Electromagnetic Pulse Research Articles

Numerical Simulation Study of Electromagnetic Pulse in Low-Altitude Nuclear Explosion Source Regions

A nuclear electromagnetic pulse (NEMP) is the fourth effect of a nuclear explosion, characterized by a strong electromagnetic field that can instantly damage electronic devices. To investigate the spatial field value distribution characteristics of the source region of low-altitude NEMPs, this study employed a finite-difference time-domain (FDTD) method based on a rotating ellipsoidal hyperbolic coordinate system. Due to intense field variations near the explosion center, non-uniform grids were employed for both spatial and temporal steps, and an OpenMP parallel algorithm was utilized to enhance computational efficiency. Analysis focused on the following two scenarios: varying angles at a constant distance and varying distances at a constant angle, considering both transverse magnetic (TM) and transverse electric (TE) waves. The results indicate that the spatial field value distribution characteristics differ between the two wave types. For TM waves, the electric and magnetic fields share the same polarity, but their waveform polarities are opposite above and below the explosion center. A TE wave is exactly the opposite. Compared with a TM wave, a TE wave has stronger peak electromagnetic fields but narrower pulse widths and lower overall energy. This research provides significant support for the development of nuclear explosion detection technology and offers theoretical foundations for the protection of surrounding environmental facilities.

Design and Testing of MEMS Component for Electromagnetic Pulse Protection.

With the demand for high-safety, high-integration, and lightweight micro- and nano-electronic components, an MEMS electromagnetic energy-releasing component was innovatively designed based on the corona discharge theory. The device subverted the traditional device-level protection method for electromagnetic energy, realizing the innovation of adding a complex circuit system to the integrated chip through micro-nanometer processing technology and enhancing the chip's size from the centimeter level to the micron level. In this paper, the working performance of the MEMS electromagnetic energy-releasing component was verified through a combination of a simulation, a static experiment, and a dynamic test, and a characterization test of the tested MEMS electromagnetic energy-releasing component was carried out to thoroughly analyze the effect of the MEMS electromagnetic energy-releasing component. The results showed that after the strong electromagnetic pulse injection, the pulse breakdown voltage of the MEMS electromagnetic energy-releasing component increased exponentially in terms of the pulse injection voltage, and the residual pulse current decreased significantly from one-third to one-half of the original, representing a significant protective effect. In a DC environment, the breakdown voltage of the needle-needle structure of the MEMS electromagnetic energy-releasing component was 144 V, and the on-time was about 0.5 ms.

Multi-parameters optimization and failure modes investigation of Al/Mg electromagnetic pulse welded joints

Multi-parameters optimization and failure modes investigation of Al/Mg electromagnetic pulse welded joints

Large area ionospheric D region height determination method based on lightning electromagnetic pulse

Large area ionospheric D region height determination method based on lightning electromagnetic pulse

Improvement of Unmanned Aerial Vehicles model under surge of Lightning Electromagnetic Pulse developed using Artificial Intelligence based on laboratory measurements in reference to classical regression methods

Unmanned aerial vehicles (drones) are increasingly used in a growing number of applications, both civil and military. Their design is based on low weight, making the presence of shielding a difficult decision between safety and weight. Currently, there are no mathematical models to determine the safety of drones operating near a storm front. Lightning causes an electromagnetic wave of an impulse nature, which may pose a real threat to electronic systems. This work attempts to develop a mathematical model for simulating drones safety in terms of electromagnetic pulses using artificial intelligence-based tools. Actual measurement results collected from four drones were used as training data. They were tested in laboratory conditions using specialized measuring equipment used to test avionics in accordance with international standards such as DO-160. A repeatable surge pulse generator and a data acquisition system allowed us to collect information on how overvoltages propagate inside the drone’s systems. Systems that directly influence its operation were selected for this purpose, such as the power supply system, engine controllers, GPS system, camera and data bus lines. Other works show that most overvoltages are induced in motor coils and antennas. On this basis, a number of formulas and equations were developed to describe the most important elements of the drone, without which its correct operation will not be possible. The results of the analyzes and the mathematical model of the drone based on the examined cases are presented in this work as a complement to real experiments.

Correlation of Laser-Accelerated Electron Energy with Electromagnetic Pulse Emission from Thin Metallic Targets

High-power pulsed lasers are used more and more as tools for particle acceleration. Characterization of the accelerated particles in real-time and monitoring of the electromagnetic pulses (EMPs) during particle acceleration are critical challenges in laser acceleration experiments. Here, we used the CETAL-PW laser facility at NILPRP for particle acceleration from different thin metallic targets, at laser intensities of the order of 3×1021 W/cm2. We investigated the dependence of EMP amplitude (EMPA) and the accelerated electrons’ maximal energy (AEME), on thickness, resistivity, and atomic number of the target. We have found a quasi-linear dependence between EMPA and AEME and propose an analytical model for the GHz EMP emission. The model considers the neutralization current flowing through the target stalk as the main source of the EMP in the GHz domain, the current being produced by the positive charge accumulated on the target after the electron’s acceleration from the rear side of a metallic target. The data presented here support the possibility of using EMP signals to characterize the laser-accelerated particles in a real-time non-invasive way.

Electromagnetic radiation attenuation materials

The shielding electromagnetic (EM) waves is a very important field of the electronics, telecommunications and IT industries. The phenomenon of electromagnetic interference (EMI) can be a source of interference in electronic systems, which can both disrupt the operation of systems and provide a breach to intercept the flow of classified information. Hence, it is necessary to shield electronic and IT systems to prevent the coupling of circuits and prevent the monitoring of data emitted in the form of electromagnetic waves. An additional threat resulting from the EMI phenomenon is the possibility of inducing high voltages and currents in circuits that may temporarily or permanently damage electronic systems as a result of high-power electromagnetic pulses. Examples of sources of high-power impulses can be, for example, atmospheric discharges, gasoline engine ignition systems, electrostatic discharges, solar discharges, cosmic rays and military hardware, such as electromagnetic directed energy weapons. The paper will present the results of research carried out as part of interdisciplinary projects related to security threats to ICT systems in the area of critical infrastructure.

Vacuum pair production in zeptosecond pulses: Peculiar momentum spectra and striking particle acceleration by bipolar pulses

We examine the phenomenon of electron-positron pair production from vacuum in a combination of two counterpropagating electromagnetic pulses having a duration of the order of the Compton time. We show that in this extreme short-time domain, the momentum distributions of the particles produced possess a peculiar structure which strongly depends on whether the electromagnetic pulses have a unipolar or bipolar profile. It is shown that bipolar pulses can predominantly generate particles with ultrarelativistic velocities along the propagation direction of the pulses, while unipolar ones are generally more favorable in terms of the total particle yield in the same regime. The highly nontrivial properties of the e+e− spectra revealed in our study provide strong experimental signatures paving the way to probe a complex vacuum response within the short-time domain of quantum electrodynamics. Published by the American Physical Society 2024

Microstructure and Mechanical Properties of Steel/Lead Bi-Metal Tubes Produced by Magnetic Pulse Welding

According to the binary phase diagram, Fe-Pb are immiscible under equilibrium conditions and are hard to metallurgically bond. To solve this problem, in this work, the instantaneous high-temperature and high-pressure environments generated during electromagnetic pulse welding (MPW) were utilized to achieve the miscibility of Fe and Pb, enabling the effective bonding of Fe-Pb bi-metallic tubes. The effects of MPW parameters, including discharge voltage and radial gap, on interfacial bond strength and microstructure were analyzed. Optimal bonding occurred at 10.5 kV discharge voltage and a 1.6 mm radial gap, forming a continuous transition layer. Lower energy input reduced bond strength, while excessive energy caused shear deformations. Microstructure analysis revealed that the diffusion zone significantly enhanced the bond strength. Measured bond strength values were 7.6 MPa at optimal conditions. These results demonstrate that MPW is a feasible method for fabricating Fe-Pb bi-metal tubes, offering a promising way for immiscible metals metallurgical welding.

Assessment of molecular modulation by multifrequency electromagnetic pulses to preferably eradicate tumorigenic cells

Physics methods of cancer therapy are extensively used in clinical practice, but they are invasive and often confront undesired side effects. A fully new equipment that allows sustained emission of intense and time-controlled non-ionizing multifrequency electromagnetic pulse (MEMP), has been applied to eukaryotic cells in culture. The equipment discriminates the overall electronegative charge of the cell cultures, and its subsequent proportional emission may thereby become higher and lethal to cancer cells of generally high metabolic activity. In contrast, low tumorigenic cells would be much less affected. We tested the specificity and efficacy of the equipment against a collection of (i) highly tumorigenic cells of human (glioblastoma, cervical carcinoma, and skin) and mouse (colon adenocarcinoma) origin; (ii) cell lines of much lower tumorigenicity (non-human primate kidney and mouse fibroblasts), and (iii) primary porcine macrophages lacking tumorigenicity. Time and intensity control of the MEMP allowed progressive decay of viability fairly correlating to cell tumorigenicity, which was provoked by a proportional alteration of the cytoplasmic membrane permeability, cell cycle arrest at G2, and general collapse of the actin cytoskeleton to the perinuclear region. Correspondingly, these effects drastically inhibited the proliferative capacity of the most tumorigenic cells in clonogenic assays. Moreover, MEMP suppressed in a dose-dependent manner the tumorigenicity of retrovirally transduced luciferase expressing colon adenocarcinoma cells in xenografted immune-competent mice, as determined by tumor growth in a bioluminescence imaging system. Our results support MEMP as an anti-cancer non-invasive physical treatment of substantial specificity for tumorigenic cells with promising therapeutic potential in oncology.

Electromagnetic theory: Electromagnetic pulse in the laboratory

This article shows the process in the development of a laboratory practice of Electromagnetic Theory, applied to the Telecommunications, Systems and Electronics Engineering Career, of the Facultad de Estudios Superiores Cuautitlán (FESC) belonging to the Universidad Nacional Autónoma de México (UNAM). The objective for future engineers is to learn about the impact of an electromagnetic pulse on electronic equipment. It begins with the theoretical background of the electromagnetic pulse, then basic oscillator circuits are addressed and an experiment with a low-power electromagnetic pulse is developed. The impact of the practice on the students is measured and with it, conclusions are drawn, indicating the importance of this knowledge for future engineers in telecommunications systems and electronics.

Discussion on the reverse recovery characteristics and protection methods of high-power silicon stack in electromagnetic railgun pulse forming network

Abstract In response to the problem of adverse effects on circuit elements caused by the reverse recovery characteristics of electromagnetic railgun freewheeling silicon stack during the sequential discharge process of pulse forming network, this paper uses the existing diode reverse recovery model and simulates the I-t and U-t change curves during the diode reverse recovery process through numerical calculation methods, obtaining results that are consistent with expectations. And through the pulse forming network composed of two modules in parallel, the changes in load voltage during the PFN timing discharge process were analyzed, and the impact of the reverse recovery process of the freewheeling diode on the power module was analyzed. Explored the influence of storage time and recovery time on the peak reverse current and maximum current change rate during reverse recovery process, and verified the correctness of the theory that if the reverse recovery time is too short, it can also cause damage to semiconductor components in the circuit.

Simulation and experimental study on the use of shaped charge jet as transient antennas for radiating electromagnetic pulses

Simulation and experimental study on the use of shaped charge jet as transient antennas for radiating electromagnetic pulses

Observation of spatiotemporal dynamics for topological surface states with on-demand dispersion

Dispersion management in guided wave optics is of vital importance for various applications. Topological photonics opens new horizons for manipulating unidirectional guided waves utilizing edge states. However, the experimental observation of spatiotemporal dynamics for guided waves with on-demand dispersion in topological photonic crystal is an important issue awaiting exploitation. Herein, we experimentally investigate the spatiotemporal properties of topological surface states with on-demand dispersion, where they are supported by a truncated valley photonic crystal with surface modulation. We observe the electromagnetic dynamics of surface states with typical dispersions, where dynamical trapping of an electromagnetic pulse mediated by the unidirectional surface state with flat dispersion and backward beam routing using reversed dispersion properties are achieved in photonic crystal slabs. Both numerical and experimental results substantiate the ultimate dispersion management for topological surface states, which could pave new ways for the manipulation of electromagnetic waves on the surface of photonic devices.

The Threats and Research Prospects of High-Altitude Electromagnetic Pulse on Power Facilities

The Threats and Research Prospects of High-Altitude Electromagnetic Pulse on Power Facilities

An Advanced High Power Electromagnetic Pulse Generator with High Repetition Frequency

Abstract In this paper, an electromechanical pulse power source with repetitive frequency based on piezoelectric ceramic array and miniature plasma diode is introduced, which drives the piezoelectric ceramic array with an electromechanical system to generate a high-voltage pulse, which can generate strong electromagnetic radiation power after interacting with the gaseous medium plasma in the miniature plasma diode. This pulse power source can produce high output energy gain by using low-power DC power supply, and the pulse repetition frequency can be electronically adjusted by adjusting the motor speed. This pulse power source also has the advantages of compact structure and low cost, with a wide range of application prospects.

Design and Experiment of Electromagnetic Pulse Protection Circuit for RF Front End

Abstract This paper introduces the structure and working principle of electromagnetic pulse protection circuit in VHF frequency band in detail. Based on this, a protection circuit with multilevel filtering and transient suppression function is designed. The filter function of the device is realized through a five-order coaxial filter, while the transient suppression feature is accomplished using TVS devices. In order to guarantee the power capacity, the input and output ports of the circuit use N-type connector. Due to good design, the operating bandwidth of the protection circuit exceeds 1.3GHz and the insertion loss is less than 0.5dB. The protective performance of this device was tested by sub-nanosecond solid-state pulse source. The experimental results show that the peak power of electromagnetic protection circuit is greater than 700kW, the suppression capacity is more than 33dB, and the response time is better than 1.4ns.

Helping Physicians to Understand "Havana Syndrome" and a Novel Method of Managing AHIs

Never before have civilian physicians encountered patients with, or were challenged with diagnosing a chronic conditionnamed “Havana Syndrome” and its acute events known as Anomalous Health Incidents (AHI). Furthermore, there are no therapeutic interventions exist to manage debilitating symptoms of AHI. The aim of this paper is two-fold. First, the author provides aframework for understanding these phenomena: brain entrainment and non-kinetic brain injury. Second, a promising method of managing AHIs of "Havana Syndrome" is described, and effectiveness demonstrated by the author. The method utilizes two percussive massagersset to different pulsating frequencies used simultaneously in order to de-synchronize brain activity subjected to exogenous electromagnetic pulses.

Locating Strong Electromagnetic Pulses Recorded by a Single Satellite with Cluster Analysis and Worldwide Lightning Location Network Observations

The integration of satellite-borne and ground-based global lightning location networks offers a better perspective to study lightning processes and their evolutionary characteristics within thunderstorm clouds, thereby bolstering the predictive capabilities for severe weather phenomena. Currently, the satellite-borne network is in the preliminary testing phase with a single satellite. The geographic locations of single-satellite detection events primarily rely on synchronous information from coincident ground-based network events; this method is called synchronous locating (SCL). However, variations in detection-frequency bands and system capabilities prevent this method from accurately locating more than a mere 10% of events. To address this limitation, this paper introduces a cluster-analysis-based strategy, utilizing the observations from the Worldwide Lightning Location Network (WWLLN), termed the cluster analysis locating (CAL) method. The CAL method’s performance, influenced by the density-based spatial clustering of applications with noise (DBSCAN), the K-means, and the mean shift algorithms, is examined. Subsequently, an advanced version, mean shift denoised (MSDN)-CAL, is proposed, demonstrating marked improvements in location accuracy and reliability over the other CAL methods. The satellite-borne wideband electromagnetic pulse detector (WEMPD), orbiting at an altitude of approximately 500 km with a 97.5° inclination, captured 1061 strong electromagnetic pulses (EMPs). Among these, trans-ionospheric single pulses (TISPs) and trans-ionospheric pulse pairs (TIPPs) constituted 21.30% and 78.70%, respectively. Using the MSDN-CAL method successfully determines the geographic locations for 81.15% (861 out of 1061) of the events. This success rate represents an approximate eightfold enhancement over the SCL method. The arithmetic mean, geometric mean, and standard deviation of the two-dimensional range deviation of the locating results between the MSDN-CAL method versus the WWLLN-SCL (or the Guangdong-Hong Kong-Macao Lightning Location System (GHMLLS)-SCL) method are 51.06 (176.26) km, 16.17 (92.53) km, and 100.95 (174.79) km, respectively. Furthermore, it has been possible to estimate the occurrence altitudes for 81.92% (684 out of 835) of the TIPP events. The altitude deviations, as determined by comparing them with the GHMLLS-SCL method’s locating results, exhibit an arithmetic mean of 2.08 km, a geometric mean of 1.30 km, and a standard deviation of 2.26 km. The outcomes of this research establish a foundation for deeper investigation into the origins of various event types, their seasonal variations, and their geographical distribution patterns. Moreover, they pave the way for utilizing a single satellite to measure global surface reflectance, thus contributing valuable data for meteorological and atmospheric studies.

Wavy interface formation mechanism during magnesium–aluminum electromagnetic pulse welding

The wavy interface and its formation mechanism in magnesium–aluminum joints fabricated by electromagnetic pulse welding are investigated. This work reveals the wavy interfaces are produced by the shock wave-induced Kelvin–Helmholtz (K–H) instability. The shock wave generated at the collision point propagates forward along the collision angle and undergoes refraction and reflection at the boundaries, reaching the bonding interface and causing disturbances. It leads to K–H instability at the bonding interface, periodically generating waves. The re-reflection of the shock wave also leads to the secondary K–H instability, which creates the secondary wave with a smaller amplitude on the original wave. Based on this principle, a shock wave-induced K–H instability simulation model was also established to predict the wavy interface length.