, a conical or pyramidal concave or convex portion may be formed at the tip of the microwave transmitting body. In addition, the concave portion or the convex portion formed at the tip of the microwave transmitting body may be one or plural. In this way, by forming the microwave transmission bodies 53 and 54, the impedance can be gradually changed at the boundary between the microwave transmission bodies 53 and 54 and the liquid W, and the microwave is efficiently contained in the liquid W. Can be irradiated. However, the microwave transmission body 32 of the above-described embodiment having a simple tip shape as compared with these and the microwave transmission body 51 of FIG. 7 are advantageous in terms of easy processing.

  In the plasma generator 11 of the above embodiment, one pair of the ultrasonic generator 13 and the microwave generator 14 is provided, but a plurality of pairs may be provided. Even in this case, the size of the plasma generation region R can be sufficiently secured, and acoustic fusion can be caused in a wide range.

  In the plasma generator 11 of the above embodiment, the transducer 21 of the ultrasonic generator 13 is disposed on the top surface of the container 12 and the waveguide 29 of the microwave generator 14 is disposed on the bottom surface of the container 12. However, conversely, the transducer 21 may be disposed on the bottom surface of the container 12 and the waveguide 29 may be disposed on the top surface of the container 12.

  In the plasma generator 11 of the above embodiment, the microwave generator 14 is arranged on the position adjusting device 15 and the position of the waveguide 29 of the microwave generator 14 can be changed. The position adjustment device 15 may be provided on the device 13 side so that the position of the transducer 21 can be changed.

  -The plasma generator 11 of the said embodiment can also be utilized as a nuclear fusion apparatus which raises acoustic fusion (sonofusion), for example. Of course, in addition to being used as such an apparatus, the plasma generator 11 can be used as a reaction apparatus for inducing and promoting a chemical reaction (for example, an apparatus for generating carbon nanoparticles, carbon nanotubes, amorphous carbon, etc.), sewage, etc. It can also be used as a processing device for decomposing harmful substances contained in water. In this case, the neutron irradiation device 16 and the neutron counter 17 in the plasma generator 11 can be omitted.

  In the plasma generator 11 of the above-described embodiment, a passage for introducing the liquid W to the container 12 (introduction path and discharge path for the liquid W) is connected, and the chemical reaction process while flowing the liquid W through the container 12 is performed. It can also be configured to perform treatment such as sewage treatment. In this case, the processing may be continuous processing or discontinuous processing (so-called batch processing).

  In the plasma generator 11 of the above embodiment, the frequency of the ultrasonic wave irradiated by the ultrasonic wave generator 13 is 20 kHz, and the microwave irradiated by the microwave generator 14 is 2.45 GHz. May be changed as appropriate. For example, the ultrasonic frequency may be set higher, specifically, about 100 kHz to 500 kHz.

  -Although the cross-sectional shape cut | disconnected in the direction orthogonal to the longitudinal direction of the pipe | tube main body 31 was substantially rectangular shape, the microwave transmission body 32 of said embodiment was shapes (for example, substantially circular shape) other than a substantially rectangular shape. It may be.

  The microwave transmitting body 32 in the plasma generator 11 of the above embodiment has a surface (tapered surface 36) inclined with respect to the longitudinal direction of the tube main body 31 at the tip, but this is replaced. Therefore, it is acceptable to use the microwave transmission body 65 shown in FIG. There is no inclined surface at the tip of the microwave transmitting body 65, and instead, a flat surface perpendicular to the longitudinal direction of the tube body 31 is formed. And although it does not reach the microwave transmission body 32 of the said embodiment, according to the microwave transmission body 65 shown in FIG. 11, rather than the microwave irradiation means in the plasma generator described in patent document 1, it is microwave. Can be efficiently irradiated, and plasma can be generated efficiently.

  Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the embodiment described above are listed below.

  (1) The plasma generator according to any one of claims 1 to 4, wherein the liquid contains deuterium and / or tritium, and is used as a nuclear fusion device for causing nuclear fusion. .

  (2) The plasma generator according to any one of claims 1 to 4, wherein the microwave transmitting body is made of quartz.

  (3) The plasma generator according to claim 1, wherein a tip portion of the microwave transmitting body is formed in a wedge shape.

  (4) The method according to any one of claims 1 to 4, further comprising a control unit that is electrically connected to the ultrasonic irradiation unit and the microwave irradiation unit and controls each of the units. Plasma generator.

  (5) A container into which a liquid can be introduced, ultrasonic irradiation means for generating cavitation frequently by irradiating the liquid in the container with ultrasonic waves, and a microwave generated by the microwave generator as a waveguide And a microwave irradiation means for generating discharge plasma by irradiating the cavitation generation region in the liquid from the tip of the waveguide, and the waveguide has a tip in the container. A plasma generator comprising: a tube main body arranged so as to protrude; and a microwave transmitting body made of a dielectric disposed inside a tip of the tube main body.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram which shows the plasma generator of one Embodiment which actualized this invention. FIG. 2 is a main part sectional view showing the plasma generating apparatus of FIG. 1. Sectional drawing which shows a waveguide. The perspective view which shows a microwave transparent body. Sectional drawing which shows the amount of cutting of a microwave transmission body. The graph which shows the relationship between the amount of shavings and a reflectance. Sectional drawing which shows the amount of cutting of the microwave transmission body of another embodiment. The graph which shows the relationship between the amount of shavings and a reflectance. Sectional drawing which shows the microwave transmission body of another embodiment. Sectional drawing which shows the microwave transmission body of another embodiment. Sectional drawing which shows the principal part which shows the plasma generator which is a prototype. The graph which shows the electric field strength in a waveguide and in a liquid.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Plasma generator 12 ... Container 13 ... Ultrasonic generator as ultrasonic irradiation means 14 ... Microwave generator as microwave irradiation means 28 ... Magnetron as microwave generator 29 ... Waveguide 31 ... Tube main body 32, 51, 53, 54 ... microwave transmitting body 33 ... tube body insertion hole 34 ... O-ring as sealing member 36, 52 ... taper surface R ... cavitation generation region W ... liquid

Claims (5)

A container into which a liquid can be introduced;
Ultrasonic irradiation means for irradiating ultrasonic waves into the liquid in the container to cause multiple cavitations;
A microwave irradiation means for generating discharge plasma by propagating the microwave generated by the microwave generator through the waveguide and irradiating the cavitation generation region in the liquid from the tip of the waveguide; ,
The waveguide has a tube main body arranged so that a tip protrudes into the container, and a microwave transmitting body arranged inside the tip of the pipe main body, and the tip of the microwave transmitting body The plasma generator is characterized in that a surface inclined with respect to the longitudinal direction of the tube main body is formed in the part. A container into which a liquid can be introduced;
Ultrasonic irradiation means for irradiating ultrasonic waves into the liquid in the container to cause multiple cavitations;
A microwave irradiation means for generating discharge plasma by propagating the microwave generated by the microwave generator through the waveguide and irradiating the cavitation generation region in the liquid from the tip of the waveguide; ,
The waveguide has a tube main body arranged so that a tip protrudes into the container, and a microwave transmitting body arranged inside the tip of the pipe main body, and the tip of the microwave transmitting body A plasma generator characterized in that the surface is uneven. The outer shape of the tube body is a substantially circular shape, and the cross-sectional shape of the microwave transmitting body is a substantially rectangular shape,
The container is provided with a tube main body insertion hole into which the distal end of the waveguide is inserted, and a seal member that seals a gap between the tube main body insertion hole and the outer peripheral surface of the tube main body. The plasma generator according to claim 1 or 2, characterized by the above.   The plasma generator according to any one of claims 1 to 3, wherein the plasma generator has a structure capable of changing a protruding amount of the tube main body into the container.   The plasma generator according to any one of claims 1 to 4, wherein the microwave transmission body is a dielectric.

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