Plasma local heat balance evaluation method, system, equipment and medium
By performing power exponential fitting of plasma characteristic atomic spectra, the local thermal equilibrium state of the plasma is directly evaluated, which solves the complex and time-consuming problems in the prior art, and achieves a fast and reliable local thermal equilibrium evaluation.
Patent Information
- Application Number
- CN202411805298.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-05-30
AI Technical Summary
When evaluating the local thermal equilibrium state of plasma, the prior art relies on complex equipment and cumbersome processes, which are costly, long time and have high technical requirements for operators, and lacks simple, fast and reliable evaluation methods.
By obtaining multiple characteristic atomic spectra of the same element of the plasma, including spectral intensity and upper energy level energy, power exponential fitting is performed to directly evaluate the local thermal equilibrium state of the plasma.
The local thermal equilibrium evaluation process is simplified, the cost and time requirements are reduced, the speed and reliability of the evaluation are improved, and the degree to which the plasma deviates from the local thermal equilibrium is simplified.
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Figure CN120064149A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of plasma, and in particular to a method for evaluating local thermal equilibrium of plasma. Background Art
[0002] Plasma is an ionized gas composed of charged particles, which is widely used in industrial manufacturing (such as plasma cutting and coating), medical treatment (such as plasma disinfection), and scientific research (such as astrophysics and nuclear fusion). The properties and behaviors of plasma have an important impact on its application effects. Therefore, studying the state and characteristics of plasma is an important link in plasma applications.
[0003] In the study of plasma, local thermodynamic equilibrium (LTE) is an important concept. When the plasma is in a local thermal equilibrium state, the velocity distribution, energy level distribution, and ionization degree of particles can all be described by a common temperature, which greatly simplifies the description and calculation of plasma. However, in practical applications, the plasma often deviates from the local thermal equilibrium state, resulting in more complex properties. Therefore, evaluating whether the plasma is in a local thermal equilibrium state is of great significance for understanding and controlling plasma behavior.
[0004] Traditional methods for evaluating local thermal equilibrium of plasma mainly rely on complex equipment and cumbersome processes. For example, it is usually necessary to measure the electron temperature and electron density of the plasma and judge the state of the plasma through complex numerical simulations. These methods not only require high-cost experimental equipment and long experimental times, but also have high requirements for the technical level of operators. Therefore, it has become an urgent problem to propose a simple, fast, and reliable method for evaluating local thermal equilibrium of plasma. Summary of the Invention
[0005] The purpose of the present invention is to provide a method, system, device, and medium for evaluating local thermal equilibrium of plasma that simplifies the evaluation process of local thermal equilibrium.
[0006] The purpose of the present invention can be achieved by the following technical solutions:
[0007] A method for evaluating local thermal equilibrium of plasma, comprising the following steps:
[0008] Obtain multiple characteristic atomic spectra of the same element of the plasma, where the characteristic atomic spectra include spectral intensity and upper energy level energy;
[0009] Based on the spectral intensity and upper energy level energy, perform power exponent fitting to obtain a power exponent;
[0010] Evaluate the local thermal equilibrium state of the plasma according to the power exponent.
[0011] Further, the step of performing power exponent fitting includes:
[0012] Substitute the spectral intensity into Equation (1):
[0013]
[0014] According to Equation (1) and E n Perform power exponent fitting to obtain the power exponent fitting form:
[0015]
[0016] In the formula: I nm is the spectral intensity of the transition energy levels n and m, λ nm is the wavelength of the transition energy levels n and m, A nm is the transition probability of the energy levels n and m, g n is the degeneracy of the upper energy level n, z is the charge state, E n is the energy of the upper energy level n, k is the Boltzmann constant, T is the temperature, v is the power exponent, Γ is the gamma function, h is the Planck constant, c is the speed of light in vacuum, N is the particle number density, U(T) is the partition function. In the fitting, A and C can be regarded as constants.
[0017] Further, the energy difference between the upper energy levels of the characteristic atomic spectra is greater than 0.5 eV.
[0018] Further, the number of the characteristic atomic spectra is more than 3.
[0019] Further, the evaluation of the local thermal equilibrium state of the plasma includes the following:
[0020] Judge whether the power exponent is equal to 1 or greater than 1. If it is equal to 1, it is determined that the plasma satisfies the local thermal equilibrium state. If it is greater than 1, it is determined that the plasma does not satisfy the local thermal equilibrium state.
[0021] Further, the elemental species of the plasma include hydrogen H, helium He, nitrogen N, oxygen O, argon Ar, krypton Kr, xenon Xe, neon Ne, radon Rn, metal elements, and halogen elements.
[0022] Further, the spectral intensity is the integral of the spectral line intensity.
[0023] The present invention also provides a plasma local thermal equilibrium evaluation system, including:
[0024] Spectrum acquisition module: used to acquire multiple characteristic atomic spectra of the same element of the plasma, and the characteristic atomic spectra include spectral intensity and upper energy level;
[0025] Fitting module: configured to perform calculations and power exponential fitting respectively based on the spectral intensity and upper energy level, so as to obtain a power exponent.
[0026] Evaluation module: configured to evaluate the local thermal equilibrium state of the plasma according to the power exponent.
[0027] The present invention also provides an electronic device, including: one or more processors; a memory; and one or more programs stored in the memory, where the one or more programs include instructions for executing the plasma local thermal equilibrium evaluation method as described above.
[0028] The present invention also provides a computer-readable storage medium, including one or more programs for execution by one or more processors of an electronic device, where the one or more programs include instructions for executing the plasma local thermal equilibrium evaluation method as described above.
[0029] Compared with the prior art, the present invention has the following beneficial effects:
[0030] (1) According to the spectral intensity and upper energy level in the characteristic atomic spectrum of the same element of the plasma, the present invention performs power exponential fitting calculations, and directly reflects the local thermal equilibrium state of the plasma through the value of the power exponent. The present invention does not need to calculate the electron temperature, electron density, etc. of the plasma, and can directly evaluate the local thermal equilibrium state according to the characteristic atomic spectrum, simplifying the local thermal equilibrium evaluation process.
[0031] (2) The method of the present invention can evaluate the local thermal equilibrium state for any state and any plasma, with strong versatility.
[0032] (3) The present invention reflects the local thermal equilibrium state through the power exponent, quantifying the degree of deviation of the plasma from local thermal equilibrium. Description of the Drawings
[0033] Figure 1 It is a schematic flowchart of the method of the present invention;
[0034] Figure 2 It is the curve fitting result of the present invention;
[0035] Figure 3 It is the time evolution of the plasma parameter v of the present invention. Detailed Embodiments
[0036] The present invention will be described in detail below with reference to the drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and gives detailed implementation manners and specific operation processes, but the protection scope of the present invention is not limited to the following embodiments.
[0037] Example 1
[0038] This example provides a method for evaluating the local thermal equilibrium of a plasma. As Figure 1 shown, this method includes the following steps:
[0039] S1. Obtain more than 3 spectra of the same element in the plasma.
[0040] The above spectra are characteristic atomic spectra of the same element, and the spectra include spectral intensity and upper-level energy. In this example, if more than 3 spectra are used, there will be multiple different spectral intensities and upper-level energies. The energy difference between the upper levels of the spectra should be greater than 0.5 electron volts (eV) to prevent the data points for power-law fitting in subsequent steps from being very close, resulting in a decrease in the accuracy and reliability of the fitting results, and further affecting the accuracy of the plasma state evaluation results. The types of elements in the plasma include hydrogen H, helium He, nitrogen N, oxygen O, argon Ar, krypton Kr, xenon Xe, neon Ne, radon Rn, metal elements, and halogen elements.
[0041] The characteristic atomic spectra of the plasma used in this example include: Cu I 427.51nm, Cu I 465.11nm, Cu I 510.55nm, Cu I 515.32nm, Cu I 521.82nm, and their upper-level energies are 7.7380eV, 7.7380eV, 3.8171eV, 6.1919eV, and 6.1928eV, respectively.
[0042] S2. Substitute the spectral intensity of the characteristic atomic spectral line into Formula 1 for calculation.
[0043] The spectral intensity is the integral of the spectral line intensity. Substitute the integral of the spectral line intensity into the following Formula 1 to obtain:
[0044]
[0045] In the formula: I nm is the spectral intensity of the transition energy levels n and m, λ is the wavelength of the transition energy levels n and m, A nm is the transition probability of the energy levels n and m, and g n is the degeneracy of the upper level n.
[0046] S3. Perform power-law fitting on Formula 1 and E n to obtain the power exponent v.
[0047] According to existing fitting tools, including Curve Fitting in Matlab, etc., only need to perform power-law fitting on the upper-level energy E n and Formula 1 to obtain the power exponent v.
[0048] The form of power-law fitting is:
[0049]
[0050] Where: I nm is the spectral intensity of the transition energy levels n and m, λ nm is the wavelength of the transition energy levels n and m, A nm is the transition probability between energy levels n and m, g n is the degeneracy of the upper energy level n, z is the charge state, E n is the energy of the upper energy level n, k is the Boltzmann constant, T is the temperature, v is the power exponent, Γ is the gamma function, h is the Planck constant, c is the speed of light in vacuum, N is the particle number density, U(T) is the partition function. In the fitting, A and C can be regarded as constants.
[0051] The power exponent fitting is as Figure 2 shown, the abscissa is the upper energy level energy E n , with the unit of electron volts (eV), and the ordinate is formula 1 The dots are data points, and the solid line is the result of the power exponent fitting.
[0052] S4. Evaluate the local thermal equilibrium state of the plasma according to the power exponent value.
[0053] The method for evaluating the local thermal equilibrium state of the plasma using the power exponent v is as follows:
[0054] When the plasma is in the local thermal equilibrium state, the particles inside the plasma satisfy the Boltzmann distribution. At this time, the parameter v = 1. When the plasma gradually deviates from the local thermal equilibrium, the number of particles in the upper energy level decreases and the spectral intensity weakens, which will cause the curve to gradually become in the form of a power exponent curve, and the parameter v will gradually increase. Through the parameter v, the degree to which the plasma deviates from the local thermal equilibrium can be known.
[0055] Therefore, when the power exponent v is close to 1, the plasma satisfies the local thermal equilibrium condition; when the power exponent v is greater than 1, the plasma deviates from the local thermal equilibrium, and the larger the v value, the more obvious the deviation of the plasma from the local thermal equilibrium.
[0056] As shown by Figure 2 , the fitting degree R 2 is 0.9712. The larger the R 2 , the higher the fitting degree and the better the fitting effect; the parameter v is 1.049, the fitting effect is relatively high, and the plasma satisfies the local thermal equilibrium condition.
[0057] This embodiment also obtains the time evolution of the plasma parameter v at 10 5 Pa, 10 4 Pa, 10 3 Pa asFigure 3 As shown, they are the dotted lines and dashed lines in the figure respectively, and the dashed lines are curve fittings. It can be seen that 5 The parameter v of [[Pa]] is the smallest, 3 The parameter v of [[Pa]] is the largest, 5 The plasma of [[Pa]] is closer to satisfying the local thermal equilibrium condition, and deviates from the local thermal equilibrium condition more slowly with the increase of the delay time. 3 The plasma of [[Pa]] deviates from the local thermal equilibrium most significantly, and deviates from the local thermal equilibrium condition faster with the increase of the delay time.
[0058] Example 2
[0059] This example provides a plasma local thermal equilibrium evaluation system, including:
[0060] Spectrum acquisition module: used to acquire multiple characteristic atomic spectra of the same element of the plasma, and the characteristic atomic spectra include spectral intensity and upper energy level;
[0061] Fitting module: used to calculate and perform power exponent fitting respectively based on the spectral intensity and upper energy level to obtain the power exponent;
[0062] Evaluation module: used to evaluate the local thermal equilibrium state of the plasma according to the power exponent.
[0063] The rest is the same as in Example 1.
[0064] Example 3
[0065] This example provides an electronic device, including: one or more processors; a memory; and one or more programs stored in the memory, and the one or more programs include instructions for executing the plasma local thermal equilibrium evaluation method as described in Example 1 above.
[0066] If the above functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. And the aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.
[0067] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code. The solutions in the embodiments of the present invention can be implemented in various computer languages. For example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript, etc.
[0068] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for realizing the functions specified in one Figure 1 flow or multiple flows and / or blocks Figure 1 block or multiple blocks.
[0069] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing devices to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means realizes the functions specified in one Figure 1 flow or multiple flows and / or blocks Figure 1 block or multiple blocks.
[0070] These computer program instructions can also be loaded onto a computer or other programmable data processing devices, so that a series of operation steps are executed on the computer or other programmable devices to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable devices provide steps for realizing the functions specified in one Figure 1 flow or multiple flows and / or blocks Figure 1 block or multiple blocks.
[0071] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.
[0072] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.
Claims
1. A method for evaluating local thermal balance of plasma, characterized in that: The following steps are involved: Acquire multiple characteristic atomic spectra of the same element of the plasma, wherein the characteristic atomic spectra include spectrum intensity and upper energy level energy; Based on the spectral intensity and the upper energy level energy, a power exponential fitting is performed to obtain a power exponent; The local thermal equilibrium state of the plasma is evaluated based on the power exponent.
2. A plasma local thermal balance assessment method according to claim 1, characterized in that: The step of performing power exponential fitting comprises: Substituting the spectral intensity into formula 1): According to formula 1) and E n Perform power exponential fitting and obtain the power exponential fitting form: Where: I nm is the spectral intensity of transition levels n and m, λ nm is the wavelength of the transition energy levels n and m, A nm is the transition probability between energy levels n and m, g n is the degeneracy of the upper energy level n, z is the charge state, E n is the energy of the upper energy level n, k is the Boltzmann constant, T is the temperature, v is the power exponent, Γ is the gamma function, h is the Planck constant, c is the speed of light in vacuum, N is the particle number density, U(T) is the partition function, and in the fitting, A and C can be regarded as constants.
3. A plasma local thermal balance assessment method according to claim 1, characterized in that: The upper energy level energy difference between the characteristic atomic spectra is greater than 0.5 eV.
4. A plasma local thermal balance assessment method according to claim 1, characterized in that: The number of the characteristic atomic spectra is more than 3.
5. A plasma local thermal balance assessment method according to claim 1, characterized in that: The evaluating the local thermal equilibrium state of the plasma comprises the following: It is determined whether the power index is equal to 1 or greater than 1. If it is equal to 1, it is determined that the plasma satisfies the local thermal equilibrium state. If it is greater than 1, it is determined that the plasma does not satisfy the local thermal equilibrium state.
6. A plasma local thermal balance assessment method according to claim 1, characterized in that: The element types of the plasma include hydrogen H, helium He, nitrogen N, oxygen O, argon Ar, krypton Kr, xenon Xe, neon Ne, radon Rn, metal elements and halogen elements.
7. A plasma local thermal balance assessment method according to claim 1, characterized in that: The spectral intensity is the integrated spectral line intensity.
8. A plasma local thermal balance assessment system, characterized in that: include: Spectrum acquisition module: used to obtain multiple characteristic atomic spectra of the same element of plasma, wherein the characteristic atomic spectra include spectrum intensity and upper energy level energy; Fitting module: used for calculating and fitting the power exponent based on the spectral intensity and the upper energy level energy, respectively, to obtain the power exponent; Evaluation module: used for evaluating the local thermal equilibrium state of plasma according to the power index.
9. An electronic device, characterized in that: include: one or more processors; Memory; and One or more programs stored in a memory, wherein the one or more programs include instructions for executing the plasma local thermal balance estimation method according to any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that: The method comprises one or more programs for execution by one or more processors of an electronic device, wherein the one or more programs comprise instructions for executing the method for evaluating the local thermal balance of plasma according to any one of claims 1 to 7.