Shielding System Research Articles

Structural Design of Hybrid Fillers in a Polymer Matrix for Advanced Electromagnetic Interference Shielding

The rapid development of modern advanced electronic systems has created a pressing need for multifunctional polymer composites that can withstand external adversities such as electromagnetic waves, flames, and mechanical stresses. Although these requirements can be satisfied by incorporating different types of fillers, high filler loadings often lead to issues such as poor processability and increased material costs. Herein, a multifunctional polyamide‐6 composite is introduced using a carbon‐fiber flame‐retardant hybrid filler to design a next‐generation electromagnetic interference (EMI) shielding system. Based on the synergistic effect of the functionality and structural arrangement of these fillers in the composite, the EMI shielding system demonstrates high EMI shielding performance, improved mechanical properties, and excellent flame retardancy despite the low filler content. The scalability and multifunctionality of the proposed system highlight its potential for use in next‐generation applications, such as electric vehicles, aerospace, and 5G/6G telecommunications.

Aloebarbadensis - Assisted MgBiO/MgCuBiO/MgBaBiO nanocomposites as effective gamma shielding novel materials

For the first of its kind, MgO/Bi2O3 (1:1) (MBO), MgO/CuO/Bi2O3 (1:1:1) (MCBO) and MgO/BaO/Bi2O3 (1:1:1) (MBBO) binary/ternary nanocomposites (NCs) were synthesized by Aloe barbadensis (Aloe vera) mediated solution combustion method. The as-formed NCs are subjected to calcination for 3 h at 600oC.The Mg-based NCs acquired are subjected to various analytical characterization methodologies, including PXRD (Powder X-ray Diffraction), SEM (Scanning Electron Microscopy), EDS (Energy Dispersive X-ray Spectroscopy), FTIR (Fourier Transform Infrared Spectroscopy), and Ultraviolet–Visible Spectroscopy (UV–Vis). The Bragg reflections confirm the formation of monoclinic phase BaO, Bi2O3, cubic MgO and tetragonal CuO nanoparticles. The surface morphology of MBO, MCBO and MBBO NCs consists of irregular sized, leafy and burrow like structured agglomerated NPs with hollows and voids/pores. The Eg (direct energy band gap) determined from W-H (Wood and Tauc's) plot was found to be 3.09, 3.19 and 3.12 eV for MBO, MCBO and MBBO NCs respectively. The evaluation of gamma radiation shielding properties was conducted using a NaI (Tl) detector connected to a multi-channel analyzer. Shielding parameters of MBO, MCBO and MBBO, such as μ/ρ (mass attenuation coefficient), λ (mean free path), HVL (half-value layer), TVL (tenth-value layer) are measured. Among the as-synthesized Mg-based NCs, MBO exhibits better shielding properties compared to MCBO and MBBO. Thus, the procured Mg-based NCs are suitable for applications where weight reduction is critical, such as aerospace or portable radiation shielding systems.

Radiation Exposure During Invasive Cardiovascular Procedures: Portable Shielding System Versus Standard Lead Aprons.

Introduction Significant progress in the field of interventional cardiology has led to a rise in percutaneous procedures and an increase in the risk of radiation exposure at the workplace. Staff health has been put at risk due to the limitations of conventional radiation protective techniques. Innovative methods, such as RAMPART, have promising prospects for enhancing radiation safety. The purpose of this study was to evaluate RAMPART's effectiveness and practicality in comparison to conventional protective techniques with a lead apron and shield (LAS) during cardiac interventional procedures. Method One hundred elective cardiac procedures were enrolled in this prospective single-center research study. Two groups were formed from the participants: standard protection (group A) and RAMPAT system (group B). Real-time dosimeters were used to track the radiation dosage, dosage reduction factor, dosage reduction percentage, and likelihood of exceeding the limit, which were included in the data. Proceduralists were urged to use different strategies to reduce exposure. The study was approved by an ethical committee and ran from June 2023 to August 2023. Results When comparing the RAMPART group to the conventional protection group, neck-level radiation exposure was considerably lower for all workers. There were no notable variations in the exposure of the waist. The RAMPART group was shown to be superior in minimizing radiation exposure, as evidenced by dose reduction metrics. The groups had comparable procedural characteristics. Conclusion Compared to conventional LAS, the RAMPART system dramatically reduces radiation exposure to the entire body.

To the problem of the shielding systems efficiency in constructions of extra-high voltage electrical apparatus

In the article, the authors proposed a method for estimating the electric load parameters to calculate the distribution of the electric field strength of the solid insulating structure of gas-filled high-voltage devices with axial symmetry. This structure consists of a support and insulating busbar filled with SF6 gas as an internal insulating medium. This technique allows to evaluate the parameters of the electrical load (voltage and field strength) depen-ding on the design features of the device and the shielding system used to equalize the electric field. The proposed methodology allows to evaluate the effectiveness of the influence of design parameters of the protection system for gas-filled high-voltage equipment (instrument transformers, arresters, surge arresters, etc.) when designing and improving individual design solutions. The calculation results are in good agreement with the data of experimental studies and statistical information obtained as a result of monitoring the operation of insulating structures, taking into account actual operating conditions and the influence of external factors. The implementation of this technique allows us to take into account the influence of external factors and operational characteristics inherent in instrument transformers and surge suppressors. In the proposed methodology, as an example, we consider a supporting insulating coating that is in operation under the most unfavorable conditions, such as external pollution, moisture and their combination, overvoltage of various origins, etc. The theoretical conclusions are confirmed by the results of calculations using the example of the support-insulating cover of the surge suppressor of the OПН-500 series. A more accurate determination of the effectiveness of the proposed methodology for predicting the field strength distribution parameters under the influence of a shielding system can be achieved by conducting an additional series of calculations and experimental tests of specific insulating structures. Thus, it was concluded that the obtained results can be used to evaluate the external insulation characteristics of both surge suppressors and gas-filled instrument transformers, as well as similar high-voltage equipment of switchgears and transformer substations in conditions of ultra- and transformer substations ultra-high voltages

An Optimal Radiation Shield Design of a Small Modular Nuclear Power Reactor by Genetic Algorithm

One of the critical concerns in developing small modular nuclear reactors (SMRs) is employing efficient radiation shielding consistent with the design and implementation requirements. Besides observing the radiation shielding requirements, the design process entails developing compact, lightweight shielding as well as ensuring the safety of the staff and radiation-sensitive equipment around the reactor under different operating conditions. Conventional methods of radiation shielding design are based on experiments conducted. Therefore, the resultant design involves trial and error, rarely achieving an optimal, effective, and efficient design. In this study, a multi-objective method based on the genetic algorithm coupled with the MNCP calculation code has been used to enhance the radiation shielding system of a SMR. Using this method, the thickness of different shielding layers has been optimized to minimize the total dose (neutrons and gamma) at the output, the weight, and the overall volume of the shielding. To assess and compare the method used to an implemented conventional method, a sample design of the MRX nuclear power reactor is considered. Using the optimization technique, the radiation shielding of the reactor has been redesigned and compared with the original design. This paper discusses the existing deficiencies in the initial design of the primary shield of the reactor as a design implemented based on conventional methods. Similar to the original design, the main materials considered for radiation shielding in consecutive layers were water and steel, and the final layer contained lead. The thickness of the different layers and their arrangements have been optimized to assess the upgraded method. The calculations indicate that the overall thickness of the proposed shielding is suggested as 93.8 cm compared to 140 cm to obtain the total dose of neutrons and gammas, which is suggested as less than 10 µSv/h. The results imply a 38.56% reduction in volume and a 17.24% reduction in weight of the radiation shielding compared to the reference reactor design.

Analysis of the features of the shielding system of polymer insulation structures of high voltage electrical equipment

In the article, the authors analysed the existing shielding systems of insulating structures of high-voltage devices together with electrodes under high potential. At the same time, the possibilities of using toroidal screens of various designs and the conditions of their installation in gas-filled equipment structures (gas-filled current and voltage measuring transformers, arresters, etc.) using polymer insulating materials are considered. Based on the analysis of literary sources, the most effective method of estimating the electric load parameters for determining the electric field strength distribution along the continuous insulating structure of gas-filled high-voltage devices with axial symmetry is proposed. This design is a support-insulating shell filled with SF6 as an internal insulating medium. Methodical materials are recommended that allow you to estimate the electrical load parameters (voltage and field strength) depending on the design features of the device and the shielding system used to level the electric field. Based on them, it is possible to evaluate the effectiveness of the calculation coefficients of the shielding system of gas-filled high-voltage equipment in the design process and during the improvement of individual design solutions. The results of the analytical evaluation by such methods are in good agreement with the data of experimental studies and statistical information obtained as a result of monitoring the work of insulating structures, taking into account real operating conditions and the influence of external factors. The introduction of the obtained materials allows you to take into account the influence of external factors and operational characteristics inherent in measuring transformers and overvoltage limiters. To explain the results of the analysis of methodical materials carried out in the article, as an example, the results of calculations of the support-insulation shell of the gas-filled current transformer of the TOG series, which was the most affected during operation, are given. in adverse conditions, given under such conditions as external pollution, humidity and their combination, as well as under conditions of overvoltage of various origins, etc. On the basis of the presented materials, it is possible to more accurately determine the effectiveness of various screenings. system, as well as how to predict the field strength distribution parameters under the influence of the shielding system, taking into account its design features. In addition, on the basis of the conclusions formed in the work, it is possible to plan and conduct an additional series of calculations and experimental tests taking into account the features of specific structures. Thus, the obtained results can be used to evaluate the external insulation parameters of both gas-filled measuring transformers and similar high-voltage equipment of distribution devices and transformer substations.

Radioassay of the materials for AMoRE-II experiment

The AMoRE-II experiment will search for the 0νββ decay of 100Mo nuclei using molybdate crystal scintillators, operating at milli-Kelvin (mK) temperatures, with a total of 80 kg of 100Mo. The background goal for the experiment is 10–4 counts/keV/kg/year in the region of interest around the 0νββ decay Q-value of 3,034 keV. To achieve this level, the rate of background signals arising from emissions produced by decays of radioactive impurities in the detector and shielding materials must be strictly controlled. To do this, concentrations of such impurities are measured and are controlled through materials selection and purification. In this paper, we describe the design and the construction materials used to build the AMoRE-II detector and shielding system, including active and passive shielding, the cryostat, and the detector holders and instrumentation, and we report on measurements of radioactive impurities within candidate and selected materials.

Exploring the thermal shielding performance by coupling phase change material to liquid cooling plate

To enhance the thermal shielding performance of high-temperature heat source target, an evolved cold shield system coupling phase change material (PCM) and liquid cooling plate with serpentine flow channel is developed. The thermal shielding effectiveness of the proposed system is illustrated by comparing the duration maintained at a lower temperature on the cold surface, and the temperature uniformity of the cold surface is analyzed to describe the role of PCM in the thermal shielding performance. The influences of the operating parameters of the liquid cooling plate and PCM physical parameters on the thermal shielding performance of the heat source targets are investigated. The results indicate that coupling PCM to a liquid cooling plate can effectively improve the thermal shielding performance. Increasing the heat power of the heat source target from 190 W to 231 W will lessen the advantage time from 3090 s to 1980 s for the coupled system. The advantage time is shortened by 1500 s as increasing the liquid volume flow rate from 0.26 L/min to 1.30 L/min. Lifting the starting temperature of the coolant from 15 °C to 25 °C prolongs the advantage time from 2130 s to 3090 s. The advantage time is improved by 660 s as increasing the PCM phase transition temperature from 26 °C to 30 °C, and increasing the PCM covering thickness from 8 mm to 10 mm extends the advantage time from 1830 s to 3090 s. Meanwhile, the temperature equalization of the cold surface for the coupled system is better than the single liquid cooling. These results indicate that the proposed coupled system has potential applications in improving thermal shielding performance as well as heat flow control, thermal insulation, and other areas of heat regulation.

The Effect of a Ferromagnetic Steel Enclosure on Magnetic Shielding Systems: Analysis, Modeling, and Experimental Validation

The Effect of a Ferromagnetic Steel Enclosure on Magnetic Shielding Systems: Analysis, Modeling, and Experimental Validation

Material Research for Hypersonic Travel

The goal of travelling faster than five times the speed ofsound, or hypersonic travel, has enormous potential to transform global transportation, defence capabilities, and space access. However, materials and structures face severe obstacles because to harsh aerothermal conditions inherent in high Mach number trajectories. This work focuses on new approaches to do research for ceramics, composites, and refractory alloys that are essential for building hypersonic vehicles. Essential design concepts for primary structures, heat shielding, and propulsion systems are covered, highlighting the critical role that theory and computation play in comprehending the links between structure, property, and processing. The remarkable high-temperature capabilities, stiffness, strength, and corrosion resistance of ceramic materials are highlighted in the study as reasons for theirincreasing importance in aircraft applications. Based on their distinct features, titanium alloys, nickel aluminides, metal- matrix composites, carbon-carbon, and ceramic-matrix composites stand out as top choices for a high temperature. In pursuit of lightweight, high- performance materials for hypersonic travel, this paper summarises ongoing researchefforts, evaluates the state of the art, offers insights into technological hurdles, and identifies areas that require future improvement. To explore the complex field of hypersonicmaterials design and selection in this research, this paper hope to shed light on the critical role that materials science plays in pushing the boundaries of aerospace technology by investigating the special difficulties presented by hypersonic flight as well as the characteristics and potential of various material classes.

Conduction cooled cryostat for small-scale superconducting radio frequency accelerator applications

Fermilab’s Illinois Accelerator Research Center (IARC) is designing small-scale, ∼10 MeV prototype conduction cooled superconducting accelerators for projects ranging from medical device sterilization to road pavement modification. These accelerators are built using high-Q Nb3Sn coated superconducting radio-frequency cavities. The cryostat design for one such prototype being developed for the U.S. Army Engineer Research Development Center (ERDC) will be described. Cryostats for such conduction cooled accelerators require stringent control of thermal losses since the available power from cryocoolers is restricted to a few watts. The present state of the vacuum vessel, conduction cooling system, thermal shield, cavity support, and other ancillary system designs will be described as well as presentation of thermal and structural simulations. Hopefully the work described in this paper will lead to the engineering construction of a cryostat which will accelerate an electron beam to high energy, ∼10 MeV, with extremely low thermal losses.

Analysis and measurement of magnetic noise in multilayer magnetic shielding system combined with mu-metal and ferrite for atomic sensors

The multilayer magnetic shielding system is widely used in atomic sensors. However, for miniaturized atomic sensors with volume limitations, such as spin-exchange relaxation-free (SERF) gyroscopes, the remaining environmental magnetic interference and mu-metal magnetic noise will affect the sensitivity of atomic sensors. In this study, we establish a comprehensive magnetic noise calculation model for the magnetic shielding system of a SERF gyroscope, which considers the influence of the environmental magnetic noise on the magnetic shielding and the coupling effect between different layers. For suppressing magnetic noise of the magnetic shielding system, the property of different ferrites was measured and compared, then the particle swarm optimization is applied to design the magnetic shielding structure. Finally, the experimental device is established for measuring performances of the magnetic shielding system per and post optimization. By comparison, radial and axial magnetic noise post optimization are decreased by 37% and 22%, respectively.

Conformal ultra‐miniaturized frequency selective surface for medical shielding applications

SummaryThis article presents a novel wearable frequency selective surface (FSS) for shielding the communication link of implantable devices with the external environment. The proposed shield blocks a dual‐band frequency operating at 404 MHz and 2.45 GHz in the medical implant communication service (MICS) and industrial, scientific, and medical (ISM) bands. The two distinct stop bands provide a high‐frequency band ratio of 6.02 in an ultra‐miniaturized physical form factor of 0.024λo × 0.024λo, with at least 76.96% miniaturization when compared to the existing art. Each of the unit cells is imprinted on a conformal 50 μm polyester substrate in a symmetrical configuration. The polyester adheres with jean to realize its compatibility with wearable applications. The designed shield system offers a low profile of only 0.00146λo. By suppressing the grating lobe, the proposed shield achieves a high angular stability of 80° and polarization insensitivity of 90° in both transverse electric (TE) and transverse magnetic (TM) modes. The FSS is fabricated and measured results validate its performance. To evaluate the physical insight, an equivalent circuit model (ECM) analysis is done. To ensure durability, the proposed shield system is tested with Amitech SDR04.

Magnetic Flux Sensor Based on Spiking Neurons with Josephson Junctions.

Josephson junctions (JJs) are superconductor-based devices used to build highly sensitive magnetic flux sensors called superconducting quantum interference devices (SQUIDs). These sensors may vary in design, being the radio frequency (RF) SQUID, direct current (DC) SQUID, and hybrid, such as D-SQUID. In addition, recently many of JJ's applications were found in spiking models of neurons exhibiting nearly biological behavior. In this study, we propose and investigate a new circuit model of a sensory neuron based on DC SQUID as part of the circuit. The dependence of the dynamics of the designed model on the external magnetic flux is demonstrated. The design of the circuit and derivation of the corresponding differential equations that describe the dynamics of the system are given. Numerical simulation is used for experimental evaluation. The experimental results confirm the applicability and good performance of the proposed magnetic-flux-sensitive neuron concept: the considered device can encode the magnetic flux in the form of neuronal dynamics with the linear section. Furthermore, some complex behavior was discovered in the model, namely the intermittent chaotic spiking and plateau bursting. The proposed design can be efficiently applied to developing the interfaces between circuitry and spiking neural networks. However, it should be noted that the proposed neuron design shares the main limitation of all the superconductor-based technologies, i.e., the need for a cryogenic and shielding system.

Structural Design for EMI Shielding: From Underlying Mechanisms to Common Pitfalls.

Modern human civilization deeply relies on the rapid advancement of cutting-edge electronic systems that have revolutionized communication, education, aviation, and entertainment. However, the electromagnetic interference (EMI) generated by digital systems poses a significant threat to the society, potentially leading to a future crisis. While numerous efforts are made to develop nanotechnological shielding systems to mitigate the detrimental effects of EMI, there is limited focus on creating absorption-dominant shielding solutions. Achieving absorption-dominant EMI shields requires careful structural design engineering, starting from the smallest components and considering the most effective electromagnetic wave attenuating factors. This review offers a comprehensive overview of shielding structures, emphasizing the critical elements of absorption-dominant shielding design, shielding mechanisms, limitations of both traditional and nanotechnological EMI shields, and common misconceptions about the foundational principles of EMI shielding science. This systematic review serves as a scientific guide for designing shielding structures that prioritize absorption, highlighting an often-overlooked aspect of shielding science.

Theoretical Analysis of a Magnetic Shielding System Combining Active and Passive Modes.

Considering the magnetic shielding requirements of both geomagnetic field and 50 Hz power-line frequency in the complex working conditions of the power grid, an electromagnetic shielding system combining active and passive modes is proposed in this article. A three-dimensional Helmholtz coil with a magnetic shielding barrel nested inside is established by the COMSOL simulation tool, and the magnetic shielding efficiency of the system is analyzed. Comparing different materials, the simulation results indicate that permalloy alloy exhibits better shielding performance than pure iron and nickel materials. Additionally, the overall shielding efficiency of the shielding barrel increases linearly with the number of multiple layers. Under the combined active and passive electromagnetic shielding conditions, the system achieves a shielding efficiency of SE = 113.98 dB, demonstrating excellent performance in shielding both AC and DC interference magnetic fields. This study provides theoretical guidance for the construction of magnetic shielding systems in electromagnetic interference environment.

3D interconnected graphene nanoplatelets and nickel ferrite based silicone rubber foams for effective electromagnetic interference shielding and thermal insulation performance

In the present study, porous composite foams made of silicon rubber (SR), graphene nanoplatelets (GnP), and nickel ferrite (NiFe2O4) nanoparticles were developed using the salt template approach. SR act as a 3D porous network, the conductive channel provided by graphene nanoplatelets and the magnetic and dielectric loss provided by the NiFe2O4 and the composite foam as a whole showed absorption-dominated EMI shielding due to synergism between GnP and NiFe2O4. Without NiFe2O4, the total EMI SE is 23 dB, while different NiFe2O4 weight percentages (0%, 3%, 6%, & 9%) increase the SET up to 36.7 dB. The thermal conductivity of this prepared sample is found to be 0.0313 Wm−1K−1 for 9 wt% filler content of NiFe2O4. It shows a moderately low value as compared to existing polymer composites. The resulting SR/GnP@NiFe2O4 composite foams, which are lightweight, strong, and multifunctional, have straightforward synthesis procedures and have a myriad of possible uses for EMI shielding systems and thermal insulations in the disciplines of aerospace, military engineering, electrical engineering and electronics.

Synthesis of the Spatial Arrangement of Magnetic Field Sensors for Active Magnetic Field Shielding Systems of Overhead Power Lines

The purpose of the work is to develop a synthesis method for the spatial and angular arrangement of magnetic field sensors in order to ensure maximum efficiency of a robust system for active shielding of the magnetic field generated by overhead power lines, and to reduce the sensitivity of the synthesized system to initial uncertainties in changes in the level of the initial magnetic field, as well as system parameters while working. To achieve this goal, the spatial location coordinates and angular position of all magnetic field sensors, controller parameters, and gain vector for the compensating windings are determined. A synthesis of the spatial location and angular position of magnetic field sensors is created to solve a minimax vector optimization problem in which the vector objective function is calculated based on the Biot-Savart’s law. Solution of the minimax vector optimization problem, calculated on the basis of optimization algorithms for a multi-swarm of particles from Pareto-optimal solutions, taking into account the parameters of binary relations. Significant results obtained on the basis of the developed synthesis method are the effectiveness of a robust active shielding system for magnetic fields generated, as a consequence, by power lines with a synthesized spatial arrangement and angular position of magnetic field sensors obtained in the process of theoretical and experimental research. The significance of the results lies in the fact that practical recommendations are given for the reasonable choice of spatial location and angular position of magnetic field sensors, the spatial arrangement of shielding windings of a robust magnetic field shielding system for various characteristics of power lines.

Research on extremely weak remanence measurement system

To accurately obtain the extremely weak magnetic field information of the test piece, this article first introduces the basic principles of the extremely weak residual magnetic field measurement technology. Then, an ultra-high precision magnetic shielding system has been developed, which is made of high permeability materials and equipped with a demagnetization coil system, and it can regularly eliminate the inductance of the entire shielding system. The effective shielding inner diameter of the magnetic shielding system is 0.8 m, the length is 1.6 m, and the magnetic field resolution is 0.0015 nT. This system can provide strong support for the measurement of extremely weak magnetic fields in materials and biomedical magnetic research.

Method for design of two-level system of active shielding of power frequency magnetic field based on a quasi-static model

Aim. Development of method for design a two-level active shielding system for an industrial frequency magnetic field based on a quasi-static model of a magnetic field generated by power line wires and compensating windings of an active shielding system, including coarse open and precise closed control. Methodology. At the first level rough control of the magnetic field in open-loop form is carried out based on a quasi-static model of a magnetic field generated by power line wires and compensating windings of an active shielding system. This design calculated based on the finite element calculations system COMSOL Multiphysics. At the second level, a stabilizing accurate control of the magnetic field is implemented in the form of a dynamic closed system containing, in addition plant, also power amplifiers and measuring devices of the system. This design calculated based on the calculations system MATLAB. Results. The results of theoretical and experimental studies of optimal two-level active shielding system of magnetic field in residential building from power transmission line with a «Barrel» type arrangement of wires by means of active canceling with single compensating winding are presented. Originality. For the first time, the method for design a two-level active shielding system for an power frequency magnetic field based on a quasi-static model of a magnetic field generated by power line wires and compensating windings of an active shielding system, including coarse open and precise closed control is developed. Practical value. It is shown the possibility to reduce the level of magnetic field induction in residential building from power transmission line with a «Barrel» type arrangement of wires by means of active canceling with single compensating winding with initial induction of 3.5 µT to a safe level for the population adopted in Europe with an induction of 0.5 µT.