Horizontal Electric Field Research Articles

Effects of the focus ring on the ion kinetics at the wafer edge in capacitively coupled plasma reactors

The fabrication process of modern microelectronic devices faces a significant challenge regarding the uniformity of wafer processing during plasma etching. Particularly, nonuniformity is prominent at the wafer edge due to varying electrical properties, leading to sheath bending and distorted ion trajectories. To address this issue, a wafer terminating structure known as a focus ring is employed to modify the sheath structure near the edge of the wafer and ensure uniform ion fluxes. However, the focus ring is subject to erosion caused by the plasma, making it crucial to minimize the ion energy bombarding the focus ring. In light of this, this paper investigates the impact of parameters such as the wafer-focus ring gap, focus ring height, and dielectric constant of the focus ring on the ion angle onto the wafer and the ion energy onto the focus ring. To conduct the analysis, a 2D3V particle-in-cell/Monte Carlo collision model is utilized. The study reveals the existence of horizontal electric fields with opposite directions at the wafer edge and the inner edge of the focus ring. Optimizing the ion angle onto the wafer edge can be achieved by adjusting the material and geometry of the focus ring. Furthermore, reducing the ion energy at the focus ring can be accomplished by increasing the height or decreasing the dielectric constant of the focus ring.

A compact printed hybrid‐mode antenna for dual‐band dual‐sense circular polarisation

AbstractA compact printed hybrid‐mode antenna for dual‐band dual‐sense circular polarisation (CP) has been proposed. To achieve dual‐band dual‐sense CP, a hybrid mode produced by an L‐shaped element and a loop element is used. In the lower frequency band, the left‐handed CP is radiated by a vertical electric field from the L‐shaped element and a horizontal electric field from the loop element. In the higher frequency band, the right‐handed CP is radiated by a horizontal electric field from the L‐shaped element and a vertical electric field from the loop element. Both the L‐shaped and the loop elements produce resonances in the lower and higher frequency bands. The operational principle for dual‐band dual‐sense CP is clarified using the simulated orthogonal components of the electric fields and the simulated electric current distributions. Parametric studies are discussed in the design procedure. The simulated and measured input reflection coefficient, axial ratio, absolute gain, and radiation pattern are presented. The measured bandwidths of −10dB‐input reflection coefficient with a 3dB‐axial ratio are 2.37–2.55 GHz (7.32%) in the lower frequency band and 3.38–3.70 GHz (9.04%) in the higher frequency band. The antenna size is 0.0741λ2.452 and 0.151λ3.52 (λ f is a wavelength at f GHz).

A dataset of field-aligned Poynting flux in the dayside polar cap of the northern hemisphere during 2014-2016

The transport of electromagnetic energy in the polar upper atmosphere and its spatial and temporal distribution are current hot issues and important topics for studying the polar upper atmospheric environment and space weather forecasting models. Researchers usually adopted the observations from low-altitude polar-orbiting satellites to estimate the magnitude and direction of electromagnetic energy. The continuous accumulation of electromagnetic energy data will be beneficial to the study on the transmission and variation characteristics of electromagnetic energy in the polar ionosphere in China. In this paper, we estimated the distribution of field-aligned Poynting flux, horizontal convection electric field and magnetic field perturbation in the dayside polar cap based on the plasma velocity and magnetic field data of DMSP F17 satellite in the northern hemisphere during 2014-2016. The initial DMSP F17 satellite data included in this dataset are of high quality. The estimation process is rigorous and reasonable, and the data records are complete. The dataset can provide important data support for the study on energy transport and dissipation in the ionosphere/thermosphere in the polar region.

Wide field electromagnetic method calculation in arbitrary orientation and its effectiveness analysis

The wide field electromagnetic method E_Ex observation method requires the horizontal electrical field source (AB) to be parallel to the measure station (MN), but the complex terrain conditions make it difficult to meet the AB parallel MN in field construction, and there is always an azimuthal difference α between them, which will bring a large calculation error and cause distortion of the interpretation parameters if the calculation method E_Ex continues to be used. In order to tackle this problem, we analyse and study the E_Ex method and derive the new calculation method of E_EMN for the wide field electromagnetic method along the MN (E_EMN). The method is based on the intrinsic relationship between the electric field components Ex, Ey and the azimuthal difference α and derives the expression for the electric field E_EMN along the MN direction, and then uses the E_EMN to calculate the wide field apparent resistivity. In this paper, we design a three-layer geoelectric model and calculate the azimuthal angle difference α = 0° and α = 15°wide field apparent resistivity parameters, respectively. The results show that the relative error between the calculated apparent resistivity and the theoretical value is less than 1%, which verifies the correctness and validity of the method. To further verify the accuracy of the method, experimental work on azimuthal difference α was carried out next to a known well in Sichuan. The results show that: firstly, when α is 1°, 3°, 5°, 10°, and 15°, respectively, the relative error of each frequency point increases with α increasing. Secondly, when α is 1°, 3°, 5°, 10°, and 15°, respectively, the relative error of each frequency point is less than 10% when the EMN method is used to calculate the wide field apparent resistivity value; thirdly, taking α = 15° as an example, single-station inversions are performed with Ex and EMN apparent resistivity parameters, in which the Ex inversion results are more different from the trend of the logging curve, while the EMN inversion results are relatively more consistent with the trend of the logging curve. The arbitrary orientation EMN calculation method proposed in this paper can effectively reduce the influence of α on the interpretation parameters and improve the accuracy of interpretation, and also greatly expand the applicability and flexibility of Ex wide field electromagnetic method in the observation of complex terrain areas, which has important theoretical research and practical production significance.

A New Approach to the Evaluation of the Lightning Horizontal Electric Field Over a Lossy Ground Based on the Time-Domain Cooray–Rubinstein Formula Fitted by Orthogonal Polynomials

The calculation of lightning return stroke electromagnetic field is the basis for evaluating transmission line lightning-induced voltages. The Cooray–Rubinstein formula in the time domain is widely used to evaluate the horizontal electric field of lightning return stroke on a lossy ground, but the evaluation of the formula requires high computation cost. Therefore, this study presents a new approach to evaluate the Cooray–Rubinstein formula based on orthogonal polynomial fitting. This method converts the complex convolution in the Cooray–Rubinstein formula into the sum of multiple simple convolutions by using an effective truncation scheme of Legendre orthogonal polynomial and the second Chebyshev orthogonal polynomial. The objective is to realize an efficient evaluation method to the horizontal electric field of the lightning return stroke. On the premise of ensuring the calculation accuracy, the effectiveness and correctness of the proposed method are verified through numerical experiments. Moreover, the application of the time-domain Cooray–Rubinstein formula based on two orthogonal polynomial fitting methods is discussed. Compared with the existing numerical methods for solving the Cooray–Rubinstein formula, the proposed method is easy to implement and efficient, which provides a new idea for evaluating the horizontal electric field of lightning return stroke above the lossy ground in the time domain.

Data-driven Radiative Magnetohydrodynamics Simulations with the MURaM Code

We present a method of conducting data-driven simulations of solar active regions and flux emergence with the MURaM radiative magnetohydrodynamics (MHD) code. The horizontal electric field that is derived from the full velocity and magnetic vectors is implemented at the photospheric (bottom) boundary to drive the induction equation. The energy equation accounts for thermal conduction along magnetic fields, optically thin radiative loss, and heating of coronal plasma by viscous and resistive dissipation, which allows for a realistic presentation of the thermodynamic properties of coronal plasma that are key to predicting the observational features of solar active regions and eruptions. To validate this method, the photospheric data from a comprehensive radiative MHD simulation of solar eruption (the ground truth) are used to drive a series of numerical experiments. The data-driven simulation reproduces the accumulation of free magnetic energy over the course of flux emergence in the ground truth with an error of 3%. The onset time is approximately 8 minutes delayed compared to the ground truth. However, a precursor-like signature can be identified at the correct onset time. The data-driven simulation captures key eruption-related emission features and plasma dynamics of the ground truth flare over a wide temperature span, from to . The evolution of the flare and coronal mass ejection as seen in synthetic extreme ultraviolet images is also reproduced with high fidelity. This method helps to understand the evolution of magnetic field in a more realistic coronal environment and to link the magnetic structures to observable diagnostics.

A 3-D phase field study of dielectric droplet impact under a horizontal electric field

A 3-D diffuse interface model has been developed to simulate impact of a dielectric droplet under the influence of a horizontal electric field. The Cahn-Hilliard equation, coupled with the Navier-Stokes equations, is employed to track liquid-gas interface. The model is discretized utilizing the finite difference method on a half staggered grid and solved using the projection method with the aid of OpenMP. Mesh independence test was also performed to choose an appropriate grid size. After validating the model, extensive simulations were conducted. The paper takes into account various factors influencing drop impact dynamics under real conditions, such as contact angle and impacting velocity. Numerical results show that for a moderate electric field, the electric force stretches a droplet in the direction of the applied electric field, and that a horizontal electric field can be useful to suppress splashing by reducing the rising angle made by the lamella with the substrate.

Coastal Effect in the Horizontal Components of the Electric Field

The results of experimental studies of electric field disturbances generated by sources of an ionosphericorigin in the coastal zones of the White and Barents seas are presented. The data recording was performedby geophysical stations GI-MTS-1. The horizontal electric field was recorded by telluric lines ~50 mlong. The Ex component was set orthogonally to the coastline in the direction from the shore, and the Еycomponent was directed along the coastline. In the coastal strip of the sea–land contact, a zone of anomalousincrease in the amplitude of ULF variations (F 1 Hz) of the Ex component adjacent to the water’s edge wasrevealed. An additional narrow zone of anomalous amplification of the ULF variations of the electric field isobserved at a distance of ~30 m from the water’s edge. The coastal effect reaches its maximum near thewater’s edge in the coastal zone and decreases with distance from the seashore

New Concept Ocean-Bottom Multiphysics (OBMP) Nodes for Reservoir Monitoring

Marine-controlled source electromagnetics (CSEM) have been extensively applied to various exploration scenarios worldwide. However, its perceived value and cost relative to seismic and the scarcity of realistic case studies have limited the industry’s interest in time-lapse reservoir-monitoring (4D) applications. A feasible way to make demand for CSEM for 4D-monitoring programs would be to increase the value of information and reduce survey costs by performing joint operations where seismic and CSEM data are acquired during the same survey and at equivalent spatial densities. To this end, we propose a new multiphysics ocean-bottom nodes (OBN) concept and show the industry that CSEM can be a cost efficient and effective integrators to 4D seismic projects. To this end, we conducted a feasibility study demonstrating that horizontal magnetic field components have the required sensitivities and can be used instead of horizontal electric field components in mapping the 3D resistivity distribution and 4D fluid change responses in a given reservoir. This makes engineering a new OBN class simpler and cheaper, as various miniaturized magnetic field sensors are available off-the-shelf or readily working along with packaging and coupling solutions.

A Diffuse Interface Approach to Drop Impact Undergoing Solidification under a Horizontal Electric Field

A Diffuse Interface Approach to Drop Impact Undergoing Solidification under a Horizontal Electric Field

Fast iterative solver for 3D finite-element modeling of controlled-source electromagnetic responses with vector and scalar potentials

The controlled-source electromagnetic (CSEM) forward modeling with vector and scalar potentials could provide insights into the inductive and galvanic effects. We have developed a finite-element (FE) forward modeling algorithm for the CSEM with vector and scalar potentials. The first-order vector and nodal shape functions are used for the vector and scalar potentials, respectively. To mitigate the null space and thus the nonuniqueness of the potentials caused by the curl operator, we introduce a new preconditioner constructed from an incomplete Cholesky decomposition with zero fill-ins of the Laplacian approximation to the resulted matrix after the FE discretization. We implemented a preconditioned quasiminimal residual method to iteratively solve the resulting linear system with the new preconditioner. We first verified the accuracy of the algorithm through comparison against the analytic solutions obtained for a three-layered earth model. The new iterative modeling algorithm converges much faster compared with the modeling algorithm with the preconditioner constructed from the original stiffness matrix. The efficiency and accuracy are further illustrated by comparison with the modeling scheme based on coupled potentials with explicit enforcement of the Coulomb gauge condition for the vector potential by modeling three 3D models. In addition, the accuracy of our algorithm is demonstrated via a comparison of our numerical solution for a 3D model with the numerical solution obtained from the integral equation method. We also present the inductive and galvanic components of the horizontal secondary electric field for numerical solutions obtained with direct and iterative solvers. The numerical test demonstrated that, aside from the efficiency improved with the new iterative solver, the unstable and nonuniqueness problem for the potentials is eliminated by the new preconditioner with the Laplacian approximation involved.

Binary Collisions of Water Drops in Presence of Horizontal Electric Fields: A Wind Tunnel Study

AbstractCoalescence/breakup characteristics of binary collisions of small water drops (dS = 0.4–1.8 mm diameter) with large drops (dL = 3–3.5 mm diameter) occurring in the absence/presence of horizontal electric field (EH) = 0, 100, and 300 kVm−1 have been investigated in a small vertical wind tunnel using a high‐speed digital camera. The coalescence efficiency (EC) of 0.299 observed for average diameters (dL = 3.2 mm, dS = 1.2 mm) in EH = 0 decreased to 0.244/0.211 when EH is increased to 100/300 kVm−1. The increase in the electric field reduces the probability of coalescence when Weber number (We) < 1. However, when We ≥ 1, an increase in We restricts the probability of coalescence. Our data, when plotted in the regime diagram in the We*‐p plane, delineates the collision outcomes in all‐electric field values but does show the overlapping of some data points in the adjacent categories. After a binary collision, the relaxation time for coalescence is higher than that for the breakup. Further, the relaxation time increases from the filament to sheet to disk mode of breakup in all‐electric field values. Fragment size distributions after the filament and sheet types of breakups differ and are differently affected by the applied electric field. Higher collision kinetic energy has a tendency to increase the number of fragments of the sizes between dL and dS. It is concluded therefore that, the effect of the electric field needs to be included in the estimation of drop growth and precipitation in clouds.

응답시간이 개선된 액정 기반 능동 반사 배열 안테나 단위 셀 구조

This paper presents a unit cell structure for liquid crystal (LC)-based reconfigurable reflective arrays, aimed at improving the imbalance in response time. Conventional LC-based reflectarray antenna unit cells, which have been widely used as high-gain beam-steerable antennas, have an imbalance in response time because of different alignment of LC molecules during the rise and decay times. By separating the metal layers in contact with the LC layer and applying four bias voltages, we generated both horizontal and vertical electric field. Accordingly, the decay time was improved by unifying the methods in which the LC molecules were aligned during the rise and decay times. Our measurements confirm that the decay time can be reduced to approximately 1/3 compared to the conventional structure, indicating the possibility of resolving the imbalance.

On the nonlinear behaviour of the Rayleigh–Taylor instability with a tangential electric field for inviscid and perfect dielectric fluids

Fluid interfacial instability induced by gravity or external acceleration, known as the Rayleigh–Taylor instability, plays an important role in both scientific research and industrial application. How to control this instability is challenging. Researchers have been actively exploring the suppression method of applying electric fields parallel to dielectric fluid interfaces. The instability is characterized by the penetration of fingers at the interface. The velocities at the finger tips are the most important quantities since they characterize how fast the penetration occurs. The dynamics of the fingers is nonlinear. We present a nonlinear perturbation procedure for determining the amplitude and velocity of fingers at a Rayleigh–Taylor unstable interface between two incompressible, inviscid, immiscible and perfectly dielectric fluids in the presence of a horizontal electric field in two dimensions. The analytic formulas are displayed explicitly up to the third order of the initial disturbance. The comparison with the data from numerical simulations based on the vortex sheet method shows the theoretical formulas can capture well the nonlinear behaviour of the fingers. It is known that the interplay between the electric field and the fluids can lead to the suppression of interfacial instability. We further analyse the electrical force along the interface and show how this force leads to the instability suppression in our setting. It has been reported numerically in the literature that switching the electric permittivities of the fluids leads to quantitative differences in finger velocity. We show theoretically this phenomenon can only be explained by the nonlinear behaviour of the system.

Electrohydrodynamic viscous fingering of leaky dielectric fluids in a channel

Viscous fingering is a commonly observed interfacial instability during fluid displacement, where a fingerlike shape is formed at the fluid interface when a more viscous fluid is displaced by a less viscous fluid. In this study, a hybrid numerical model based on the lattice Boltzmann method and finite difference method is developed for investigating the control of viscous fingering of leaky dielectric fluids confined in a channel using electrohydrodynamics. Extensive simulations are carried out for studying the effects of the strength and direction of the electric field as well as the fluid properties, including the permittivity ratio and conductivity ratio, on viscous fingering. It is shown that a horizontal electric field, i.e., when the direction of the electrical field is perpendicular to the direction of fluid motion, can either promote or suppress the viscous fingering, depending on the permittivity ratio and conductivity ratio. For a vertical electric field, the extent of promotion of viscous fingering first decreases and then increases with the increase in conductivity ratio at a constant permittivity ratio. Also, various interfacial morphologies, such as broad fingers and thin jets, are observed under different fluid properties. A phase diagram for both the horizontal and vertical electric field is established based on the simulations with different permittivity and conductivity ratios to characterize the interfacial morphologies. This study offers insight into the electrohydrodynamic effects on the viscous fingering of leaky dielectric fluids, which could facilitate the control of multiphase flow in various applications, such as enhanced oil recovery and coupled chromatographic systems for separation.

Shadow effect and source overprint effect of short-offset transient electromagnetic method

AbstractIn artificial-source electromagnetic explorations, the shadow effects and source overprint effects are two of the key factors to affect the detection reliability. Compared with frequency-domain electromagnetic methods, the transient electromagnetic (TEM) shadow effect and source overprint effect are more complex, especially for the short-offset TEM (SOTEM) observed in the near-source region. However, there is less relevant research. Therefore, in this paper, we first realize 3D SOTEM simulations based on the vector time-domain finite element method, then further analyze the generation of SOTEM shadow effect and source overprint effect from view of the diffused electromagnetic fields, as well as their influence on ground horizontal electric field Ex and vertical induced voltage dBz/dt responses. Results show that the attraction or repulsion of the electrical inhomogeneity would affect the diffusion speed of the electromagnetic fields, which is the essential in the two source effects. Besides, from view of the ground Ex and dBz/dt responses, the relative anomaly of SOTEM shadow effect is almost twice those of the SOTEM source overprint effect, i.e. the SOTEM shadow effect is easier to record, especially for dBz/dt responses. In addition, owing to the shadow effect, SOTEM may fail to identify the real target anomaly, whereas the influence of the source overprint effect for recognizing the target anomaly mainly occurs on all-time dBz/dt responses and early-time Ex responses (before about 10 ms), that is, observing late-time SOTEM Ex responses can effectively avoid such influence. Hence, to fully ensure avoiding the influence of the source overprint effect, we suggest adopting high-power transmission to increase the late-time signal-to-noise ratio in field measurements.

Optical efficiency modulation of vertical alignment liquid crystal displays with transparent shielding and storage electrode

A high-transmittance vertical alignment liquid crystal display (VA-LCD) using a transparent shielding and storage electrode (TSS) design is proposed. The aperture ratio of the proposed four domain TSS pixel with size of 52 × 156 μm improves approximately by 40% over the conventional pixel due to the shielding and storage metal electrode can be replaced by TSS electrode. Experimental results shown that the transmittance of TSS designed panel with 3.2 μm cell gap is 35% higher than that with conventional pixel design, whereas it is only enhanced by 21% when the cell gap is 2.6 μm. The liquid crystal dynamics simulation results revealed that both the effective birefringence and the azimuthally controlled director profile of the liquid crystal layer decreases with TSS pixel design, and these adverse impacts are magnified as the cell gap decreases. This is due to that the introduction of TSS common electrode not only weakens the vertical electric field but also affects the horizontal electric field of liquid crystal layer, which leads to a greater loss of optical efficiency under lower cell gap, resulting in the worse transmittance promotion. The proposed method is expected to be advantageously employed in enhancing transmittance of VA-LCDs for power saving.

New Insights into the Anomaly Genesis of the Frequency Selection Method: Supported by Numerical Modeling and Case Studies

The frequency selection method (FSM) is the further development of the audio frequency telluric electricity method (TEFM). However, debate continues regarding the mechanisms leading to anomaly genesis. Therefore, the present study intends to explore this using 2D forward modeling of magnetotelluric (MT) sounding and practical applications of FSM on three Chinese case studies in karst and granitic settings. In the first stage, the profile curves and pseudo-section of apparent resistivity ( $${\rho }_{s}$$ ) and horizontal electric field component $${(E}_{y})$$ in MT mode are obtained by forward calculation. As a result, the static shift in $${\rho }_{s}$$ is observed over the near-surface inhomogeneities, as documented in the literature. Additionally, the profile curves of $${E}_{y}$$ showed an obvious static shift in the rectangular coordinate system (i.e., the curve rises with the increase in frequency) which is a well-known phenomenon. The pseudo-sections of $${E}_{y}$$ also showed static shift characteristics at the horizontal position above the anomaly, referred to as the “noodles phenomenon.” The FSM results were obtained from case studies related to groundwater and low-resistivity clay-filled karst body identification. The $$\Delta V$$ section curves and pseudo-section showed a significant low potential, and a “noodles phenomenon,” respectively, above the low-resistivity anomalous body. These abnormal characteristics of $$\Delta V$$ are the basis for delineating the horizontal position of the groundwater aquifer by applying FSM. It is concluded that the anomaly of FSM is the reflection of the static shift in MT, and hence, the FSM can be categorized as a “static shift method.” Therefore, this inspired us to investigate whether the static shift feature of the surface $${E}_{y}$$ component could be utilized to explore near-surface geological bodies such as clay-filled or water-filled cavities.

Electrically Manipulated Vapor Condensation on the Dimpled Surface: Insights from Molecular Dynamics Simulations.

Random vapor nucleation leads to flooding condensation with degraded heat-transfer efficiency. Since an external electric field has a significant effect on manipulating droplets' motion, it is possible to be one of the effective methods to hinder flooding phenomena and improve the heat-transfer rate by applying the external electric field during condensation. However, the motion of nanodroplets is more sensitive to the electric field owing to the scale effect on the nanoscale. The effect of the electric field on growth has not explicitly been comprehended. This work studied the condensation processes on a nanodimpled surface under an electric field with various strengths and directions. The results showed that condensed droplets' growth under the electric field depends on the competition between the electric field force and solid-liquid interactions. Increased vertical electric field strength, the higher torsion by the electric field hindered the motion of vapor, decreased the collision frequency for water molecules with the cooled surface, and elongated the cluster when the electric field force dominates, thus deteriorating the condensation performance. While applying the horizontal electric field, the greater electric field strength leads to better condensation performance by the larger contacting area for heat exchange. A wetting transition induced by the electric field was observed when the electric field strength increased to a certain extent (E > 5.2 × 108 V/m in this study). When the V-shaped surface replaced the dimpled surface as the condensed substrate, the same wetting transition phenomena occurred under a more significant horizontal electric field strength, showing that this method is universal. Besides, different electric field frequencies influenced both the growth and the nucleation, thus exhibiting various condensation performances.

Extraction of Multiple Electrical Parameters From IP-Affected Transient Electromagnetic Data Based on LSTM-ResNet

The induced polarization (IP) effect due to a polarizable body distorts transient electromagnetic (TEM) data, thereby potentially triggering sign reversal phenomena in the measured response. The measured horizontal electric field associated with a grounded-wire TEM is more strongly affected by IP effects than the measured vertical field, meaning that data inversion is more problematic for its component. The traditional inversion method, which assumes a frequency independent resistivity, is complex to extract the chargeability. Yet, the chargeability provides critical information, so it is important to extract the chargeability in addition to the resistivity from IP-affected TEM data. Thus, we proposed a data-driven method based on deep learning to recover the resistivity and chargeability of IP-affected horizontal electric fields. This method, named LSTM-ResNet, combines long short-term memory (LSTM) and a residual network (ResNet) to estimate subsurface electrical properties. Synthetic tests showed that LSTM-ResNet is computationally efficient and accurate for inversion problems. Based on the inverse results with data added noise, we found that a well-trained neural network was not sensitive to noise. A case study was performed by applying LSTM-ResNet to field data collected by a grounded-wire TEM survey at the Kalatongke copper-nickel ore deposit. LSTM-ResNet recovered the simultaneous resistivity and chargeability distributions of subsurface structures from the IP-affected horizontal electric TEM field. The results show a high-chargeability and low-resistivity layer, which was consistent with the lithologic profiles based on drilling cores, indicating the accuracy and robustness of the proposed framework for multi-parameter inversion.