Low-jitter high-voltage transmission switch for electromagnetic pulse irradiation source

Abstract

The invention belongs to the technical field of gas switches, and relates to a low-jitter high-voltage transmission switch for an electromagnetic pulse irradiation source. Comprising a main gap structure and a pre-ionization gap structure, the pre-ionization gap structure is arranged in the middle of the main gap structure, the pre-ionization gap structure comprises a pre-ionization electrode disc, the pre-ionization electrode disc is arranged in the main gap structure in the radial direction of the main gap structure, and a tungsten needle electrode is arranged at one end of the pre-ionization electrode disc in an insulated mode. A metal electrode is arranged at the other end opposite to the tungsten needle electrode, and a pre-ionization gap with adjustable spacing is formed between the metal electrode and the tungsten needle electrode; and the main gap structure and the preionization gap structure are externally connected with a voltage division circuit. An external circuit is used for discharging to form pulse ultraviolet light to irradiate a switch gap so as to form initial electrons, a trigger disc is introduced between the double-electrode switches, and a pre-ionization gap with an adjustable interval is formed between a stainless steel needle and a tungsten needle electrode, so that the jitter of the switch is obviously reduced, and the switch has obvious advantages when being applied to a pulse source transmission switch.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas switches, and relates to a low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source. Background Art

[0002] In order to accelerate the leading edge of the output waveform of an electromagnetic pulse source and maintain stability, the core technology lies in the low-jitter technology of a steepening switch that withstands pulsed voltage. In this context, to achieve the output of a pulsed voltage with a very small leading edge (reaching the sub-nanosecond level) and a very high amplitude (reaching the MV level), higher requirements are imposed on the breakdown characteristics of the switch.

[0003] In 2006, Luo Min et al. from the China Academy of Engineering Physics designed an MV-class multi-channel repetitive frequency gas switch using a three-electrode spark switch. The switch had a working voltage of 1.15 MV, a peak current of 14.4 kA, a repetitive frequency of 100 Hz, a working range of 64.5%, and achieved multi-channel discharge. This switch adopted an electrical triggering form and was not suitable for a steepening circuit with high requirements for a compact structure.

[0004] In 2012, Li Junna from the Northwest Institute of Nuclear Technology developed a 3 MV ultraviolet pre-ionization switch with a working voltage range of 1.6 - 2.5 MV. Under a leading-edge pulse waveform of 300 ns, the breakdown voltage dispersion was less than 25 kV, and the breakdown jitter was 5 ns. This switch adopted a resistive pre-ionization scheme, inserted a highly inhomogeneous field in the main gap electric field of the switch, had a relatively high voltage level, and had small dispersion and jitter. However, this switch consisted of three-stage spark gaps connected in series, and the inductance of the switch structure was relatively large, making it difficult to meet the low-inductance requirements of the output circuit.

[0005] In 2020, Guo Fan et al. from the Northwest Institute of Nuclear Technology developed an MV-class sulfur hexafluoride pre-ionization switch with a maximum working voltage of 1 MV. When the switch gap was 5 mm, the self-breakdown jitter was 0.37 - 1.69 ns. By means of a capacitive pre-ionization structure and adjusting the switch test state to meet the conditions of field emission and gas pressure threshold, the breakdown delay and jitter of the gas switch under nanosecond pulses were significantly reduced, providing a reference for reducing the inductance of the switch structure.

[0006] Regarding the working characteristics of the pre-ionization switch, Li Junna's research showed that its time jitter was positively correlated with the pulsed voltage jitter it withstood, and the conclusion was approximately 1% of the pulse leading edge; Wang Tianchi deduced and verified the breakdown probability distribution of a multi-stage series switch through the fact that the breakdown probability of a single-stage pulsed switch follows the Weibull distribution, and proposed that the pre-ionization injection time was the key factor affecting the switch delay jitter. By increasing the pre-ionization gap voltage and adopting the method of continuous pre-ionization, the switch jitter under a 240 ns leading-edge pulse was reduced to 1.3 ns.

[0007] As one of the key components of a pulse source, the working characteristics of a gas switch directly affect the output of the pulse source. The sub-nanosecond front edge and megavolt-level high voltage pose higher requirements for the breakdown voltage and breakdown delay of the gas switch. However, in the research of existing technologies, the jitter of high-voltage transfer switches remains relatively high. Summary of the Invention

[0008] The purpose of the present invention is to provide a low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source to solve the technical problem of high jitter of high-voltage transfer switches in existing electromagnetic pulse irradiation sources.

[0009] To achieve the above object, the present invention adopts the following technical solutions: The present application discloses a low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source, including a main gap structure and a pre-ionization gap structure. The pre-ionization gap structure is arranged in the middle of the main gap structure. The pre-ionization gap structure includes a pre-ionization electrode disk, which is arranged radially in the main gap structure along the radial direction of the main gap structure. One end of the pre-ionization electrode disk is insulated with a tungsten needle electrode, and the other end is provided with a metal electrode opposite to the tungsten needle electrode. An adjustable-spacing pre-ionization gap is formed between the metal electrode and the tungsten needle electrode; and the main gap structure and the pre-ionization gap structure are externally connected to a voltage-dividing circuit.

[0010] Preferably, the tungsten needle electrode includes a pre-ionization voltage-dividing electrode head, which is insulated on the pre-ionization electrode disk. A through hole is opened inside the pre-ionization voltage-dividing electrode head, and a tungsten needle is fixed at the through hole by a flat-end bolt. The tungsten needle is integrally embedded in a ceramic sleeve and extends deep into the pre-ionization electrode disk, and is arranged opposite to the metal electrode.

[0011] Preferably, the pre-ionization voltage-dividing electrode head is arranged on the pre-ionization electrode disk through a nylon adapter.

[0012] Preferably, the metal electrode includes a stainless-steel needle and a pre-ionization voltage-dividing electrode head. The pre-ionization voltage-dividing electrode head is fixed on the pre-ionization electrode disk, and the stainless-steel needle is fixed on the pre-ionization voltage-dividing electrode head and arranged opposite to the tungsten needle electrode.

[0013] Preferably, the main gap structure includes two electrode disks, which are arranged opposite to each other. The pre-ionization gap structure is arranged between the two electrode disks. The electrode disks and the pre-ionization gap structure are connected by an organic glass cylinder, and a hemispherical main electrode is fixedly connected to the electrode disks.

[0014] Preferably, the electrode disks and the organic glass cylinder are tightened and fixed by nylon bolts; and on the electrode disks, grooves are opened at the positions in contact with the organic glass cylinder, and arc grooves are arranged on the inner and outer walls of the organic glass cylinder.

[0015] Preferably, the hemispherical head main electrode is fixedly connected to the electrode disk through screws at both ends, and a hollow cylinder is arranged between the hemispherical head main electrode and the electrode disk outside the screws at both ends.

[0016] Preferably, the pre-ionization gap structure and the plexiglass cylinder are tightened and fixed through nylon bolts.

[0017] Preferably, N2 is used as the insulating medium inside the switch, and the working air pressure is 1-8 atm.

[0018] Preferably, the voltage dividing circuit is as follows: a resistor is arranged between one electrode disk and the tungsten needle electrode, and a resistor is arranged between the other electrode disk and the metal electrode to form a parallel resistor of the inner electrodes of the main gap structure; a resistor is arranged between the tungsten needle electrode and the metal electrode to form a parallel resistor of the inner electrodes of the pre-ionization gap structure; and the voltage division ratio of the parallel resistor of the inner electrodes of the main gap structure to the parallel resistor of the inner electrodes of the pre-ionization gap structure is 33:1.

[0019] Compared with the prior art, the present invention has the following beneficial effects: A low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source disclosed in the present application uses an external circuit discharge to form pulsed ultraviolet light to irradiate the switch gap to form initial electrons, introduces a trigger disk between the double-electrode switch, and forms an adjustable-spacing pre-ionization gap between the stainless steel needle and the tungsten needle electrode to ensure that the pre-ionization electrode disk is exactly in the middle of the two main electrodes; through the breakdown characteristic test, it is measured that under the pulsed voltage with a leading edge of about 100 ns of the pre-ionization switch, the breakdown voltage jitter of the main switch is reduced from 8.8% - 12.6% to 3.5% - 8.6%, and the breakdown delay jitter is reduced from 20.7% - 23.2% to 14.2% - 16.7%. Compared with the existing switch, the jitter of this switch is significantly reduced, and it has obvious advantages when applied to the pulse source transfer switch. Moreover, the pre-ionization gap of the present application is for low delay and low jitter, and the adjustable gap is to enable the switch to work in the range of 300 kv to 1 mv by adjusting the gap and air pressure while keeping the main gap of the switch unchanged.

[0020] In some embodiments, the tungsten needle is integrally embedded in the ceramic sleeve and extends deep into the pre-ionization electrode disk, and is arranged opposite to the stainless steel needle. The ceramic sleeve ensures the insulation between the electrode disk and at the same time stabilizes the coaxial structure of the tungsten needle and the stainless steel needle on the opposite side, promoting higher utilization rates of ultraviolet light and channel electrons by the pre-ionization gap, and ensuring the effectiveness of the switch action. Description of the Drawings

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can be obtained based on these drawings.

[0022] Figure 1 Cross-sectional schematic diagram of the low-jitter high-voltage transfer switch according to the embodiment of the present invention; Figure 2 Cross-sectional schematic diagram of the pre-ionization electrode disk structure according to the embodiment of the present invention; Figure 3 Schematic diagram of the tungsten needle structure in the cross-section of the pre-ionization electrode disk structure according to the embodiment of the present invention.

[0023] Wherein: 1 - electrode disk; 2 - plexiglass cylinder; 3 - hemispherical head main electrode; 4 - hollow cylinder; 5 - both-end screw; 6 - pre-ionization electrode disk; 7 - nylon bolt; 8 - pre-ionization gap; 9 - tungsten needle; 10 - nylon adapter; 11 - ceramic bushing; 12 - M2 flat-end bolt. Detailed implementation manners

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0026] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0027] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is usually placed during use. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0028] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0029] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "connected" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0030] The following further describes the present invention in detail with reference to the drawings: See Figure 1 , this application discloses a low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source, including a main gap structure and a pre-ionization gap structure. The pre-ionization gap structure is arranged in the middle of the main gap structure. The pre-ionization gap structure includes a pre-ionization electrode disk 6. The pre-ionization electrode disk 6 is arranged radially in the main gap structure along the radial direction of the main gap structure. One end of the pre-ionization electrode disk 6 is insulated with a tungsten needle electrode, and the other end is provided with a metal electrode opposite to the tungsten needle electrode. An adjustable-spacing pre-ionization gap is formed between the metal electrode and the tungsten needle electrode; and the main gap structure and the pre-ionization gap structure are externally connected to a voltage-dividing circuit The pre-ionization technology is adopted to reduce the breakdown jitter of the switch. Its essence is to provide initial electrons for the gap at the initial stage of gas discharge development or enhance the photoionization effect, so as to reduce the statistical delay or the jitter of the formation delay, thereby achieving the purpose of reducing the breakdown jitter of the switch. The specific methods include: one is to irradiate the switch gap with an ultraviolet lamp, and the ultraviolet rays directly ionize or stepwise ionize gas molecules to generate stable initial electrons; the other is to use the discharge of the external circuit to form pulsed ultraviolet light or directly inject high-energy rays to irradiate the switch gap to form initial electrons. When irradiating the switch gap with an ultraviolet lamp, due to the continuous and stable electrons in the gas, when the switch gap has not reached or is far lower than the self-breakdown voltage, the development of the gap discharge is already very sufficient, resulting in too low a breakdown voltage. Therefore, it is often used as a research means and is not widely applied in pulsed power devices. When using the discharge of the external circuit to form ultraviolet pre-ionization, the present application simplifies the external circuit and the introduction method of high-voltage isolation, avoids the influence of the external circuit on the main circuit discharge, and avoids giving up the use due to the system being too complex and losing the advantages of the pre-ionization technology.

[0031] In some embodiments, the tungsten needle electrode includes a pre-ionization voltage-dividing electrode head 13, and the pre-ionization voltage-dividing electrode head 13 is insulated and arranged on the pre-ionization electrode disc 6. A through hole is opened inside the pre-ionization voltage-dividing electrode head 13, and a tungsten needle 9 is fixed at the through hole by a flat-end bolt 12. The tungsten needle 9 is integrally embedded in the ceramic sleeve 11 and extends into the pre-ionization electrode disc 6, and is arranged opposite to the metal electrode.

[0032] In some embodiments, the pre-ionization voltage-dividing electrode head 13 is arranged on the pre-ionization electrode disc 6 through a nylon adapter 10.

[0033] In some embodiments, the metal electrode includes a stainless steel needle and a pre-ionization voltage-dividing electrode head 13. The pre-ionization voltage-dividing electrode head 13 is fixed on the pre-ionization electrode disc 6, and the stainless steel needle is fixed on the pre-ionization voltage-dividing electrode head 13 and is arranged opposite to the tungsten needle electrode.

[0034] In some embodiments, the main gap structure includes two electrode discs 1, the two electrode discs 1 are arranged opposite to each other, the pre-ionization gap structure is arranged between the two electrode discs 1, the electrode discs 1 and the pre-ionization gap structure are connected by an acrylic cylinder 2, and a hemispherical head main electrode 3 is fixedly connected to the electrode discs 1.

[0035] In some embodiments, the electrode disc 1 and the acrylic cylinder 2 are tightened and fixed by nylon bolts 7; and on the electrode disc 1, a groove is opened at the position where it contacts the acrylic cylinder 2, and arc grooves are provided on the inner and outer walls of the acrylic cylinder 2.

[0036] In some embodiments, the hemispherical head main electrode 3 is fixedly connected to the electrode disc 1 through two-end screws 5, and a hollow cylinder 4 is arranged between the hemispherical head main electrode 3 and the electrode disc 1 on the outside of the two-end screws 5.

[0037] In some embodiments, the pre-ionization gap structure and the plexiglass cylinder 2 are tightly fixed by nylon bolts 7.

[0038] In some embodiments, N2 is used as the insulating medium inside the switch, and the operating air pressure is 1 - 8 atm.

[0039] In some embodiments, the voltage-dividing circuit is as follows: a resistor is arranged between one electrode disk 1 and the tungsten needle electrode, and a resistor is arranged between the other electrode disk 1 and the metal electrode to form a parallel resistor of the inner electrodes of the main gap structure; a resistor is arranged between the tungsten needle electrode and the metal electrode to form a parallel resistor of the inner electrodes of the pre-ionization gap structure; and the voltage division ratio of the parallel resistor of the inner electrodes of the main gap structure to the parallel resistor of the inner electrodes of the pre-ionization gap structure is 33:1.

[0040] In some embodiments, the transfer switch is designed as a resistance voltage-dividing type with a voltage division ratio of 33:1. The main gap adopts a slightly non-uniform field structure, and the pre-ionization gap adopts an extremely non-uniform field structure. N2 is used as the insulating medium inside the switch, and the operating air pressure is designed to be 1 - 8 atm. Pure SF6 gas is used as the insulating medium outside the switch, and the operating air pressure is 3 atm.

[0041] In some embodiments, the transfer switch adopts a single-stage self-breaking switch, including the main gap of the switch and the ultraviolet pre-ionization gap, and its cross-sectional view is as Figure 1 shown. The radius of the electrode disk is 120 mm. The switch housing consists of two identical plexiglass cylinders 2. The electrode disk 1 and the plexiglass cylinder 2 are tightly fixed by nylon bolts 7. The main electrode adopts a hemispherical head shape, the material is selected as brass, the outer radius of the electrode is 40 mm, and the electrode spacing is 60 mm. To ensure the creepage insulation distance of the switch housing, the electrodes at both ends need to be lengthened. To reduce the weight, the middle part of the electrode is hollowed out, and the electrode disk and the ball head electrode are connected by two end screws in the middle. The ball head is fixed by a hollow cylinder outside to reduce the stress on the screw to ensure the electrode spacing.

[0042] In some embodiments, the switch housing uses plexiglass as the support insulator. When simulating the electric field of the double-electrode switch, it can be found that in addition to the electrode surface, a relatively high electric field strength appears at the contact point between the electrode disk and the plexiglass housing. This is because this contact point is a triple junction of "electrode - gas - dielectric", which will cause electric field distortion. Therefore, a groove is designed on the electrode disk to embed the plexiglass cylinder, thereby forming a stepped structure to shield the electric field strength at the triple junction and further reduce the creepage electric field on the plexiglass. The inner and outer surfaces of the plexiglass cylinder are processed with arc grooves, which not only increases the creepage distance, but also makes the electric field around the wall of the plexiglass cylinder uniform, reducing the creepage electric field.

[0043] In some embodiments, the cross-sectional view of the pre-ionization electrode disk of the transfer switch is as Figure 2 、Figure 3 As shown, one end electrode is a tungsten needle 9 with a diameter of 1.6 mm and a length of 150 mm. The whole tungsten needle 9 is embedded in a ceramic sleeve 11 with an inner diameter of 2 mm, an outer diameter of 4 mm, and a length of 140 mm to ensure insulation from the electrode disk, and at the same time, it stabilizes the coaxial structure with the opposite electrode. The metal electrode is 304 stainless steel, with an internal opening to fix the tungsten needle through an M2 flat-end bolt 12. A nylon adapter is designed between the electrode head and the electrode disk to ensure insulation. The other end electrode is a 304 stainless steel needle that is fastened to the electrode disk by threads and can adjust the pre-ionization gap spacing.

[0044] Embodiment Use COMSOL to perform electrostatic field simulation on the main gap and pre-ionization gap of the transfer switch. The distance of the main switch gap is 60 mm, and the distance of the pre-ionization gap is 10 mm. Assuming that the operating voltage of the switch is 1.28 MV under ideal conditions, the pre-ionization gap voltage is about 38 kV.

[0045] It can be seen from the simulation results that the maximum value of the electric field in the main gap of the transfer switch is at the very front end of the spherical head electrode, which is 305 kV / cm. The average electric field of the main gap is 213.3 kV / cm, and the electric field non-uniformity coefficient of the main gap is 1.43. The electric field is a slightly non-uniform field; the maximum value of the electric field in the pre-ionization gap is 257 kV / cm, the average electric field is 38 kV / cm, and the electric field non-uniformity coefficient is 6.76, which is an extremely non-uniform field. All meet the design requirements.

[0046] The discharge time delay of the breakdown of the gas switch can be divided into statistical time delay and discharge time delay. The jitter of its discharge time delay determines the jitter of the breakdown of the gas switch. The transfer switch adopts a resistive voltage division type ultraviolet pre-ionization structure. The pre-ionization gap breaks down first, causing the electric field inside the switch to distort, reducing the discharge time delay of the breakdown of the main switch gap, and reducing the working jitter of the steepening circuit in the pulse source. Therefore, it is necessary to determine the breakdown moment of the pre-ionization gap of the transfer switch, and adjust the breakdown moment of the pre-ionization gap by the distance of the pre-ionization electrode gap, so as to cooperate with the breakdown moment of the main switch gap to achieve the purpose of reducing the breakdown jitter of the transfer switch.

[0047] For the designed transfer switch, design experiments to explore its pre-ionization working characteristics. Build an LC series discharge circuit through a pneumatic trigger switch to output a waveform with an adjustable voltage amplitude and a front edge of about 100 ns. Then, generate a waveform similar to the actual applied voltage at both poles of the transfer switch through a water resistance voltage division. Measure the voltage of the ground electrode of the transfer switch and the voltage of the pre-ionization electrode disk through a voltage divider, and study and analyze their breakdown characteristics respectively.

[0048] According to the experimental results, a low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source disclosed in the present application can significantly reduce the jitter of the breakdown voltage and delay of the main switch. However, at the same time, an inevitable reduction in the breakdown voltage will occur. It is analyzed that at this time, since the pre-ionization switch breaks down first, while ionizing the gas medium between the main switches and causing electric field distortion, it provides the initial electrons for the breakdown of the main switch, thus reducing the breakdown voltage of the main switch. Under the working conditions of nitrogen at 1 - 3 atm, the pre-ionization switch reduces the breakdown voltage jitter of the main switch from 8.8% - 12.6% to 3.5% - 8.6%, and reduces its breakdown delay jitter from 20.7% - 23.2% to 14.2% - 16.7%. This can prove that for a front-edge pulse voltage of about 100 ns, the introduction of the pre-ionization gap can reduce the breakdown jitter of the main switch and improve the synchronization of the second-stage steepening unit. The designed resistor voltage-dividing ultraviolet pre-ionization self-breakdown switch can be applied to the transfer switch.

[0049] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source, characterized in that It includes a main gap structure and a pre-ionization gap structure. The pre-ionization gap structure is arranged in the middle of the main gap structure. The pre-ionization gap structure includes a pre-ionization electrode disc (6). The pre-ionization electrode disc (6) is arranged radially in the main gap structure. One end of the pre-ionization electrode disc (6) is insulated with a tungsten needle electrode, and the other end is provided with a metal electrode opposite to the tungsten needle electrode. An adjustable-spacing pre-ionization gap is formed between the metal electrode and the tungsten needle electrode; and the main gap structure and the pre-ionization gap structure are externally connected to a voltage-dividing circuit.

2. The low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source according to claim 1, wherein The tungsten needle electrode includes a pre-ionization voltage-dividing electrode head (13). The pre-ionization voltage-dividing electrode head (13) is insulated and arranged on the pre-ionization electrode disc (6). A through hole is opened inside the pre-ionization voltage-dividing electrode head (13). A tungsten needle (9) is fixed at this through hole by a flat-end bolt (12). The tungsten needle (9) is integrally embedded in a ceramic sleeve (11) and extends into the pre-ionization electrode disc (6), and is arranged opposite to the metal electrode.

3. The low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source according to claim 2, characterized in that, The pre-ionization voltage-dividing electrode head (13) is arranged on the pre-ionization electrode disc (6) through a nylon adapter (10).

4. A low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source according to claim 1, characterized in that, The metal electrode includes a stainless steel needle and a pre-ionization voltage-dividing electrode head (13). The pre-ionization voltage-dividing electrode head (13) is fixed on the pre-ionization electrode disc (6). The stainless steel needle is fixed on the pre-ionization voltage-dividing electrode head (13) and is arranged opposite to the tungsten needle electrode.

5. The low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source according to claim 1, wherein The main gap structure includes two electrode discs (1). The two electrode discs (1) are arranged opposite to each other. The pre-ionization gap structure is arranged between the two electrode discs (1). The electrode discs (1) and the pre-ionization gap structure are connected by an organic glass cylinder (2). A hemispherical head main electrode (3) is fixedly connected to the electrode disc (1).

6. The low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source according to claim 5, characterized in that, The electrode disc (1) and the organic glass cylinder (2) are tightened and fixed by a nylon bolt (7); and on the electrode disc (1), a groove is opened at the position where it contacts the organic glass cylinder (2). Arc grooves are provided on the inner and outer walls of the organic glass cylinder (2).

7. A low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source according to claim 5, characterized in that, The hemispherical head main electrode (3) is fixedly connected to the electrode disc (1) by two end screws (5). And outside the two end screws (5), a hollow cylinder (4) is arranged between the hemispherical head main electrode (3) and the electrode disc (1).

8. A low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source according to claim 5, characterized in that The pre-ionization gap structure and the organic glass cylinder (2) are tightened and fixed by a nylon bolt (7).

9. The low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source according to claim 1, characterized in that, The inside of the switch uses N2 as the insulating medium, and the working air pressure is 1 - 8 atm.

10. A low-jitter high-voltage transfer switch for an electromagnetic pulse irradiation source according to claim 5, characterized in that, The voltage-dividing circuit is as follows: A resistor is arranged between one electrode disc (1) and the tungsten needle electrode, and a resistor is arranged between the other electrode disc (1) and the metal electrode to form a parallel resistor of the electrodes in the main gap structure; the resistor between the tungsten needle electrode and the metal electrode forms a parallel resistor of the electrodes in the pre-ionization gap structure; and the voltage division ratio of the parallel resistor of the electrodes in the main gap structure to the parallel resistor of the electrodes in the pre-ionization gap structure is 33∶1.

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