Magnetic Coil Research Articles

Gap Self-Sensing Method for Maglev System Using Partial Electromagnet Coil

The use of dedicated sensor to measure levitation gap in maglev system leads to the problems of large volume, inconvenient installation and high cost. In this article, a gap self-sensing method using partial electromagnet coil is proposed to solve these problems. The entire electromagnet coil provides levitation force, while a small part of the electromagnet coil (the subcoil) on the side facing the levitated object is injected with high frequency excitation for gap self-sensing. The theoretical derivation shows the effects of levitation gap on the impedance of the subcoil. The frequency of the injected excitation and the structure of the subcoil are determined with finite element analysis for high sensitivity. The crosstalk between the gap self-sensing system and the levitation system is suppressed by the designed signal processing based on series resonance. The prototype in this article can cover a gap measurement range of 0–20 mm for maglev ball, with a nonlinearity error of 0.2% and a measurement accuracy of 0.2 mm. The closed-loop feedback control experiment shows that the performances of the proposed gap self-sensing system meet the control requirements.

Reversible Optical Isolators and Quasi-Circulators Using a Magneto-Optical Fabry–Pérot Cavity

Nonreciprocal optical devices are essential for laser protection, modern optical communication and quantum information processing by enforcing one-way light propagation. The conventional Faraday magneto-optical nonreciprocal devices rely on a strong magnetic field, which is provided by a permanent magnet. As a result, the isolation direction of such devices is fixed and severely restricts their applications in quantum networks. In this work, we experimentally demonstrate the simultaneous one-way transmission and unidirectional reflection by using a magneto-optical Fabry–Pérot cavity and a magnetic field strength of 50 mT. An optical isolator and a three-port quasi-circulator are realized based on this nonreciprocal cavity system. The isolator achieves an isolation ratio of up to 22 dB and an averaged insertion loss down to 0.97 dB. The quasi-circulator is realized with a fidelity exceeding 99% and an overall survival probability of 89.9%, corresponding to an insertion loss of ∼0.46 dB. The magnetic field is provided by an electromagnetic coil, thereby allowing for reversing the light circulating path. The reversible quasi-circulator paves the way for building reconfigurable quantum networks.

A numerical study on homogeneity and central field with axial spacing between DP coils of HTS magnet at 65 K

A numerical study is performed with COMSOL multi-physics, to analyze the effect of axial spacing between double pancake (DP) coils on central magnetic field and field homogeneity of High temperature Superconducting (HTS) magnet. The magnet is wound in the form of DP coils having, inner winding diameter as 100 mm and is operated at 65 K. The field homogeneity is calculated over a Diameter of Spherical Volume (DSV) of 40 mm for the entire study. The analysis is carried out by considering a constant length of HTS tape of 750 m and varying the number of DP coils from 4 to 14. The number of turns in all the DP coil is equal for a given set of DP coils to maintain the length of HTS tape to be constant. The coil separation within DP coils is of constant gap from 0.5 to 2 mm, while the axial spacing between the DP coils is varied from 0 to 50 mm for all the set of DP coils. The optimum gap between DP coils was evaluated using Exhaustive search optimization techniques and decreased with the number of DP coils. The best field homogeneity of 662.5 ppm was achieved with 14 DP coils having gDP=20.3 mm and gSP=2 mm for the chosen solenoid configuration.

Field recordings of transcranial magnetic stimulation in human brain postmortem models.

The ability of repetitive transcranial magnetic stimulation (rTMS) to deliver a magnetic field (MF) in deep brain targets is debated and poorly documented. To quantify the decay of MF in the human brain. Magnetic field was generated by single pulses of TMS delivered at maximum intensity using a flat or angulated coil. Magnetic field was recorded by a 3D-magnetic probe. Decay was measured in the air using both coils and in the head of 10 postmortem human heads with the flat coil being positioned tangential to the scalp. Magnetic field decay was interpreted as a function of distance to the coil for 6 potential brain targets of noninvasive brain stimulation: the primary motor cortex (M1, mean depth: 28.5 mm), dorsolateral prefrontal cortex (DLPFC: 28 mm), secondary somatosensory cortex (S2: 35.5 mm), posterior and anterior insulae (PI: 38.5 mm; AI: 43.5 mm), and midcingulate cortex (MCC: 57.5 mm). In air, the maximal MF intensities at coil center were 0.88 and 0.77 T for the flat and angulated coils, respectively. The maximal intracranial MF intensity in the cadaver model was 0.34 T, with a ∼50% decay at 15 mm and a ∼75% MF decay at 30 mm. The decay of the MF in air was similar for the flat coil and significantly less attenuated with the angulated coil (a ∼50% decay at 20 mm and a ∼75% MF decay at 45 mm). Transcranial magnetic stimulation coil MFs decay in brain structures similarly as in air, attenuation with distance being significantly lower with angulated coils. Reaching brain targets deeper than 20 mm such as the insula or Antérior Cingulate Cortex seems feasible only when using angulated coils. The abacus of MF attenuation provided here can be used to adjust modalities of deep brain stimulation with rTMS in future research protocols.

A Untethered Magnetic Micro-Robot for Local Therapeutic Delivery for Neurosurgical Oncology

INTRODUCTION: Microrobots designed for biomedical applications have garnered significant research interest, offering advantages in drug delivery, microsurgery, and biopsies. Magnetic fields enabled by electromagnetic coils permit untethered nonlinear movement of these tiny robots within the brain on the surface, the cerebrospinal fluid, and parenchyma. Microdrillers (either individually or in swarms) are a promising tool for microsurgery, capable of drilling through viscoelastic media (brain tissue). However, challenges remain in scaling down the robot size and exploring diverse applications. METHODS: Parallelizable (batch) microfabrication involved 3D printing via two-photon lithography. The pH-sensitive hydrogel was synthesized through UV-initiated radical polymerization mixed with a tracer (fluorescein sodium salt). Imaging via photon-counting CT was performed for microbot tracking in preclinical models including hydrogel phantoms, large animal cadaveric fresh brain tissue, and human cadaveric tissue. RESULTS: Microbot speeds in various tissues were characterized with speeds up to 800 um/sec over magnetic field amplitudes of 5 to 55 mT while performing complex nonlinear trajectories via open-loop surgeon control via surgeon. Targeted hydrogel delivery of fluorescein label/nanoparticle drug over a pH range of 6.2 (tumor tissue) and 7.8 (normal tissue) over a time interval of 50 s is demonstrated as proof of concept with a rate of 2.4 times faster in acidic conditions. Lastly, we show state-of-the-art micromillmetric resolution for real time imaging via photon-counting spectral CT for implementation of closed loop control. CONCLUSIONS: A novel minimally invasive microrobotic platform technology capable of targeted local drug delivery in brain parenchyma is demonstrated.

Model Predictive Control of Magnetic Helical Swimmers in Two-Dimensional Plane

Magnetic micro/mini-swimmers have a great potential application in biomedical research and have gained broad attention. Recent research studies focus on the automatic control methods of magnetic micro/mini-swimmers, such as artificial intelligence methods. However, their autonomous manipulation remains a challenge since they are subject to various disturbances from the external environment and model uncertainties. The current methods employ a status observer to estimate these disturbances and uncertainties. In this paper, we apply a data-driven technique that utilizes the nonlinear approximation ability of neural networks (NNs). To be specific, a flexible structure of NNs, Broad Learning System (BLS), is employed to model the input-output mapping relationship between the direction of the rotating magnetic field and the swimming direction of the helical miniature swimmer. Then, according to the dual-variable decoupling control, a levitation controller is formulated and a path following controller is proposed based on a planar three-degree-of-freedom model of magnetic helical swimmers, which is inspired by the model of wheeled mobile robots. Simulations and experiments are conducted to quantitatively validate the proposed control method using different planar paths. The experiment results show that the mean absolute error of the path following control is about 3 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\%$</tex-math> </inline-formula> of the body length which is less than 0.5 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$mm$</tex-math> </inline-formula> . Our proposed control method provides a preliminary study to alleviate the impact of disturbances and uncertainties on the control performance of magnetic micro/mini-swimmers. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —This paper is mainly motivated by the potential application of artificial intelligence methods in magnetic micro/mini-robot community, especially for the applications that reject disturbances and uncertainties. In practice, a path planner is employed to compute a pre-defined reference path that connects the start and the targeted locations. Then our control method is applied to the magnetic helical swimmer and it is guided to follow the reference path. Tackling external disturbances and model uncertainties is still challenging during the control progress. Neural network-based technique is an intuitive approach since their nonlinear modeling ability and generalization are suitable for estimating these disturbances and uncertainties. As for training the neural-network model, the training data about the angle parameters should be recorded by manual control of the helical swimmer. These angle parameters define the rotating axis of the uniform rotating magnetic field and the self-rotating axis of the magnetic helical swimmer. According to the planar motion model, the optimal controller is formulated using the feedback distance error and angle error, and the sum of the control signal and the prediction of the compensating model is used as the final control input. Our electromagnetic coil system features easy operation and configuration of cameras or other sensors. Simulations and experiments validate the performance of the neural network-based compensating method and the proposed optimal control method using magnetic micro/mini-swimmers.

A numerical simulation method for solving electromagnetic-mechanical coupling field

A new numerical simulation method based on the finite volume method has been proposed to address the challenges associated with the pseudo-oscillation phenomenon that occurs with an increased Péclet number, as well as determining an appropriate time step for electromagnetic-mechanical coupled physical field calculations. This method utilizes the concept of upwind from Computational Fluid Dynamics (CFD) to solve Maxwell's equations, a finite-volume method for discretizing the electromagnetic diffusion equations. Through computing typical electromagnetic field problems such as TEAM problem 9–1 and comparing the results to the literature, it has been confirmed that this method has sufficient computational accuracy to solve electromagnetic field numerical simulation problems containing moving conductors. Additionally, a three-dimensional simulation model of the electromagnetic coil gun has been established to verify the viability of the proposed method for solving magnetic field problems under the electromagnetic launch (EML) system. The study also examined the change in magnetic field strength and current density of the EML device during the launching process. The results lay the foundation for the technical application of this method.

High Speed Fighter UAV with Electric Coil Gun

The paper focus on "High-Speed Fighter Drone Using Electromagnetic Coil Gun and Dropping Mechanism" project represents a significant milestone in the realm of unmanned aerial vehicles (UAVs). This project aimed to design, develop, and demonstrate a cutting-edge high-speed fighter drone equipped with an electromagnetic coil gun and an advanced payload deployment mechanism. The primary objectives were to enhance drone maneuverability, achieve precision targeting capabilities, and enable efficient payload deployment, thus expanding the potential applications of UAV technology. This project involved an intricate blend of engineering, innovation, and technology integration. The drone's design and construction incorporated a lightweight yet durable frame, high-speed motors, and advanced flight control systems, ensuring exceptional agility and stability during flight. The electromagnetic coil gun, a pivotal component, was meticulously designed for precision targeting, delivering impressive accuracy and firing control. Moreover, the payload deployment mechanism, a vital feature of the system, was developed to ensure the precise and reliable delivery of payloads, expanding the drone's versatility across various domains, including defense, surveillance, and emergency response Throughout the project's lifecycle, rigorous testing, calibration, and data analysis were conducted to validate the drone's performance, accuracy of the electromagnetic coil gun, and efficiency of the payload deployment mechanism. The project yielded promising results, demonstrating the drone's exceptional flight performance, electromagnetic coil gun's precision targeting, and payload deployment's reliability. This project report provides a comprehensive overview of the project's objectives, methodologies, results, and significance. It explores the intricate system design, integration processes, testing procedures, and detailed analyses of outcomes. Furthermore, it discusses the challenges faced during development and the potential impact of this high- speed fighter drone in various industries. In conclusion, the "High-Speed Fighter Drone Using Electromagnetic Coil Gun and Dropping Mechanism" project represents a significant leap forward in UAV technology. Its successful realization opens up new possibilities for drone applications, promising advancements in precision targeting, payload deployment, and the overall versatility of UAVs in both civilian and military contexts

Use of nonlinear pulsed magnetic fields for spatial encoding in magnetic resonance imaging

This study examines the use of nonlinear magnetic field coils for spatial encoding in magnetic resonance imaging. Existing theories on imaging with such coils share a complex reconstruction process that originates from a suboptimal signal interpretation in the spatial-frequency domain (k-space). In this study, a new solution to this problem is proposed, namely a two-step reconstruction process, in which in the first step, the image signal is converted into a frequency spectrum, and in the second step, the spectrum, which represents the distorted image, is geometrically and intensity corrected to obtain an undistorted image. This theory has been verified by numerical simulations and experimentally using a straight wire as a coil model for an extremely nonlinear magnetic field. The results of this study facilitate the use of simple encoding coil designs that can feature low inductance, allowing for much faster switching times and higher magnetic field gradients.

Control of Self-Winding Microrobot Using an Electromagnetic Drive System: Integration of Movable Electromagnetic Coil and Permanent Magnet.

Achieving precise control over the motion position and attitude direction of magnetic microrobots remains a challenging task in the realm of microrobotics. To address this challenge, our research team has successfully implemented synchronized control of a microrobot's motion position and attitude direction through the integration of electromagnetic coils and permanent magnets. The whole drive system consists of two components. Firstly, a stepper motor propels the delta structure, altering the position of the end-mounted permanent magnet to induce microrobot movement. Secondly, a programmable DC power supply regulates the current strength in the electromagnetic coil, thereby manipulating the magnetic field direction at the end and influencing the permanent magnet's attitude, guiding the microrobot in attitude adjustments. The microrobot used for performance testing in this study was fabricated by blending E-dent400 photosensitive resin and NdFeB particles, employing a Single-Layer 4D Printing System Using Focused Light. To address the microrobot drive system's capabilities, experiments were conducted in a two-dimensional and three-dimensional track, simulating the morphology of human liver veins. The microrobot exhibited an average speed of 1.3 mm/s (movement error ± 0.5 mm). Experimental results validated the drive system's ability to achieve more precise control over the microrobot's movement position and attitude rotation. The outcomes of this study offer valuable insights for future electromagnetic drive designs and the application of microrobots in the medical field.

Magnetic field detection utilizing soft magnetic ribbons and a rectangular solenoid

An effective approach to high-sensitivity magnetic field detection under low-frequency excitation by soft magnetic ribbons and a rectangular solenoid is proposed and certificated. The solenoid wound by nonmagnetic copper wire is located at the geometric center region of the soft magnetic ribbons that act as the magnetic core. The proposed magnetic sensor utilizes the nonlinear magnetization of soft magnetic ribbons and the magneto-inductive effect and proximity effect of the solenoid, exhibiting significant impedance variation at a relatively low frequency. The impedance ratio and impedance sensitivity of the prototype reaches the maximum value of 5630% and 570% Oe−1 at 500 kHz, which is far superior to the conventional giant magneto-impedance (GMI) magnetic sensor and planar coil laminated GMI magnetic sensor. The investigation indicates the fabricated magnetic sensor with optimal dimension parameters can provide a sensitivity of 3329 mV Oe−1 at 500 kHz. More importantly, the proposed prototype is particularly suitable for micromachining, providing the possibility for manufacturing high-sensitivity micro-magnetic sensors.

Insertion Performance Study of an Inductive Weft Insertion System for Wide Weaving Machines

Wide weaving machines traditionally enhance the weaving width by increasing the shuttle’s initial velocity. However, this approach introduces challenges like pronounced equipment vibration, elevated noise levels, heightened energy consumption, and a reduced lifespan. Moreover, its efficacy in significantly widening fabric is constrained. Addressing these concerns, this paper proposes a wide-width warp insertion solution that involves driving the high-temperature superconducting shuttle to achieve high-speed horizontal flight through a traveling magnetic field. The inductive weft insertion system structure of wide weaving machines comprises an insertion guideway with an iron core and wound electromagnetic coils. The shuttle consists of a high-temperature superconducting block and a conductive plate, serving as the driving element. By establishing the equivalent circuit of the weft insertion guideway and the suspended shuttle, the calculation formula for the dynamic driving performance of the weft insertion guideway is obtained. Utilizing a transient 3D magnetic field simulation model, the impact of parameters like the current frequency, shuttle conductive plate thickness, and suspension gap on weft insertion performance is explored. Successful wide-width weft insertion motion is achieved by controlling coil input current parameters. Finally, an experimental platform is constructed to validate the correctness of the weft insertion system structure and simulation model through practical experiments.

Neutronics analysis of the ion cyclotron resonance heating antenna of the China Fusion Engineering Test Reactor

Ion cyclotron resonance heating (ICRH) is an important auxiliary heating method applied to the China Fusion Engineering Test Reactor, which can effectively heat the ions and electrons in plasma. Owing to the harsh nuclear environment, neutronic analyses are required to verify tritium self-sufficiency and neutron-shielding requirements. In this study, a neutronics analysis of the ICRH antenna was conducted using the COre and System integrated engine for Reactor Monte Carlo (cosRMC) code to estimate the neutron flux, radiation damage, nuclear heating, gas generation rate of key components, and tritium breeding ratio (TBR), providing data support for the subsequent optimization of the shielding design. In addition, the neutron flux of the coils around the antenna was calculated to prevent the entry of neutrons that damage the magnetic field coils through the gaps between the port plugs and antenna, and the shielding effects of the port-plug antenna on the surrounding components were analyzed. Finally, the results obtained using the cosRMC and MCNP codes were compared, which and presented good agreement, thus verifying the reliability of the neutronic analysis using the cosRMC code.

Machine Learning for the Design and the Simulation of Radiofrequency Magnetic Resonance Coils: Literature Review, Challenges, and Perspectives.

Radiofrequency (RF) coils for magnetic resonance imaging (MRI) applications serve to generate RF fields to excite the nuclei in the sample (transmit coil) and to pick up the RF signals emitted by the nuclei (receive coil). For the purpose of optimizing the image quality, the performance of RF coils has to be maximized. In particular, the transmit coil has to provide a homogeneous RF magnetic field, while the receive coil has to provide the highest signal-to-noise ratio (SNR). Thus, particular attention must be paid to the coil simulation and design phases, which can be performed with different computer simulation techniques. Being largely used in many sectors of engineering and sciences, machine learning (ML) is a promising method among the different emerging strategies for coil simulation and design. Starting from the applications of ML algorithms in MRI and a short description of the RF coil's performance parameters, this narrative review describes the applications of such techniques for the simulation and design of RF coils for MRI, by including deep learning (DL) and ML-based algorithms for solving electromagnetic problems.

Study of changes in the surface structure of tungsten irradiated by helium plasma

One of the important aspects is the interaction of plasma with the surface of a material, especially in the conditions of a fusion facility. The current work presents the preliminary results of the study of tungsten surface structure modification under helium plasma irradiation. A small-sized linear simulator KAZ-PSI with a plasma-beam setup was designed and assembled, where helium was used as a working gas. The main elements of the linear plasma simulator are an electron beam gun with a LaB6 cathode, a plasma-beam discharge chamber, an interaction chamber, a target device, and an electromagnetic system consisting of electromagnetic coils. It was revealed that under irradiation on the surface of the samples there is a relief with defective structure consisting of chaotically arranged ledges and pits of various shapes with average size (100‒600) nm and pore sizes (0.1‒1.5) μm with visible areas of flaking and sputtering. It was found that when the negative potential on the target is varied by –500V/–1000V/–1500V, the formation of dislocation with chaotic and cellular structure of tungsten with an average grain size of (1‒25) μm is observed; it was revealed that the total values of elastic and plastic components of deformation across the tungsten grain differ from each other by about 2.5 times.

Diagnostic Insights for Optimal Avanza/Xenia AC Performance

This study investigates the AC system of Avanza/Xenia vehicles through diagnostic procedures aimed at identifying potential issues and ensuring adherence to maintenance standards. The air conditioning (AC) system in vehicles plays a pivotal role in ensuring driver and passenger comfort, necessitating regular monitoring and maintenance. Utilizing measuring tools such as compressors and multimeters, the main components including the magnetic clutch and evaporator were assessed. Results indicate that measured values, including magnetic clutch coil resistance (3.9 ohms), magnetic clutch gap (0.5 mm), and blower system resistance (ranging from 0 to 2.6 ohms), fall within acceptable service limits outlined in the Avanza/Xenia manual. Consequently, no repair procedures were deemed necessary, affirming the normal condition and suitability for use of the AC system. This research fills a knowledge gap by providing a systematic diagnostic approach for evaluating vehicle AC systems, offering implications for maintenance practices in ensuring optimal performance and longevity. Highlights: Routine maintenance prolongs AC system lifespan. Accurate diagnosis prevents potential issues. Component inspection ensures system health. Keywords: PMCB, Vehicle Air Conditioning System, Maintenance, Repair, Troubleshooting

Vibration analysis of a rotor-bearing system using magneto-rheological elastomers

Magneto rheological materials are considered as a promising adaptive means of vibration control. This paper proposes a new configuration of smart bearings comprising magneto-rheological elastomer (MRE) layer inserted between the bearing pedestal and the foundation. This configuration provides a directional vibration controllability in both horizontal and vertical directions of a rotor-bearing system. The effect of using MRE layer on the vibration response and the resonant speeds of a rotor-bearing system is investigated. The finite element method is used to derive a dynamic model for the rotor-bearing system using shaft elements based on the Rayleigh beam theory and accounting for the gyroscopic effect and internal damping of the shaft. Simulation results reveal that the use of MRE materials in passive mode leads to downshifting of the first two resonant speeds and the attenuation of the steady state vibration response of the rotor bearing system in the horizontal and vertical directions at the resonance frequencies. When the MRE layer is subjected to a magnetic field generated by an electric current produced in the magnetic coil, the horizontal and vertical vibration responses are increased at the resonant speeds but decreased at other rotational speed ranges. Furthermore, the first two resonant speeds in the horizontal and vertical directions decrease further with the increase of the electric current.

Development of a new magnetic mirror device at the Korea Advanced Institute of Science and Technology

A new magnetic mirror machine named KAIMIR (KAIST mirror) has been designed and constructed at the Korea Advanced Institute of Science and Technology (KAIST) to study mirror plasma physics and simulate the boundary regions of magnetic fusion plasmas such as in a tokamak. The purpose of this paper is to introduce the characteristics and initial experimental results of KAIMIR. The cylindrical vacuum chamber has a length of 2.48 m and a diameter of 0.5 m and consists of three sub-chambers, namely the source, centre and expander chambers. A magnetic mirror configuration is achieved by electromagnetic coils with a maximum magnetic field strength of 0.4 T at the mirror nozzles and 0.1 T at the centre. The source plasma is generated by a plasma washer gun installed in the source chamber with a pulse forming network system. The typical discharge time is ~12 ms with a ~6 ms (1–7 ms) steady period. Initial results show that the on-axis electron density at the centre is 1019–20 m−3 and the electron temperature is 4–7 eV. Two parameters were varied in this initial phase, the source power and the mirror ratio, which is the ratio of highest to lowest magnetic field strength in the mirror-confined region. We observed that the increase of the electron density was mitigated for a source power above 0.2 MW. It was also found that the electron density increases almost linearly with the mirror ratio. Accordingly, the stored electron energy was also linearly proportional to the mirror ratio, similar to the scaling of the gas dynamic trap.

Effects of botulinum neurotoxin on regularity of head oscillations in cervical dystonia

Introduction: This study explores the effects of botulinum neurotoxin (BoNT) on the relationship between dystonia and tremor, specifically focusing on cervical dystonia (CD) and its connection to head tremor.Methods: Fourteen CD patients were recruited; eight (57%) with clinically observable head oscillations were included in further analysis. A high-resolution magnetic search coil system precisely measured head movements, addressing two questions: 1) BoNT’s effects on head movement amplitude, frequency, and regularity, and 2) BoNT’s influence on the relationship between head position and head oscillations. For the first question, temporal head position measurements of three patients were analyzed before and after BoNT injection. The second question examined the effects of BoNT injections on the dependence of the oscillations on the position of the head.Results: Three distinct trends were observed: shifts from regular to irregular oscillations, transitions from irregular to regular oscillations, and an absence of change. Poincaré analysis revealed that BoNT induced changes in regularity, aligning oscillations closer to a consistent “set point” of regularity. BoNT injections reduced head oscillation amplitude, particularly in head orientations linked to high-intensity pre-injection oscillations. Oscillation frequency decreased in most cases, and overall variance in the amplitude of head position decreased post-injection.Discussion: These findings illuminate the complexity of CD but also suggest therapeutic potential for BoNT. They show that co-existing mechanisms contribute to regular and irregular head oscillations in CD, which involve proprioception and central structures like the cerebellum and basal ganglia. These insights advocate for personalized treatment to optimize outcomes that is based on individual head oscillation characteristics.

Design and Development of Electromagnet Power Supply for Burst Mode Repetitive High Power Microwave Sources

Single frequency High-power microwave sources like Backward Wave Oscillator, Relativistic Magnetron etc., require a high magnetic field of about 1T to 4T for efficient operation. Single-shot HPM systems usually consist of pulsed magnetic systems. However, for repetitive HPM generation, a continuous magnetic field is required. To obtain a continuous high magnetic field in the required volume usually three solutions are worldwide preferred i.e., permanent magnet, DC electromagnet with cooling arrangements and superconductor-based magnetic coil. All these three systems are bulky, expensive and technologically demanding. In this paper, a novel power supply has been suggested that discharges a charged capacitor through a magnetic coil keeping the discharging current constant for a small period like hundreds of milliseconds to a second. An IGBT switch is used to discharge the capacitor1. The duty cycle of the IGBT switch is controlled using a current feedback signal from the hall sensor, thus keeping the current steady at a preset reference value. An experimental setup has been developed using a 300mF capacitor. A constant current up to 500A is achieved for 200mS. This system is scalable. For a longer duration of operation, more capacitor modules need to be added. Details of design, development and experimental results are presented in this paper.