A tri-coaxial blumlein pulse forming line and method of use thereof

Abstract

The application discloses a three-coaxial Blumlein pulse forming line and an application method thereof, and the pulse forming line is arranged in a closed structure and has a cross section of a regular polygon, and is composed of a high-dielectric-constant flat ceramic transmission line and a coaxial conductor with a cross section of a regular polygon, and comprises, from inside to outside, an inner regular polygon conductor, an inner flat ceramic transmission line, a middle-layer regular polygon conductor, an outer flat ceramic transmission line and an outer regular polygon conductor; the inner regular polygon conductor, the inner flat ceramic transmission line and the middle-layer regular polygon conductor form an inner transmission line; and the outer regular polygon conductor, the outer flat ceramic transmission line and the middle-layer regular polygon conductor form an outer transmission line. The application can significantly reduce the volume and weight of a pulse power system, and obviously improve the quality of a pulse output waveform.

Description

Technical Field

[0001] This invention relates to the field of pulse power, specifically to a triaxial Blumein pulse forming line with a closed cross-section of a regular polygon and a method for applying the pulse forming line. Background Technology

[0002] In the field of high-power particle accelerators, pulsed power sources are indispensable. Typically, particle accelerator pulsed power sources require ultrafast high-peak power switches in combination with pulse forming lines to compress pulse energy and achieve high-quality square wave high-voltage output, thereby driving the particle accelerator to accelerate charged particle beams. It is evident that switches and pulse forming lines are key to the success or failure of developing high-power particle accelerators.

[0003] Common pulse forming lines mainly fall into two categories: coaxial pulse forming lines and planar pulse forming lines. Planar pulse forming lines, due to their open electrode structure, are often accompanied by electromagnetic leakage (radiation loss) during pulse formation, making them susceptible to interference from external electromagnetic signals. In contrast, coaxial cables have a completely enclosed electrode structure, with the electromagnetic field completely contained between the inner and outer conductors during pulse formation. There is no electromagnetic radiation loss, and they are not affected by external electromagnetic signals. Therefore, coaxial pulse forming lines produce better waveform quality than planar pulse forming lines. Especially in applications where flat-top ripples and variations in the pulse waveform are required, coaxial pulse forming lines are typically used to generate the necessary high-voltage pulses.

[0004] Coaxial pulse forming lines include steel cylinder pulse forming lines with water or oil as the medium, ranging from hundreds of kV to MV, as well as flexible cables with insulation media such as polyethylene, ranging from tens of V to hundreds of kV. Pulse power sources constructed using these devices are typically large and bulky. Therefore, the development of compact solid-state pulse power systems based on solid-state planar transmission line technology has been a research hotspot both domestically and internationally, especially the research on pulse power technology using stacked Blumlein pulse forming lines. This technology integrates high energy storage technology, transmission line technology, and switching technology, significantly reducing the size and weight of pulse power devices, and easily achieving miniaturization and compactness of pulse power systems.

[0005] However, due to the open electrode structure of the planar pulse transmission line, electromagnetic leakage (radiation loss) usually occurs during the transmission of electromagnetic waves. In particular, when using the planar pulse transmission line to construct the Blumlein pulse forming line, it is difficult to obtain a high-quality square wave output with flat-top ripple and small flat-top variation.

[0006] To address this issue, this application proposes a closed-structure triaxial Blumlein pulse forming line with a regular polygonal cross-section and its application method, which can significantly reduce the size and weight of the pulse power system while obtaining high-quality pulse high voltage waveforms, thus solving the aforementioned technical problems. Summary of the Invention

[0007] The main objective of this invention is to provide a three-coaxial Blumein pulse forming line and its application method. From the perspective of circuit topology, it consists of multiple flat Blumein pulse forming lines connected in parallel. From the perspective of geometric structure, it is a closed, symmetrical pulse forming line without electromagnetic leakage. Therefore, it can significantly reduce the size and weight of the pulse power source and significantly improve the output waveform quality of the pulse power source.

[0008] The present invention solves the above-mentioned technical problems by adopting the following technical solutions: A triaxial Blumein pulse forming line, wherein the pulse forming line is configured as a closed structure with a regular polygonal cross-section, the pulse forming line is composed of a high dielectric constant planar ceramic transmission line and a coaxial conductor with a regular polygonal cross-section, comprising: The inner regular polygonal conductor, the inner flat ceramic transmission line, the middle regular polygonal conductor, the outer flat ceramic transmission line, and the outer regular polygonal conductor are arranged sequentially from the inside to the outside. The inner flat ceramic transmission line and the outer flat ceramic transmission line have the same geometric dimensions and material parameters. The inner regular polygonal conductor, the inner flat ceramic transmission line, and the middle regular polygonal conductor constitute the inner transmission line of the Blumein pulse forming line. The outer regular polygonal conductor, the outer flat ceramic transmission line, and the middle regular polygonal conductor constitute the outer transmission line of the Blumullein pulse forming line.

[0009] Preferably, the inner regular polygonal conductor, the middle layer regular polygonal conductor, and the outer regular polygonal conductor all have the same polygonal shape, such as equilateral triangles, squares, regular pentagons, regular hexagons, and so on, and are all set to be regular. polygon, and ; Both the inner flat ceramic transmission line and the outer flat ceramic transmission line are equipped with The group fits along the edges of each regular polygon.

[0010] Preferably, the inner flat ceramic transmission line and the outer flat ceramic transmission line have the same relative permittivity, which is typically in the range of tens to thousands.

[0011] Preferably, the inner flat ceramic transmission line and the outer flat ceramic transmission line have the same length, width and thickness.

[0012] Preferably, the inner regular polygonal conductor, the middle regular polygonal conductor, and the outer regular polygonal conductor can be made of any one of copper, stainless steel, aluminum, etc.

[0013] On the other hand, the present invention also provides a method for applying a triaxial Blumlein pulse forming line, comprising: For any of the three coaxial Blumein pulse forming lines described above, a switch is connected at one end between the middle polygonal conductor and the outer polygonal conductor. The load is connected to the other end between the inner and outer regular polygonal conductors. This is used to construct the Blummlein pulse forming line circuit.

[0014] Preferably, the switch S connecting the middle regular polygonal conductor and the outer regular polygonal conductor can be one, two, or so on. One, even indivual, indivual,…….

[0015] Preferably, the load is connected between the inner regular polygonal conductor and the outer regular polygonal conductor. It can be 1, 2, and so on up to... One, but the load needs to be ensured. Parallel value and cross section normal Output impedance of triaxial Blumlein pulse forming line with a closed-loop structure Matching , where the load It can be one resistor, or two, three, and so on. The parallel resistors can also be pulse transmission line cables that match the output impedance. The output impedance can be designed according to actual needs, for a positive cross-section The closed-structure triaxial Blumlein pulse forming line with a polygonal shape, due to A flat ceramic transmission line is connected in parallel to the positive Along the side length of the polygon, its impedance is The parallel value of a flat ceramic transmission line has a positive cross-section. The specific formula for the output impedance of the triaxial Blumlein pulse forming line with a closed polygonal structure is as follows:

[0016] in, The characteristic impedance of a single flat ceramic transmission line; Through the cross section The closed-structure triaxial Blumlein pulse forming line with a polygonal shape is designed to output pulse width. The formula for the output pulse width is as follows:

[0017] in, This represents the pulse width output by the Blumlein pulse forming line across the load. The unidirectional propagation delay (electrical length) of electromagnetic waves in a single Blumlein transmission line. Ultimately, it meets the needs of different pulse power applications.

[0018] Preferably, considering the characteristic impedance of the planar ceramic transmission line and the number of sides of the regular polygon, the wave impedance between the outer regular polygon conductor and the middle regular polygon conductor is adjusted to 1-50Ω, and the wave impedance between the middle regular polygon conductor and the inner regular polygon conductor is adjusted to 1-50Ω.

[0019] Preferably, considering the geometric lengths of the ceramic dielectric and the flat ceramic transmission line, the electrical length of the Blumein pulse forming line is adjusted to 5-500 ns, so that the output pulse width of the Blumein pulse forming line is 10-1000 ns.

[0020] This invention provides a triaxial Blumlein pulse forming line and its application method. Compared with the prior art, the advantages of this invention are reflected in: 1. This invention can significantly reduce the size and weight of the pulse power system while obtaining a high-quality pulse high-voltage output. That is, compared with the cable pulse forming line of the same voltage level, it can significantly reduce the size and weight of the pulse power source; compared with the ceramic solid pulse forming line of the same voltage level, it can significantly improve the quality of the pulse output waveform. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram showing the structural breakdown of the three coaxial Blumlein pulse forming line of the present invention, taking a regular quadrilateral shape as an example; Figure 2 This is a perspective view of the structure of the three coaxial Blumlein pulse forming lines of the present invention; Figure 3 This is an example diagram of the pulse output waveform of the three coaxial Blumlein pulse forming line of the present invention; Figure 4This is a comparison diagram of the simulated output pulse waveforms of the three-coaxial Blumlein pulse forming line and the flat Blumlein pulse forming line of this invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] For details in the embodiments, please refer to Figures 1 to 3 .

[0024] For commonly used technologies in the present invention The characteristic impedance of a flat transmission line. and electrical length They are respectively represented as

[0025]

[0026] In the formula, For flat panel transmission line spacing, For the width of the flat panel transmission line, The geometric length of the flat transmission line is... The relative permittivity, The permeability of the medium, The speed of light in a vacuum; Planar ceramic transmission lines with the same geometry and material parameters (dielectric constant and permeability) have the same characteristic impedance and electrical length.

[0027] To address this, the present invention provides a triaxial Blumein pulse forming line. Based on the analysis of the prior art, multiple planar ceramic transmission lines with the same electrical parameters can be connected in parallel along the side length of a regular polygonal conductor in this triaxial Blumein pulse forming line, thereby further forming a solid-state Blumein pulse forming line. This line features low output impedance and compact size, making it extremely easy to achieve compact miniaturization and solid-state lightweighting of pulse power sources. Furthermore, since this is also a closed electrode structure layout, electromagnetic leakage is virtually eliminated, thus ensuring the quality of the pulse output waveform.

[0028] Specifically, such as Figure 1As shown, the three-coaxial Blumein pulse forming line includes: an inner regular polygonal conductor, an inner flat ceramic transmission line, a middle regular polygonal conductor, an outer flat ceramic transmission line, and an outer regular polygonal conductor arranged sequentially from the inside to the outside; The inner regular polygonal conductor, the inner flat ceramic transmission line, and the middle regular polygonal conductor constitute the inner transmission line of the Blumein pulse forming line; The outer regular polygonal conductor, the outer flat ceramic transmission line, and the middle regular polygonal conductor constitute the outer transmission line of the Blumein pulse forming line.

[0029] The inner and outer flat-plate ceramic transmission lines share the same geometric dimensions and material parameters. Therefore, the inner, middle, and outer regular polygonal conductors all possess the same polygonal shape, such as an equilateral triangle, square, regular pentagon, or regular hexagon, and so on. polygon, and At this time, both the inner flat ceramic transmission line and the outer flat ceramic transmission line are equipped with The group fits along the edges of each regular polygon.

[0030] In a further example, the inner flat ceramic transmission line and the outer flat ceramic transmission line are provided with the same relative permittivity, which is typically in the tens to thousands.

[0031] It should also be noted that, in order to ensure the electrical length matching of the pulse forming line and the impedance matching of the transmission line, the inner flat ceramic transmission line and the outer flat ceramic transmission line are designed to have the same length, width and thickness.

[0032] Furthermore, in further examples, the materials for the inner regular polygonal conductor, the middle regular polygonal conductor, and the outer regular polygonal conductor can also be selected as any conductor such as copper, stainless steel, or aluminum.

[0033] On the other hand, the present invention also provides an application method based on the three coaxial Blumlein pulse forming lines mentioned in the above embodiments, comprising: For the three coaxial Blumlein pulse forming lines in the above embodiments, such as Figure 2 As shown, a switch is connected at one end between the middle regular polygonal conductor and the outer regular polygonal conductor. The load is connected to the other end between the inner and outer regular polygonal conductors. This is used to construct the Blummlein pulse forming line circuit.

[0034] in: The switch S connected between the middle polygonal conductor and the outer polygonal conductor can be one, two, or so on. One, even indivual, indivual,……; A load is connected between the inner polygonal conductor and the outer polygonal conductor. It can be 1, 2, and so on up to... One, but the load needs to be ensured. Parallel value and cross section normal Output impedance of triaxial Blumlein pulse forming line with a closed-loop structure Matching , where the load It can be one resistor, or two, three, and so on. The parallel resistors can also be pulse transmission line cables that match the output impedance. At this point, the output impedance can be adjusted according to actual needs, for a positive cross-section The closed-structure triaxial Blumlein pulse forming line with a polygonal shape, due to A flat ceramic transmission line is connected in parallel to the positive Along the side length of the polygon, its impedance is The parallel value of a flat ceramic transmission line has a positive cross-section. The specific formula for the output impedance of the triaxial Blumlein pulse forming line with a closed polygonal structure is as follows:

[0035] in, The characteristic impedance of a single flat ceramic transmission line; Through the cross section The closed-structure triaxial Blumlein pulse forming line with a polygonal shape is designed to output pulse width. The formula for the output pulse width is as follows:

[0036] in, This represents the pulse width output by the Blumlein pulse forming line across the load. The unidirectional propagation delay (electrical length) of electromagnetic waves in a single Blumlein transmission line. Ultimately, it meets the needs of different pulse power applications.

[0037] It should be further specified that, in the above-mentioned application of the three coaxial Blumullein pulse forming line, the wave impedance between the outer regular polygonal conductor and the middle regular polygonal conductor needs to be designed to be 1-50Ω, and the wave impedance between the middle regular polygonal conductor and the inner regular polygonal conductor needs to be designed to be 1-50Ω.

[0038] Meanwhile, the electrical length of the Blumlein pulse forming line can be designed to be 5-500 ns, up to the point that the output pulse width of the Blumlein pulse forming line is 10-1000 ns.

[0039] At this time, as Figure 3 As shown, based on the use of the above-mentioned three coaxial Blumein pulse forming line with a closed structure of regular polygonal cross section, the Blumein pulse forming line can significantly reduce the size and weight of the pulse power system, while obtaining a high-voltage pulse output with a high-quality waveform.

[0040] In a further embodiment, three-dimensional electromagnetic simulation software was used to simulate the flat-plate Blumlein pulse forming line and the triaxial flat-plate Blumlein pulse forming line. The results show that, thanks to the triaxial closed structure, the output waveform flat-top of the triaxial Blumlein pulse forming line with a square cross-section closed structure is significantly better than that of the conventional flat-plate Blumlein pulse forming line. Figure 4 As shown.

[0041] As can be seen from the figure, due to the open electrode structure of the plate pulse Blumlein pulse forming line, a relatively serious electromagnetic leakage (radiation loss) occurs during the pulse formation process, resulting in distortion of the output pulse waveform (forming a stepped pulse top), which cannot meet the technical requirements of high-power particle accelerators for high-quality pulse tops.

[0042] In summary, compared to cable pulse forming lines of the same voltage level, the Blullein pulse forming line can significantly reduce the size and weight of the pulse power source; compared to ceramic solid-state pulse forming lines of the same voltage level, the Blullein pulse forming line can significantly improve the pulse output waveform quality.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0044] Furthermore, it should be noted that if any directional indication (such as up, down, left, right, front, back, etc.) is involved in the embodiments of the present invention, the directional indication is only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0045] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, in the embodiments of this invention, "multiple" refers to two or more. Moreover, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

Claims

1. A triaxial Blumlein pulse forming line, characterized in that, The pulse forming line is configured as a closed structure with a cross-section of a regular polygon. The pulse forming line is composed of a high dielectric constant flat ceramic transmission line and a coaxial conductor with a regular polygon cross-section, including an inner regular polygon conductor, an inner flat ceramic transmission line, a middle regular polygon conductor, an outer flat ceramic transmission line, and an outer regular polygon conductor arranged sequentially from the inside to the outside. The inner flat ceramic transmission line and the outer flat ceramic transmission line have the same geometric dimensions and material parameters. The inner regular polygonal conductor, the inner flat ceramic transmission line, and the middle regular polygonal conductor constitute the inner transmission line; The outer regular polygonal conductor, the outer flat ceramic transmission line, and the middle regular polygonal conductor constitute the outer transmission line; The inner regular polygonal conductor, the middle layer regular polygonal conductor, and the outer regular polygonal conductor are all set to be positive. polygon, and Both the inner flat ceramic transmission line and the outer flat ceramic transmission line are provided with The group fits along the edges of each regular polygon.

2. The triaxial Blumlein pulse forming line as described in claim 1, characterized in that, The inner flat ceramic transmission line and the outer flat ceramic transmission line have the same relative permittivity in their ceramic dielectrics.

3. The triaxial Blumlein pulse forming line as described in claim 1, characterized in that, The inner flat ceramic transmission line and the outer flat ceramic transmission line have the same length, width and thickness.

4. The triaxial Blumlein pulse forming line as described in claim 1, characterized in that, The inner regular polygonal conductor, the middle regular polygonal conductor, and the outer regular polygonal conductor are made of any one of copper, stainless steel, or aluminum.

5. A method for applying a triaxial Blumlein pulse forming line, characterized in that, include: For the triaxial Blumein pulse forming line described in any one of claims 1-4, a switch is connected at one end between the middle polygonal conductor and the outer polygonal conductor. The load is connected to the other end between the inner and outer regular polygonal conductors. This is used to construct the Blummlein pulse forming line circuit.

6. The application method of the three coaxial Blumein pulse forming lines as described in claim 5, characterized in that, Based on the characteristic impedance of the planar ceramic transmission line and the number of sides of the regular polygon, the wave impedance between the outer regular polygon conductor and the middle regular polygon conductor is adjusted to 1-50Ω, and the wave impedance between the middle regular polygon conductor and the inner regular polygon conductor is adjusted to 1-50Ω.

7. The application method of the three coaxial Blumein pulse forming lines as described in claim 5, characterized in that, By combining the geometric lengths of the ceramic dielectric and the flat ceramic transmission line, the electrical length of the Blummlein pulse forming line is adjusted to 5-500 ns, so that the output pulse width of the Blummlein pulse forming line is 10-1000 ns.

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