Electromagnetic Pulse Research Articles

Characteristics of electromagnetic radiation of the veterinary physiotherapy device UMI-05-V

We studied some physical characteristics of the veterinary physiotherapeutic device UMI-V-05. The magnetic induction at different power levels was determined using TPU 02 militeslameter. The magnetic induction was measured for each power value. The probe of the milliteslameter was placed directly on the working surface, in the center of the inductor. It was found that the minimum magnetic induction of the device is 350±6.0 mTl, and the maximum is 1058±10.0 mTl. During the device operation, the heating of the inductor was determined using a thermal imager and a stopwatch. During the recommended time range (10 minutes), the inductor temperature did not exceed 46 °C. Determination of the pulse radiation frequency depending on the magnetic induction value was carried out using a stopwatch. At each working power the number of pulses per minute was counted and the number of pulses per second was calculated (frequency determination). It was revealed that UMI-V-05 is a low-frequency source of pulsed magnetic radiation with the maximum frequency of 1.3 Hz at the minimum magnetic induction of 350±6.0 mTl and the minimum frequency of 0.1 Hz at the maximum magnetic induction of 1058±10.0 mTl. Using a ruler and a TPU 02 milliteslameter, the degree of magnetic pulse attenuation depending on the distance to the working surface of UMI-V-05 was determined, it was fixed that the value of magnetic induction varies inversely proportional to the distance from the inductor. The penetration ability of the electromagnetic pulse through different media: biological and non-biological using TPU 02 militeslameter was studied. Biological tissues (muscle, bone) and some nonbiological media (paper, glass, wood, polyethylene, water) do not affect the passage of the electromagnetic pulse, while steel significantly reduces the passage of the pulse.

Self-driven intelligent curved hinge based on shape-morphing composites

The space deployable structures based on shape memory polymer composites (SMPCs) possessed excellent self-deployable performance, which effectively avoided the impact and electromagnetic pulse (EMP) caused by the explosion of pyrotechnic devices. In this work, two types of self-driven curved hinges with different angles of 80° and 115° (Type 80 and Type 115) were designed based on SMPCs. The thermomechanical properties and time–temperature-dependent viscoelastic behaviors of SMPCs were systematically investigated. The three-point bending performance and cyclic shape memory performance of the developed hinges were also characterized. In addition, the deployment performances of Type 80 driven 350 g object under different heating powers were investigated in the environment of ± 70 °C and 103 Pa atmospheric pressure. A staircase-like heating strategy was proposed to achieve precise and controllable deployment under this environment. The developed self-driven curved hinges were expected to have tremendous application potential on the flap actuators and optical payload rotating platforms of the satellites.

Time-Series Data Augmentation for Improving Multi-Class Classification Performance

This paper proposes a new approach to classify and evaluate defects in concrete structures automatically. To overcome the limitations of defect detection methods that traditionally relied on expert visual observation, the reflection signal of electromagnetic pulses is extracted as time-series data and used to analyze the propagation characteristics of each defect. This study uses deep learning models to analyze these time-series data and classify defects. Since anomaly detection data has more normal data than anomaly data, data augmentation methods such as Time Warping, Noise Injection, Smoothing, Trend Shifting, etc., were applied to solve the problem of data imbalance and overfitting. Among them, Noise Injection showed the best performance. The generalization performance of the proposed method was evaluated through performance evaluation using LSTM, GRU, and TCN models, and LSTM models showed the highest performance. The study results show that the proposed method effectively classifies defect types in concrete structures and can solve the limitations of existing methods by automatic classification through deep learning models. In addition, it was confirmed that the model's performance could be improved by improving the amount and diversity of data by selecting and applying appropriate data augmentation methods. The contribution of the research is to present a new approach that automates the defect detection and classification task of concrete structures and provides high accuracy and efficiency.

Coulomb impurities in graphene driven by ultrashort electromagnetic pulses: excitation, ionization, and pair creation

We provide a theory for electronic transitions induced by ultrashort electromagnetic pulses in two-dimensional artificial relativistic atoms which are created by a charged impurity in a gapped graphene monolayer. Using a non-perturbative sudden-perturbation approximation, we derive and discuss analytical expressions for the probabilities for excitation, ionization and electron-hole pair creation in this system.

Development and Experimental Verification of Inorganic Electromagnetic Pulse Shielding Paint for Building Interiors Using Carbon-Based Materials.

The term electromagnetic pulse (EMP) generally refers to high-power electromagnetic waves and can be classified into EMPs caused by nuclear weapons, non-nuclear EMPs, and EMPs caused by natural phenomena. EMPs can cause catastrophic damage to any electronic device consisting of electromagnetic components, including communications devices and transportation. In this study, the shielding effectiveness of paint was evaluated depending on the type and content of carbon material and binder. To analyze the compatibility and dispersibility improvement of the raw materials used in paint manufacturing, experiments were conducted in two stages, using 27 mixtures. The shielding effectiveness was evaluated for the optimal mixture developed through mixture experiments. The results of this study confirmed that the developed EMP shielding paint can improve the shielding effectiveness of concrete by 25-40 dB. Additionally, the adhesion strength and moisture resistance evaluation of the EMP shielding paint were evaluated. The average adhesive strength of the EMP shielding paint was 1.26 MPa. In moisture-resistance testing at a temperature of 50 ± 3 °C and a relative humidity of 95% or higher for more than 120 h, no cracks or peeling were observed on the painted surface.

Investigation of electromagnetic pulse scattering for metallic object classification using machine learning

ABSTRACT This paper presents a metallic object classification method using various electromagnetic pulses. Each electromagnetic pulse irradiated eight metallic objects placed at increasing distances from 10 mm to 40 mm relative to the electromagnetic sensing system. The electromagnetic sensing system consisted of two RL circuits placed in close proximity. Objects were classified using linear (perceptron and multiclass logistic regression) and non-linear (neural network, 1D convolutional neural network (CNN) and 2D CNN) machine learning classifiers. The machine learning classifiers were trained on experimental data collected in an electromagnetically shielded laboratory. A 10-fold cross-validation mean classification accuracy of 99.4 ± 0.3% for the 1D CNN classifier, and 92.9 ± 1.2% for the 2D CNN classifier, was achieved using a rectangular chirp electromagnetic pulse. The rectangular chirp pulse outperformed two-sided decaying exponential, Gaussian, triangular, raised cosine, and rectangular pulses. All pulses had equal energy. While the rectangular chirp performed best overall, other pulses more accurately distinguished between some objects.

Wood Chipper Design for Biofuel Production in a Global Catastrophic Loss of Infrastructure Scenario

A variety of events such as high-altitude electromagnetic pulses, extreme solar storms, and coordinated cyber attacks could result in a catastrophic loss of infrastructure on a continental or global scale. The lengthy repair of critical infrastructure creates a need for alternative fuels such as wood gas. Wood gas is produced by heating wood in a low-oxygen environment and can be used to power combustion engines. This work investigates a novel wood chipper, designed as an energy-efficient tool for producing wood gas stock, wood chips, aiming to speed up the transition to alternative fuel. A prototype is built and tested to determine the energy efficiency and production rate of the device. The results suggest that the wood chipper could produce one cord of wood chips, 3.6 m3, in less than a day and is a viable alternative to other manual wood-processing methods. In addition, the global scaling up of production of the wood chipper is considered, indicating that the mass production of the wood chipper could accelerate the transition of wood gas production methods from manual to machine-driven immediately after a catastrophic event.

Demonstration of proton acceleration using laser-driven EMP field in dispersion-free slow wave tube

We demonstrate the laser-driven post-acceleration experiment, utilizing a miniature slow-wave structure. Experiments on a terawatt laser system showed a significant increase in proton cutoff energy, highlighting the technique's potential, especially for high-power laser systems. The slow-wave structure consists of a helix and a shielded metallic shell covered on the outside. The transmission properties of electromagnetic pulses (EMPs) generated by laser–foil interactions along the structure are studied. Through an electromagnetic field perspective, we derived dispersion relations for helices with and without metallic shield. Our findings, supported by theory, simulations, and experiments, demonstrate the structure's ability to transmit high-frequency EMPs with limited dispersion.

Subnanosecond Electromagnetic Pulse Generated by a Long Spark Discharge: Lightning Implication

AbstractThe effects of generating pulsed radiation by a long spark discharge are important for the development of lightning models and applications related to lightning protection. In experiments with a Marx generator simulating a lightning discharge, we detected the radiation in the form of a single ultrawideband electromagnetic pulse (UWB EMP) about 200 ps in duration, and rising time about 100 ps. UWB EMP generation occurs during the breakdown of a “rod–rod” 4 m long gap. Pulses of almost unipolar shape are observed in more than half of all positive discharges. EMP emission occurs before the main stage, and corresponds to the start of the upward leader from a grounded electrode. In negative discharges, pulses are also observed, but less frequently and with a smaller amplitude. The UWB EMPs, given their large amplitude (more than 100 V/m at a distance of 90 m from the discharge), can be considered as possible new lightning damage factors.

A New Strategy is Needed to Solve the 50-Year-Old Problem - EMP Protection of Critical Civilian Infrastructure

The problem of the destructive effects of High-Altitude Electromagnetic Pulse (HEMP or EMP) on electronic and electrical equipment has been well known for more than 50 years. All military equipment and critical equipment of special governmental services are reliably protected from such influences. There are many companies on the market that manufactures numerous EMP protection means that meet the requirements of military standards. It would seem that in such a situation, critical civilian infrastructure facilities (electrical power systems, water supply systems, communications, large medical centers, banks, etc.) should also be protected against EMP. But it turns out that this is not the case! Nowhere in the world are critical civilian infrastructure still protected from such impacts! Why? The main reason is an attempt to use well-known military strategies, methods and protection means for protecting civilian infrastructure. This article proposes new protection strategies and methods for the civilian sector.

Vulnerabilities of water-energy and food nexus in cities of digital era

The edifice of civilization stands on water-energy-food nexus, speech, trading management and complexity. This paper, presents a mini review of these issues which are the foundations of civilization, and discusses their role in social prosperity. Recent year public discussion emerges that an electromagnetic pulse (EMP) could strike cities due to natural or artificial reasons therefore, we attempt to describe the impact of an EMP from the viewpoint of civil engineering. To do so, we analyze the fundamental parts of civilization in present, their roles, and their functions. Analysis estimates that an EMP will not regress cities of developed world to the 1970s or even in the Middle Ages, but rather before the agrarian era. It is noted that while the developed world will be more vulnerable, the least developed countries, could exhibit more resilience. Additionally, this paper considers the way societies and cities could demonstrate more resilience, framing the need for further research such as: technological adaptation; study and simulations of related scenarios; design of water-energy-food nexus for survival clusters; resilience measures for money, economy, communications, and trading. As we have a very small timeframe of data (less than 200 years) of the appearance and the effects of EMP, we have to study it, even if the wish is that we will never confront it. It seems unreasonable for our narcissistic and wonderful civilization to behave like ostrich hiding its’ head in the sand in order to be hidden by this threat.

Analysis of the electropulse processing effect on water absorption of cured synthetic thermosetting resins

The results of an experimental study of the efficiency of electric pulse treatment of cured synthetic thermosetting resins based on an assessment of the level of water absorption are presented. An experimentally proven positive effect of reducing the water absorption capacity of the cured samples of the studied resins after their irradiation with nanosecond electromagnetic pulses. regardless of the period of exposure of samples in water. A rational mode of irradiation of cured resins with nanosecond electromagnetic pulses has been established, during the implementation of which, for all the resins under study, the maximum decrease in the water absorption index is observed.

Generation of unipolar electromagnetic pulses in semiconductor nanocrystals

Generation of unipolar electromagnetic pulses in semiconductor nanocrystals

Experimental simulation of the generation of microwave radiation during the interaction of a lightning discharge with an aircraft

On a specialized testing installation — a high-voltage Marx generator, which allows the formation of a spark discharge up to 20 meters long, the process of the impact of lightning radio emission in the microwave range on an aircraft (AC) is simulated. A metal AC model made on a scale of 1:50 was placed in a 9 m long rod-plane spark gap. A positive voltage pulse was applied to the high-voltage electrode from the generator (front 100 μsec, duration 7500 μsec). The generated spark discharge passed through the AC model. It was found that when the spark channel passes through the body of the model, electromagnetic pulses of the microwave range with a duration of less than 500 psec and a rise time of less than 100 psec arise. The measurement of the resulting microwave pulses was carried out using special radio equipment in the subnanosecond range. High-speed photography of the discharge development, carried out synchronously with electromagnetic measurements, showed that microwave pulses (up to 10 GHz) arise at the stage of development of the spark discharge leader in the part of the “high-voltage electrode – insulated model” gap. Such pulses can be considered as a factor dangerous for various AC microwave radio systems, when the AC is struck by lightning, as well as for other objects, including power facilities, which contain equipment with microelectronics. Such microwave pulses can also occur during nearby lightning discharges (for example, in a lightning rod of a power substation), when a powerful streamer corona occurs on devices and wires of ultra-high voltage lines), and when a high-voltage spark discharge occurs when switching equipment (disconnectors, arresters) is triggered. In this case, disruptions are possible in the operation of control equipment (for example, relay protection devices) that contains microelectronics, as well as various communication means available at electric power facilities operating in the microwave range (above 1 GHz).

Influence of the Experimental Setup on Electromagnetic Pulses in the VHF Band at Relativistic High-Power Laser Facilities

We present experimental results for the controlled mitigation of the electromagnetic pulses (EMPs) produced in the interactions of a 1 PW high-power 30 fs Ti:Sa laser VEGA-3 with solid-density targets transparent to laser-forward-accelerated relativistic electrons. This study aims at the band of very high frequencies (VHFs), i.e., those in the hundreds of MHz, which comprise the fundamental cavity modes of the rectangular VEGA-3 vacuum chamber. We demonstrate mode suppression by a tailoring of the laser-produced space charge distribution.

Advanced Diagnostics of Electrons Escaping from Laser-Produced Plasma

This article provides an up-to-date overview of the problems associated with the detection of hot electrons escaping from laser-produced plasma and corresponding return current flowing from the ground to the target, which neutralises the positive charge occurring on the target due to the escaped electrons. In addition, the target holder system acts as an antenna emitting an electromagnetic pulse (EMP), which is powered by the return target. If the amount of positive charge generated on the target is equal to the amount of charge carried away from the plasma by the escaping electrons, the measurement of the return current makes it possible to determine this charge, and thus also the number of escaped electrons. Methods of return current detection in the mA–10 kA range is presented, and the corresponding charge is compared to the charge determined using calibrated magnetic electron energy analysers. The influence of grounded and insulated targets on the number of escaped electrons and EMP intensity is discussed. In addition to EMP detection, mapping of the electrical potential near the target is mentioned.

A novel framework to intercept GPS-denied, bomb-carrying, non-military, kamikaze drones: Towards protecting critical infrastructures

Protection of urban critical infrastructures (CIs) from GPS-denied, bomb-carrying kamikaze drones (G-B-KDs) is very challenging. Previous approaches based on drone jamming, spoofing, communication interruption and hijacking cannot be applied in the case under examination, since G-B-KDs are uncontrolled. On the other hand, drone capturing schemes and electromagnetic pulse (EMP) weapons seem to be effective. However, again, existing approaches present various limitations, while most of them do not examine the case of G-B-KDs. This paper, focuses on the aforementioned under-researched field, where the G-B-KD is confronted by two defensive drones. The first neutralizes and captures the kamikaze drone, while the second captures the bomb. Both defensive drones are equipped with a net-gun and an innovative algorithm, which, among others, estimates the locations of interception, using a real-world trajectory model. Additionally, one of the defensive drones is also equipped with an EMP weapon to damage the electronics equipment of the kamikaze drone and reduce the capturing time and the overall risk. Extensive simulated experiments and comparisons to state-of-art methods, reveal the advantages and limitations of the proposed approach. More specifically, compared to state-of-art, the proposed approach improves: (a) time to neutralize the target by at least 6.89%, (b) maximum number of missions by at least 1.27% and (c) total cost by at least 5.15%.

Electromagnetically induced gratings created by extremely short non-overlapping pulses of light in a three-level resonant medium

In a fixed spectral range, single- and half-cycle electromagnetic pulses have the shortest duration. Half-cycle pulses are promising tools for ultrafast control of quantum systems. Previously, the possibility of using a sequence of single- and half-cycle attosecond pulses to generate and ultrafast control light-induced population difference gratings has been demonstrated. However, such studies have been carried out using different approximations, such as the sudden perturbation theory and the two-level model for the resonant medium. In this paper, based on the numerical solution of constitutive equations for elements of the density matrix and wave equation it is shown that it is possible to generate and control population gratings in a three-level medium without using the approximation of sudden perturbations used in previous studies. It is shown that taking into account the additional level of the medium does not lead to a violation of the effect of generating such gratings. This extends the applicability of previous results.

The method for determining the safety factor of rock mass stability

The article is devoted to determining the safety factor of rock mass stability by measuring the intensity of electromagnetic pulses in the rock mass that are derived from natural stresses within the massif as well as additional applied loads imposed on it. The rock mass stability is evaluated according to the parameters of the electromagnetic pulses. The distinctiveness of this lies method in the preliminary determination of a frequency range corresponding to a specified depth within the mining massif, facilitating the calculation of the stability reserve coefficient. Explosive events resulting from the detonation of geological formations serve as external influences for instrumental measurements of the mass. The approach entails the measurement of electromagnetic pulses and the time required for these impulses to decay from post-explosion levels to the background electromagnetic pulses level. The stability reserve coefficient of the mass is subsequently determined through an equation accounting for the internal friction angle of the geological formations, the maximum electromagnetic pulses amplitude induced by the explosion, and the duration of decay until the background electromagnetic pulses level is reached.

Common‐mode current reduction in EMP coupling with the star‐quad cable having a reference conductor

AbstractThe coupling of electromagnetic pulse (EMP) with the star‐quad cable having reference conductor is analyzed by using the proposed model, which is based upon multi‐conductor transmission line theory. Expressions for common‐mode (CM) and differential‐mode (DM) currents are developed. Two cases are mainly discussed: the first case is the star‐quad cable with a central reference conductor, and the second case with the outside reference conductor. A rigorous comparison between these two cases shows that when the reference conductor is placed at the center, the magnitude of CM current is reduced dramatically, which is beneficial for electromagnetic compatibility (EMC). The CM current magnitude of the outside reference conductor is relatively very high due to the large CM current loop area, which is the least possible for the central reference conductor. There is no significant change in the DM current magnitude for both cases because the DM current has no direct dependence on the CM current loop area. A commercial software, FEKO, which utilizes the method of momentum (MoM), is used to compare the results of our proposed method, which are in good agreement.