High-power pulse generator

Abstract

To provide a high-output pulse generating device which can be transported by a truck or the like by reducing its size and weight as compared with a conventional one while being capable of generating an ultra-high-output ultra-short pulse having a few outputs GW and a pulse width of a 100ns level.SOLUTION: A high-output pulse generator according to the present invention includes an input port connected to a power supply, an output port connected to a load, and an electrode pair 24 including a linear inner conductor 22 provided in a main body 21 and connecting the input port and the output port, and a cylindrical outer conductor 23 disposed around the inner conductor with a gap therebetween, wherein the electrode pair 24 is formed by being folded back at least once in the main body 21.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a high-power pulse generator for outputting ultra-high-power, extremely short pulses with an output power of several gigawatts (GW) and a pulse width of 100 ns. [Background technology]

[0002] Extreme Impulse Generation Systems (EIGS) with output power of several gigawatts and pulse widths of 100 nanoseconds are used in a wide range of applications, including nondestructive testing of various structures, voltage testing, arc resistance testing, surge testing of electronic components, noise malfunction countermeasures, core pulse characteristic measurement, material analysis, cancer treatment in the medical, health, and nursing fields, semiconductor lithography thin film deposition in the manufacturing equipment field, semiconductor manufacturing, lasers, wastewater and exhaust gas purification, E. coli sterilization, and engine combustion promotion in the environmental and energy fields, and high-power microwaves, plasma generation, neutron generation, accelerators, nuclear fusion, and electron and ion beam applications in research and development. In these fields, EIGS can be used to generate high-energy, ultrashort-duration ion beams, electron beams, and X-ray beams, enabling advanced research, inspection, testing, and manufacturing. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] "Nagaoka University of Technology Extreme Energy-Density Engineering Research Center High-Intensity Pulsed Power Generator (ETIGO-II)", [online], [Retrieved July 20, 2024], Internet<https: / / etigo.nagaokaut.ac.jp / machine / etigo_2.html> [Non-patent document 2] "High Repetition Rate Pulsed Power Generator (ETIGO-IV) at the Extreme Energy-Density Engineering Research Center, Nagaoka University of Technology", [online], [Retrieved July 20, 2024], Internet<https: / / etigo.nagaokaut.ac.jp / machine / etigo_4.html> Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, power supplies for generating such ultra-high power, ultra-short pulses required devices with external dimensions (length) of several meters and masses of several tons (Non-Patent Documents 1 and 2). Such power supply devices could only be used as stationary devices, which significantly limited the targets for non-destructive testing, for example.

[0005] The problem that the present invention aims to solve is to provide a high-power pulse generator that is capable of generating ultra-high-power, extremely short pulses with an output power of several gigawatts and a pulse width of 100 ns, while being smaller and lighter than conventional devices, making it possible to transport it by truck, etc. [Means for solving the problem]

[0006] The high-power pulse generator according to the present invention, which has been made to solve the above problems, is A high-power pulse generator having an input port connected to a power source and an output port connected to a load, the high-power pulse generator including an electrode pair provided within a main body and including a linear inner conductor connecting the input port and the output port, and a cylindrical outer conductor disposed around the inner conductor with a gap therebetween, The electrode pair is characterized in that it is formed by folding back at least once within the main body.

[0007] In conventional high-power pulse generators, a right-cylindrical metallic external electrode is installed inside the main body. A linear (rod-shaped) metallic internal electrode is placed at the center of the external electrode, forming a pulse-forming line (PFL) filled with a dielectric (usually pure water or insulating oil) between the two electrodes. This external electrode is grounded, and a high voltage is applied to the internal electrode to charge it. The output side connected to the internal electrode is then connected to a load via a switch, generating a high-power short pulse. To achieve a pulse output power of several gigawatts and stably achieve this for a period of approximately 100 nanoseconds, the length of the PFL must be several meters. This necessitates a conventional high-power pulse generator with an external dimension (length) of several meters and a mass of several tons (for example, the ETIGO-IV described in Non-Patent Document 2 has a total length of 3900 mm, width of 1100 mm, height of 2700 mm, and mass of 4000 kg).

[0008] On the other hand, in the high-power pulse generator according to the present invention, the electrode pair consisting of the inner conductor and the outer conductor is not formed in a straight cylindrical shape, but is formed by folding back at least once inside the main body. This allows the outer shape (length) of the main body to be reduced in size by the number of folds (in principle, 1 / 2 for one fold, and 1 / (N+1) for N folds). This also results in a reduction in weight. Note that while it is desirable for the folds to be parallel to the unfolded and folded portions, zigzag folds with a slight angle (of about 30° or less) are also acceptable. The shape of the folded portions may be semicircular (arcuate) or U-shaped.

[0009] For reference, an example of a single fold is shown in Figure 1, and an example of a double fold is shown in Figure 2. In both cases, electrode pairs 14, 24, consisting of inner conductors 12, 22 and outer conductors 13, 23, are folded back inside main body 11, 21. Note that if the fold is made an odd number of times, the input port and output port will be on the same side of main body 11, as shown in Figure 1, which will complicate the electrical system on that side and cause interference. For this reason, it is desirable to fold back an even number of times, with the input port and output port separated into opposite sides, as shown in Figure 2.

[0010] In another embodiment of the present invention, an electrode pair consisting of an inner conductor and an outer conductor may be formed in a three-dimensional spiral shape within the body.

[0011] Here, a "three-dimensional spiral shape" does not refer to a spiral on a two-dimensional plane, but rather to a shape in three-dimensional space in which one end and the other end are connected by a curve rather than a straight line. Typically, this refers to a helical shape like a coil spring, as shown in Figure 3, but it can also be a single or fewer revolution. Even if there are multiple revolutions, the diameters do not necessarily have to be the same. Furthermore, there may be a partial receding portion as the shape moves from one end to the other.

[0012] In both of the above-described high-power pulse generators, the main body can be made of a (bulk) metal such as copper, aluminum, or stainless steel, and the external electrode can be the inner surface of a folded or three-dimensional spiral cylindrical cavity (not a right cylindrical cavity, but a circular cavity in each cross section that maintains an equidistant space around the central axis = internal electrode) formed inside the main body. The internal electrode is provided on the central axis of the cavity.

[0013] In the high-power pulse generators of both of the above aspects, the main body may be made of insulating resin, and the external electrode may be a conductor coated on the inner surface of the cavity, which has a folded or three-dimensional spiral shape formed inside the main body. The internal electrode is provided on the central axis of the cavity. The conductor coated on the inner surface of the cavity may be a metal film such as a copper film or a nickel film formed by electrodeposition or the like.

[0014] In order to maintain the gap between the external electrode and the internal electrode at an equal distance, an insulating support member can be installed between the external electrode and the internal electrode, thereby enabling stable output. [Effects of the Invention]

[0015] In the high-power pulse generator of the present invention, the electrode pair is formed by folding back at least once inside the main body, so the overall length of the main body can be made shorter than that of a conventional straight cylindrical body while maintaining the overall length of the electrode pair, making the entire device smaller and lighter. Conversely, if the overall length of the main body is kept approximately the same as that of a conventional straight cylindrical body, the overall length of the electrode pair can be made longer, allowing for the generation of pulses with a longer duration. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view of an example of the configuration of a one-fold high-power pulse generator. [Figure 2] FIG. 1 is a perspective view of an example of the configuration of a two-fold high-power pulse generator. [Figure 3] FIG. 1 is a perspective view of a configuration example of a helical-shaped high-power pulse generator. [Figure 4] 1 is an electrical configuration diagram of an ultra-high power extremely short pulse power supply system (EIGS) according to one embodiment of the present invention. [Figure 5] FIG. 2 is a perspective view of the appearance of the folded waveform shaping line (PFL) of the EIGS. [Figure 6] An oblique view of the exterior of the PFL with the input side exterior section removed. [Figure 7] An external perspective view of the PFL with the input side and central exterior section removed. [Figure 8] FIG. 1 is a perspective view showing only the inner conductor of a PFL. [Figure 9] A cross-sectional view of a PFL at a location where an insulating support member is installed over the internal conductor. DETAILED DESCRIPTION OF THE INVENTION

[0017] An ultra-high power, extremely short pulse power supply system (EIGS) according to one embodiment of the present invention will be described with reference to Figs. 4 to 9. First, Fig. 4 shows the electrical configuration of an EIGS 40 according to this embodiment. This EIGS 40 is broadly divided into two sections: a front-stage voltage pulse charging section 41 and a rear-stage high-voltage pulse generating section 42. The front-stage voltage pulse charging section 41 employs a battery-driven power supply and a Tesla transformer 43 for front-stage voltage step-up. The rear-stage high-voltage pulse generating section 42 employs a folded waveform shaping line 44.

[0018] The folded PFL 44 used in this EIGS 40 has the configuration according to the present invention, with four folds. That is, inside the main body 45, the capacitor electrode pairs are composed of five parallel straight paths and four folded paths connecting them.

[0019] As shown in Figure 5, the main body 45 is cylindrical, with a total length of 400 mm and a diameter of approximately 300 mm. The main body 45 is divided into three sections along its length: a first section 46 on the input side, a third section 48 on the output side, and a central second section 47 sandwiched between them. Five parallel electrode pairs (five sets) are formed inside the second section 47, and two return paths (U-turn paths) are formed inside the first section 46 and the third section 48 for returning four of the electrode pairs (four sets). This division facilitates the formation of a return cavity for the external conductor 50 within the main body 45.

[0020] Fig. 6 is a perspective view of the state where the outer structure portion of first section 46 (this is the name given to the portion other than the cavity) has been removed, Fig. 7 is a perspective view of the state where the outer structure portions of first section 46 and second section 47 have been removed, and Fig. 8 is a perspective view of the state where all of the outer structure portions of first section 46, second section 47, and third section 48 have been removed, leaving only internal conductor 51. Internal conductor 51 can also be easily manufactured by separately forming straight sections and bent sections corresponding to first section 46 to third section 48 of main body 45, and then connecting and assembling them.

[0021] In this embodiment, the PFL 44's exterior is made of ABS resin, and the first, second, and third sections 46, 47, and 48 are molded from resin using a mold. These sections may also be manufactured using a 3D printer. As shown in Figures 6 and 7, the outer conductor 50 is formed by copper plating on the inner surface of a cylindrical cavity formed around the inner conductor 51 with a gap of approximately 27 mm. Because the PFL 44 handles extremely short pulses for both input and output, the skin effect causes current to flow almost exclusively on the surface. Therefore, a film-like electrode formed on the inner surface of the cavity can be adequately used for the outer conductor 50. Furthermore, by using resin for the exterior of the main body 45, the overall device weight can be significantly reduced. The inner conductor 51 is made of copper wire with a diameter of 16 mm. The interior of the cavity, i.e., the space between the outer conductor 50 and the inner conductor 51, is filled with pure water, a dielectric.

[0022] In order to accurately position the inner conductor 51 at the center of the outer conductor 50 and hold it in that position, an insulating support member 53 is provided at one location on each of the five straight paths inside the second section 47 of the main body 45, as shown in Fig. 9. Since the insulating ability of the support members 53 decreases at the locations supported by the support members 53, the cavity 52 is formed into a cone shape so as to increase the distance between the inner conductor 51 and the outer conductor 50. Both ends of the support member 53 are fixed to an exterior section 54 (made of ABS resin) of the main body 45 (second section 47), and the support member 53 holds the inner conductor 51 in the center.

[0023] The EIGS 40 of this embodiment, fabricated in this way, uses a DC 24V, 210A battery as input in the upstream voltage pulse charging unit 41, which charges a compact inverter charger with 5kW of power for 2μsec. The compact inverter charger converts this to 200MW of power and charges the PFL 44 over a 2μsec charging time. The PFL 44 then outputs this as an ultra-high-power, extremely short pulse with an output of 4GW and a pulse width of 100nsec.

[0024] In the PFL44 of this embodiment, the total length of the main body 45 is approximately 400 mm, but the folded structure allows the length of the internal conductor 51 (i.e., the electrode pair) to be 2071 mm, which makes it possible to store and output a sufficient amount of energy.

[0025] As described above, the EIGS 40 of this embodiment employs a coreless Tesla transformer 43 in the front stage and a folded PFL 44 in the rear stage, enabling it to be miniaturized to approximately 1500 mm in overall length and 300 mm in diameter. Furthermore, its weight is approximately 200 kg, and coupled with the use of a battery as the power source, it can now be transported by truck or other means and used on-site. This is expected to lead to rapid development of industrial applications for the following new downstream needs: (1) X-ray non-destructive inspection of buildings, bridges, tunnels, etc. (2) Electron beam sterilization of soil (3) Portable neutron source (for diagnosing deterioration of concrete infrastructure structures, analyzing raw materials and products in factories, etc.) (4) Establishment of various other security technologies (high-power pulse lasers, high-intensity microwaves), and expansion into new fields such as mobile nuclear material detection systems and ballast water treatment systems.

[0026] In addition, conventional (1) X-ray irradiation equipment for cancer treatment (2) Non-heating electric field sterilization equipment for food ingredients (3) Wastewater and exhaust gas treatment equipment using streamer discharge It is expected that the spread of these technologies will be promoted through miniaturization and cost reduction. [Explanation of symbols]

[0027] 40...Ultra-high power ultra-short pulse power supply system (EIGS) 41...Voltage pulse charging section 42...High voltage pulse generator 43...Tesla transformer 44...Folded Wave Forming Line (PFL) 45...Main body 46…Part 1 47…Part 2 48…Part 3 50...Outer conductor 51...Inner conductor 52...Cavity 53...Support member 54...Exterior section

Claims

1. A high-power pulse generator having an input port connected to a power source and an output port connected to a load, the high-power pulse generator including an electrode pair provided within a main body and including a linear inner conductor connecting the input port and the output port, and a cylindrical outer conductor disposed around the inner conductor with a gap therebetween, A high-power pulse generator characterized in that the electrode pair is formed by folding back at least once within the body.

2. A high-power pulse generator having an input port connected to a power source and an output port connected to a load, the high-power pulse generator including an electrode pair provided within a main body and including a linear inner conductor connecting the input port and the output port, and a cylindrical outer conductor disposed around the inner conductor with a gap therebetween, A high-power pulse generator characterized in that the electrode pair is formed in a three-dimensional spiral shape within the body.

3. 3. The high-power pulse generator according to claim 1, A high-power pulse generator characterized in that the main body is made of a metal body made of the same material as the outer conductor.

4. 3. The high-power pulse generator according to claim 1, A high-power pulse generator characterized in that the main body is made of insulating resin, the inner surface of which is coated with the outer conductor.

5. 3. The high-power pulse generator according to claim 1, A high-power pulse generator characterized in that the inner conductor is held in the electrode pair at the center axis of the outer conductor across the gap by an insulating support member bridged between the inner conductor and the outer conductor.

6. 3. The high-power pulse generator according to claim 1, A high-output pulse generator that uses a battery-powered charger as its power source.

7. 2. The high-power pulse generator according to claim 1, A high-power pulse generator characterized in that the main body is divided into an input port end, an output port end, and at least one intermediate section provided therebetween, and the electrode pair is folded back at the input port end and the output port end.

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