System for generating MV / m giant electromagnetic pulse excited by high-power laser

Abstract

According to the high-power laser excitation MV / m giant electromagnetic pulse generation system provided by the invention, double picosecond laser pulses are adopted to interact with the gold target, the peak field intensity of the generated electromagnetic pulses reaches 3.08 MV / m, the controllability is high, the energy conversion efficiency is high, and the energy conversion efficiency is high. The device can be applied to various fields such as electromagnetic protection research, high-power microwave and directional energy weapon research and special electromagnetic environment simulation, and has relatively high environmental adaptability and wide application prospects; meanwhile, by adopting the double-picosecond laser pulse technology, the dependence on high-cost and high-energy-consumption laser equipment is remarkably reduced, so that the equipment purchase, operation and maintenance cost is effectively reduced, and the economical efficiency and the practical value of the technology are greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic pulse generation technology, and particularly relates to a system for generating MV / m giant electromagnetic pulses excited by a high-power laser. Background Technology

[0002] High-power electromagnetic pulse (EMP) technology has significant application value in electromagnetic protection testing, high-power microwave systems, electronic warfare, and simulation of special electromagnetic environments. Traditional EMP generation methods mainly rely on high-voltage pulse power supplies, explosive magnetic compression devices, or pulse power systems based on semiconductor switches. However, these technologies generally suffer from limitations such as field strength (typically below several hundred kV / m), poor pulse waveform controllability, large system size, or low repetition frequency, making it difficult to meet the application requirements of modern high-field-strength, high-precision electromagnetic pulses.

[0003] In recent years, laser-plasma interaction has provided new insights into the generation of high-power electromagnetic pulses (EMPs). The interaction of a powerful laser with matter can excite transient high-density plasmas, generating strong electromagnetic radiation through photoionization, electron acceleration, or target current loop coupling. However, existing laser-driven EMP technologies still face bottlenecks such as low energy conversion efficiency (typically <1%), insufficient pulse field strength (generally on the order of kV / m), and poor radiation directionality. For example, laser-induced EMP schemes reported in the literature often rely on complex target structures (such as metal arrays or resonant cavities), and their electromagnetic pulse amplitude is limited by the target size and laser energy, making it difficult to break through the MV / m range. While methods based on laser-gas-plasma interaction can generate broadband radiation, the field strength is weak and energy dissipation is severe. Furthermore, existing technologies lack effective means to control the pulse waveform (such as rise time and pulse width), limiting their application in precision electromagnetic testing.

[0004] Therefore, there is an urgent need to develop a method for generating MV / m-level giant electromagnetic pulses using a high-power laser. By optimizing laser parameters, target design, and energy coupling mechanisms, key problems such as insufficient field strength, low efficiency, and uncontrollable waveforms in existing technologies can be solved. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a system for generating MV / m giant electromagnetic pulses using a high-power laser. By using a dual picosecond pulsed laser interacting with a gold target, a radiation environment capable of generating MV / m-level giant electromagnetic pulses can be created.

[0006] A system for generating high-power laser-excited MV / m giant electromagnetic pulses includes a dual picosecond pulse laser assembly, a gold target, an EMP probe, and an oscilloscope.

[0007] The dual picosecond pulsed laser assembly generates a 100-joule-level dual picosecond pulsed laser, which is incident on the gold target, causing the gold target to generate a giant electromagnetic pulse at the MV / m level under the action of the dual picosecond pulsed laser; the EMP probe is used to send the sampled giant electromagnetic pulse to the oscilloscope, and the oscilloscope records and displays the transient signal waveform of the giant electromagnetic pulse.

[0008] Furthermore, the dual picosecond pulsed laser assembly comprises two picosecond lasers. The dual picosecond pulsed laser, composed of picosecond lasers emitted simultaneously from the two picosecond lasers, has an energy of 800 J, a wavelength of 1053 nm, a pulse duration of 2 ps, and a focal spot power density of 2.9 × 10⁻⁶. 19 W / cm 2 .

[0009] Furthermore, the shape and size of the gold target are designed according to specific experimental requirements to accommodate samples or experimental equipment of different sizes.

[0010] Furthermore, a dual picosecond pulsed laser is incident on the surface of the gold target at a 24° angle.

[0011] Furthermore, the EMP probe is positioned 60cm away from the gold target surface.

[0012] Furthermore, the thickness of the gold target is 10 μm.

[0013] Furthermore, a system for generating a high-power laser-excited MV / m giant electromagnetic pulse also includes an electron spectroscopy instrument for measuring the hot electron distribution within the vacuum target chamber where the gold target is located.

[0014] Beneficial effects:

[0015] 1. This invention provides a high-power laser-excited MV / m giant electromagnetic pulse generation system. It uses a dual picosecond laser pulse interacting with a gold target to generate an electromagnetic pulse with a peak field strength of 3.08 MV / m. It has strong controllability and high energy conversion efficiency. It can be applied to various fields such as electromagnetic protection research, high-power microwave and directed energy weapon research, and special electromagnetic environment simulation. It has strong environmental adaptability and broad application prospects.

[0016] 2. This invention provides a system for generating MV / m giant electromagnetic pulses excited by a high-power laser. By increasing the laser focusing power density, the intensity of the electromagnetic pulse is significantly improved, enabling effective control of the complex radiation environment generated in the target chamber of a picosecond kilojoule-level large laser device.

[0017] 3. This invention provides a system for generating MV / m giant electromagnetic pulses excited by a high-power laser. It can obtain the required high-intensity electromagnetic pulses without relying on extremely high-power laser equipment, thereby effectively reducing the dependence on high-energy laser equipment. This directly reduces the purchase cost, operating cost, and subsequent maintenance cost of the equipment, greatly improving the feasibility and practicality of this invention in practical applications, and laying a solid foundation for the promotion and application of electromagnetic pulse technology in more fields.

[0018] 4. This invention provides a system for generating MV / m giant electromagnetic pulses excited by a high-power laser. The gold target has excellent electrical conductivity, thermodynamic stability, high atomic number, excellent chemical inertness, good processability, and good experimental repeatability, which is beneficial to enhancing the coupling efficiency between the laser and the target material, so as to ensure the accuracy and repeatability of experimental conditions. Attached Figure Description

[0019] Figure 1 A schematic diagram of a high-power laser-excited MV / m giant electromagnetic pulse generation system provided by the present invention;

[0020] Figure 2 Electron distribution diagrams under different laser conditions provided for this invention;

[0021] Figure 3 The voltage and electric field intensity signal diagrams obtained from the dual picosecond pulses provided by this invention;

[0022] Figure 4 This is a schematic diagram comparing the EMP intensity obtained by different laser devices provided by the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0024] A system for generating high-power laser-excited MV / m giant electromagnetic pulses includes a dual picosecond pulse laser assembly, a gold target, an EMP probe, an oscilloscope, and an electron spectrometer.

[0025] The dual picosecond pulsed laser assembly generates a 100-joule-level dual picosecond pulsed laser, which is incident on the gold target, causing the gold target to generate a giant electromagnetic pulse at the MV / m level under the action of the dual picosecond pulsed laser; the EMP probe is used to send the sampled giant electromagnetic pulse to the oscilloscope, which records and displays the transient signal waveform of the giant electromagnetic pulse; the electron spectrometer is used to measure the hot electron distribution in the vacuum target chamber where the gold target is located.

[0026] It should be noted that this invention is implemented based on the SG-II UP large-scale laser device platform. This device, as a leading high-power laser experimental platform in China, possesses the unique capability to output dual high-energy, ultra-high power density picosecond laser pulses, providing ideal experimental conditions for conducting research on high-intensity laser-matter interactions. Specifically, the SG-II UP laser device has a picosecond short-pulse laser beam with a focal spot <25μm and a focusing power density >10. 19 W / cm 2 Signal-to-noise ratio > 10 8 It features a high power density output capability with an adjustable pulse width ranging from 0.5 to 10 ps. It should be noted that the laser parameters of the dual picosecond pulsed laser can be designed according to specific experimental requirements to adapt to different experimental needs.

[0027] For example, during the experiment, the parameters of the dual picosecond laser pulse used in this invention were set according to the following conditions: wavelength of 1053 nm, pulse duration of 2 ps, energy of 800 J, and focal spot power density of 2.9 × 10⁻⁶. 19 W / cm 2 The achievement of these high energy density laser parameters provides the necessary energy input conditions for exciting high-intensity transient electromagnetic pulses. High-purity (99.99%) gold foil was selected as the solid target material in the experiment, and its thickness, measured by an ellipsometer, was 10 μm. The selection of the gold target material was based on the following technical considerations: First, gold has excellent electrical conductivity (resistivity 2.44 × 10⁻⁶). -8 Firstly, the high atomic number of gold (Z=79) is beneficial for the formation of laser-induced plasma current loops. Secondly, gold materials exhibit good thermodynamic stability under strong laser irradiation, which can effectively suppress premature ablation of the target material. Thirdly, gold has a high atomic number (Z=79), which is beneficial for enhancing the coupling efficiency between the laser and the target material.

[0028] Experimental layout diagram as follows Figure 1 As shown, the electromagnetic pulse measurement system consists of an EMP probe, an electromagnetically shielded transmission cable, and a high-speed oscilloscope. In dual-picosecond laser beam mode, the EMP probe is positioned 60 cm from the target surface; in single-picosecond laser beam mode, it is positioned 120 cm. All EMP probes are connected to a 4-channel, 6 GHz bandwidth digital storage oscilloscope via double-shielded coaxial cables, with a sampling rate set to 25 Gs / s to ensure complete recording of the EMP transient signal waveform. The experiment uses a 1053 nm wavelength picosecond petawatt laser beam from a neodymium glass laser, which, after focusing, irradiates the planar thin-film target at the center of the target chamber at a precise incident angle of 24° to ensure the controllability of the laser-target interaction and the reliability of the experimental data. The target material is a 10 μm thick gold target, with its surface precisely aligned along the target frame axis, and the positional error controlled within ±0.1 mm. The target chamber is maintained at 10°... -3A vacuum environment of Pa was used to eliminate the influence of air on the experimental results.

[0029] In addition, for comparative research, a comparative experiment was also conducted on the XG-Ⅲ laser device. The laser parameters output by this device were rigorously calibrated: laser pulse energy of 100 J, pulse duration of 1.0 ps, ​​and focal spot power density of 1.3 × 10⁻⁶. 19 W / cm 2 Through comparative analysis Figure 2 The experimental results show that, compared to the XG-Ⅲ laser device, the residual electron density inside the SG-ⅡUP laser device interacting with a 10μm gold target is reduced. This phenomenon clearly indicates that under higher power density laser irradiation, the electron escape efficiency inside the target material is significantly improved. Furthermore, Figure 2 Experimental data in (c) confirm that, under the same experimental conditions of laser pulse duration and focal spot size, the number of escaping electrons increases when the laser energy is increased from 100 J to 800 J. This change directly leads to an increase in electromagnetic pulse intensity. These experimental results provide important experimental evidence for the physical mechanism of high-power laser-induced giant electromagnetic pulses proposed in this invention.

[0030] In this invention, the three experimental data acquisitions for the dual picosecond laser pulse correspond to... Figure 3 The three sets of experimental data are arranged from bottom to top. Figure 3 (a) shows the original voltage signal waveform recorded by an oscilloscope. Figure 3 (b) shows the time-domain distribution of the electric field intensity after calibration transformation (the peak value of the electric field is marked in the upper right corner). Furthermore, Figure 3 (c) The electromagnetic pulse spectrum characteristics obtained by fast Fourier transform processing are presented. Figure 3 (d) shows the synchronously acquired electron energy spectrum distribution data. Analysis Figure 3 (a) It can be seen that the voltage signal exhibits obvious oscillation characteristics and its duration exceeds 200 ns, indicating that the interaction between the laser and the target material generates long-life plasma oscillations. Figure 3 (b) The measurement results show that all three picosecond laser pulses generated electromagnetic pulses with field strengths exceeding 1 MV / m, with the highest peak field strength reaching 3.08 MV / m. It is noted that there are significant differences in the electromagnetic pulse intensities obtained from the three experiments, a phenomenon mainly attributed to variations in the laser focal spot power density. Although the laser energy and pulse duration corresponding to the data collected in the three experiments remained relatively stable, the measured focal spot size fluctuated within a certain range. Based on the inverse square relationship between laser power density and focal spot radius (P∝1 / r²),... 2The small change in the focal spot size leads to a significant difference in power density, and this geometric amplification effect directly explains the difference in electromagnetic pulse intensity between different experimental numbers.

[0031] like Figure 4 As shown, a comprehensive comparison revealed that only dual picosecond pulsed lasers can generate giant electromagnetic pulses at the MV / m level. Giant electromagnetic pulses were generated in all three experiments, which to some extent avoided randomness and errors. At the same time, the energy conversion efficiency of dual picosecond lasers is about 100 times that of single picosecond lasers. The results of this experiment ranked first in the comparison of EMP intensity of picosecond laser devices.

[0032] Therefore, this invention provides a system for generating giant electromagnetic pulses on the order of MV / m using high-power laser excitation. By designing the laser parameters and target materials, the system has stronger environmental adaptability and can be applied to several important technical fields such as electromagnetic compatibility testing, high-power microwave system development, electronic equipment anti-interference evaluation, and simulation of special electromagnetic environments. It provides an effective technical solution to solve the key problems of insufficient field strength, poor environmental adaptability, and limited parameter controllability currently faced by electromagnetic pulse technology.

[0033] In summary, compared with the prior art, the high-power laser-excited MV / m giant electromagnetic pulse generation system provided by the present invention has the following advantages:

[0034] By selecting SG-ⅡUP laser equipment and target materials, the generated MV / m giant electromagnetic pulses can be controlled, which can effectively control the complex radiation environment generated in the target chamber of picosecond kilojoule-level large laser devices. It can be applied to various fields such as electromagnetic protection research, high-power microwave and directed energy weapon research, and special electromagnetic environment simulation, and has strong environmental adaptability.

[0035] This invention successfully achieved a significant increase in EMP intensity by optimizing laser parameters. In the experiment, the interaction between a dual picosecond laser pulse and a gold target generated an electromagnetic pulse with a peak field strength of 3.08 MV / m, which is far higher than that generated by traditional methods. Traditional nanosecond-level laser pulses typically only produce electromagnetic pulses with electric fields reaching hundreds of kV / m. The dual picosecond laser pulse in this invention significantly improves the intensity of the electromagnetic pulse by increasing the laser focusing power density. This high-intensity electromagnetic pulse provides a powerful tool for studying electromagnetic effects under high field strengths and will help promote the application of electromagnetic pulses in multiple fields.

[0036] This invention employs dual picosecond laser pulses to excite electromagnetic pulses, achieving a significant improvement in energy conversion efficiency compared to traditional single-laser configurations, specifically reaching 0.11‰, a 100-fold increase. The benefits of this significantly improved energy conversion efficiency are multifaceted. First, under the same laser energy input conditions, dual picosecond laser pulses can excite much stronger electromagnetic pulses. This means that in practical applications, the required high-intensity electromagnetic pulses can be obtained without relying on extremely high-power laser equipment, effectively reducing dependence on high-energy laser devices. Furthermore, it reduces the need for high-cost, high-energy-consumption laser equipment, directly lowering equipment purchase costs, operating costs, and subsequent maintenance expenses. From an economic perspective, the application of dual picosecond laser pulses makes the electromagnetic pulse generation process more economical and efficient, greatly improving the feasibility and practicality of this invention in real-world applications, and laying a solid foundation for the promotion and application of electromagnetic pulse technology in more fields.

[0037] The implementation of this invention represents a breakthrough in electromagnetic pulse generation technology, positively promoting the development of related fields. For example, in the field of electromagnetic compatibility testing, high-intensity, highly controllable electromagnetic pulses can more accurately assess the anti-interference capabilities of electronic devices; in the field of materials science, strong electromagnetic pulses can be used for material modification research, exploring new material properties and applications; in the field of electromagnetic protection technology, the electromagnetic pulse generation and shielding methods provided by this invention help develop more efficient electromagnetic protection devices and improve the electromagnetic protection capabilities of systems.

[0038] In summary, this invention has achieved significant beneficial effects in terms of improving electromagnetic pulse intensity, enhancing controllability, increasing energy conversion efficiency, and promoting the development of related technologies. It has important scientific value and broad application prospects.

[0039] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A system for generating high-power laser-excited giant electromagnetic pulses (MV / m), characterized in that, Includes a dual picosecond pulsed laser assembly, a gold target, an EMP probe, and an oscilloscope; The dual picosecond pulsed laser assembly generates a 100-joule-level dual picosecond pulsed laser, which is incident on the gold target, causing the gold target to generate a giant electromagnetic pulse at the MV / m level under the action of the dual picosecond pulsed laser; the EMP probe is used to send the sampled giant electromagnetic pulse to the oscilloscope, and the oscilloscope records and displays the transient signal waveform of the giant electromagnetic pulse.

2. The high-power laser-excited MV / m giant electromagnetic pulse generation system as described in claim 1, characterized in that, The dual-picosecond pulsed laser assembly comprises two picosecond lasers. The dual-picosecond pulsed laser, composed of picosecond lasers emitted simultaneously from the two picosecond lasers, has an energy of 800 J, a wavelength of 1053 nm, a pulse duration of 2 ps, and a focal spot power density of 2.9 × 10⁻⁶. 19 W / cm 2 .

3. The system for generating high-power laser-excited MV / m giant electromagnetic pulses as described in claim 1, characterized in that, The shape and size of the gold target are designed according to specific experimental requirements to accommodate samples or experimental equipment of different sizes.

4. The high-power laser-excited MV / m giant electromagnetic pulse generation system as described in claim 1, characterized in that, A dual picosecond pulsed laser is incident on the surface of a gold target at a 24° angle.

5. The system for generating high-power laser-excited MV / m giant electromagnetic pulses as described in claim 1, characterized in that, The EMP probe is positioned 60cm away from the gold target surface.

6. The system for generating high-power laser-excited MV / m giant electromagnetic pulses as described in claim 1, characterized in that, The thickness of the gold target is 10 μm.

7. The system for generating high-power laser-excited MV / m giant electromagnetic pulses as described in claim 1, characterized in that, It also includes an electron spectrometer for measuring the distribution of hot electrons within the vacuum target chamber where the gold target is located.

Images