A method for evaluating breakdown delay and jitter performance of gas switches

Abstract

The present invention discloses a method for evaluating the breakdown delay and jitter performance of gas switches, relating to the technical field of gas switches. By searching for data on the melting point, density, specific heat capacity, and work function of electrode materials and calculating changes in the work function of binary alloy materials, the method can directly evaluate the breakdown delay and jitter performance of different electrode materials. Compared with previous methods that required extensive experimental comparisons of the breakdown delay and jitter performance of gas switches made of different electrode materials, this method can significantly reduce work time and workload, thereby improving experimental efficiency and reducing experimental costs.

Description

Technical Field

[0001] The present invention relates to the technical field of gas switches, and more particularly to a method for evaluating breakdown delay and jitter performance of a gas switch. Background Art

[0002] Gas spark switches are key components for achieving electrical power amplification in pulse devices. They have the advantages of simple structure, reliable performance, and easy installation, and are widely used in primary pulse sources. Fast pulse linear transformer drivers (FLTDs) typically control the operation of hundreds of thousands of gas switches. Accurate and reliable triggering control of these numerous gas switches is a major engineering challenge. Structural characteristics require higher reliability for gas switches, meaning they must have lower jitter (standard deviation of breakdown delay). Electrode material is one of the key factors affecting the breakdown delay and jitter of gas spark switches. For the same gas switch, the current method is mainly to compare the effects of different electrode materials on the breakdown delay and jitter performance of the switch through experiments. Jitter is the standard deviation of the breakdown delay, and obtaining results requires significant time and cost.

[0003] Therefore, it is a difficult problem to obtain the switch breakdown delay and jitter performance of different electrode materials through theoretical calculation. Summary of the Invention

[0004] In view of this, the present invention provides a method for evaluating the breakdown delay and jitter performance of a gas switch based on electrode materials, so as to solve the problems of low efficiency and high experimental cost of the existing breakdown delay and jitter experiments of gas switches.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for evaluating the breakdown delay and jitter performance of a gas switch comprises the following steps:

[0007] Step 1: Determine the physical parameters of the metal electrode material of the gas switch to be evaluated; obtain the work function of the metal electrode material to be evaluated Density ρ, specific heat c, melting point T;

[0008] Step 2: Calculate the average work function of metal atoms that generate field emission on the surface of the electrode material The calculation formula is as follows:

[0009]

[0010] are the work functions of different atoms in the electrode materials, and A and B are their proportions in the electrode materials;

[0011] Step 3: Calculate the variance of the cubic square of the atomic work function caused by field electron emission by the electrode material The calculation formula is as follows:

[0012]

[0013] Step 4: Use numerical calculation software to calculate the expected inverse of the surface field enhancement factor of the electrode material after N discharges and variance The calculation formula is as follows:

[0014]

[0015] R z is the height of the surface protrusion, r is the radius of the surface protrusion; n is the number of discharges at the protrusion position, Z m is the melting depth, ρ is the density, c is the specific heat capacity, T is the melting point, and q is the total heat input to the electrode surface in a single discharge;

[0016] Step 5: Calculate the breakdown delay characteristic parameter K1 of the gas switch of different electrode materials;

[0017]

[0018] Among them, the larger the gas switch breakdown delay characteristic parameter K1 is, the longer the switch breakdown delay is.

[0019] Step 6: Calculate the jitter index K2 of gas switches with different electrode materials. The calculation formula is as follows:

[0020]

[0021] Among them, the smaller the evaluation index K2 is, the better the jitter performance of the material is.

[0022] Preferably, the metal electrode material to be evaluated is a single metal or a multi-element alloy.

[0023] Preferably, in step 1, the work function of the metal electrode material to be evaluated is obtained by searching for data or performing instrument testing. Density ρ, specific heat c, melting point T.

[0024] Preferably, the surface protrusion radius in step 4 is measured by a surface profilometer.

[0025] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. By searching for data on the melting point, density, specific heat capacity, and work function of electrode materials and calculating changes in the work function of binary alloy materials, the method of the present invention can directly evaluate the breakdown delay and jitter performance of different electrode materials. Compared with previous methods that required extensive experimental comparisons of the breakdown delay and jitter performance of gas switches made of different electrode materials, this method can significantly reduce work time and workload, thereby improving experimental efficiency and reducing experimental costs.

[0027] 2. When the method of the present invention is used to evaluate the breakdown delay and jitter performance of gas switches with different electrode materials, the evaluation results are consistent with the experimental results in most literatures. The evaluation results are basically consistent with the experimental results, indicating that the method of the present invention for evaluating the breakdown delay and jitter performance of gas spark switches is accurate and effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0029] Figure 1 This is a calculation flow chart of the method for evaluating the breakdown delay and jitter performance of the gas spark switch of the present invention.

[0030] Figure 2 This is the schematic diagram of the gas spark switch experimental circuit;

[0031] Figure 3 This is the structural diagram of the gas spark switch. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] Example 1

[0034] The jitter performance of gas switches made of W70 / Cu alloy, stainless steel, and brass was evaluated using the method of the present invention. The evaluation results were compared with the experimental results. The specific jitter performance and energy evaluation steps are as follows:

[0035] Step 1: Find the melting point T, density ρ, specific heat capacity c and work function of the above electrode materials in the literature and related material manuals The search results are shown in Table 1 below:

[0036] Table 1

[0037]

[0038] Step 2: Calculate the average work function of metal atoms that undergo field emission on the surface of the electrode material The calculation formula is as follows, are the work functions of different atoms in the electrode materials, and A and B are their proportions in the electrode materials.

[0039]

[0040] The calculation results are shown in the following table:

[0041] Table 2

[0042]

[0043] Step 3: Calculate the variance of the cubic square of the atomic work function caused by field electron emission by the electrode material The calculation formula is as follows:

[0044]

[0045] The calculation results are shown in the following table:

[0046] Table 3

[0047]

[0048] Step 4: Use numerical calculation software to calculate the expected inverse of the surface field enhancement factor of the electrode material after 1000 discharges and variance The calculation formula is as follows, R z is the average height of the effective protrusions on the surface, which is 100 μm, and the number is 100. r is the radius of the surface protrusion tip, which is 0.5 μm. n is the number of discharges at the protrusion position, and Z m is the melting depth, in cm; ρ is the density, c is the specific heat capacity, T is the melting point, and q is the heat input to the electrode surface in a single discharge, which is 10 J / cm 2 .

[0049]

[0050]

[0051] The calculation results are shown in the following table:

[0052] Table 4

[0053]

[0054] Step 5: Calculate the breakdown delay characteristic parameter K1 of the gas switch for different electrode materials

[0055]

[0056] Substituting the data into the formula, the breakdown delay evaluation indicators of W70 / Cu, stainless steel, H62 brass, Fe, and Cu are calculated to be: 4.58×10 -2 , 4.508×10 -2 , 4.5316×10 -2 That is, using the method of the present invention, the average breakdown delay time of these three electrode materials is ranked from long to short as W70 / Cu, H62 brass, and stainless steel.

[0057] Step 6: Calculate the jitter index K2 of gas switches with different electrode materials. The calculation formula is as follows;

[0058]

[0059] Substituting the data into the formula, the breakdown jitter parameters of W70 / Cu, stainless steel, and H62 brass are calculated to be: 9.9×10 -3 , 1.2×10 -2 , 7.85×10 -2 That is, the gas switch jitter rankings of the three electrode materials using the method of the present invention are as follows: H62 brass, stainless steel, and W70 / Cu.

[0060] At the same time, the present invention uses W70 / Cu alloy, stainless steel, and brass to conduct 50 discharge experiments respectively to measure their breakdown delays and calculate their jitters.

[0061] The schematic diagram of the switch experimental circuit is as follows Figure 2 As shown, a two-gap gas switch and two capacitors form a short-circuit discharge loop. The positive and negative high-voltage power supplies charge the two capacitors respectively through 500kΩ charging resistors. The fast-leading trigger outputs a 15ns negative-polarity trigger pulse and applies it to the switch trigger electrode.

[0062] Switch structure such as Figure 3 As shown, the distance between the trigger electrode and the upper and lower electrodes is 5 mm, and the upper and lower electrodes and the trigger electrode are all ring-shaped, with inner and outer diameters of 20 mm and 50 mm respectively;

[0063] The charging voltage was ±25kV, the trigger voltage was -45kV, and the air pressure was set to 0.15MPa. The switch was aged 500 times before the experiment. Each time the switch broke down, the switch cavity was ventilated through the air circuit control system. The starting point of the trigger electrode voltage and the starting point of the loop current were used as the breakdown delay of the switch.

[0064] The experimental results are shown in Table 5 below

[0065] Table 5

[0066]

[0067] As shown in Table 5, the average breakdown delay of these three electrode materials, ranked from longest to shortest, is W70 / Cu, H62 brass, and stainless steel; and the jitter ranking, ranked from greatest to least, is H62 brass, stainless steel, and W70 / Cu. This is consistent with the results of the evaluation method presented in this paper, demonstrating its complete accuracy and effectiveness.

[0068] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0069] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for evaluating the breakdown delay and jitter performance of a gas switch, characterized in that: The following steps are involved: Step 1: Determine the physical parameters of the metal electrode material of the gas switch to be evaluated; Obtain the work function of the metal electrode material to be evaluated Density ρ, specific heat c, melting point T; Step 2: Calculate the average work function of metal atoms that generate field emission on the surface of the electrode material The calculation formula is as follows: are the work functions of different atoms in the electrode materials, and A and B are their proportions in the electrode materials; Step 3: Calculate the variance of the cubic square of the atomic work function caused by field electron emission by the electrode material The calculation formula is as follows: Step 4: Use numerical calculation software to calculate the expected inverse of the surface field enhancement factor of the electrode material after N discharges and variance The calculation formula is as follows: R z is the height of the surface protrusion, r is the radius of the surface protrusion; n is the number of discharges at the protrusion position, Z m is the melting depth, ρ is the density, c is the specific heat capacity, T is the melting point, and q is the total heat input to the electrode surface in a single discharge; Step 5: Calculate the breakdown delay characteristic parameter K1 of the gas switch of different electrode materials; Step 6: Calculate the jitter index K2 of gas switches with different electrode materials. The calculation formula is as follows:

2. A method for evaluating breakdown delay and jitter performance of a gas switch according to claim 1, characterized in that: The metal electrode material to be evaluated is a single metal or a multi-element alloy.

3. A method for evaluating breakdown delay and jitter performance of a gas switch according to claim 2, characterized in that: In step 1, the work function of the metal electrode material to be evaluated is obtained by searching for information or performing instrument testing. Density ρ, specific heat c, melting point T.

4. A method for evaluating breakdown delay and jitter performance of a gas switch according to claim 3, characterized in that: The surface protrusion radius in step 4 is measured by a surface profilometer.

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