Electric Field Measurements Research Articles

Precision 3D Underwater Electric Field Measurement Method for Accurate Marine Localization

Precision 3D Underwater Electric Field Measurement Method for Accurate Marine Localization

Effect of outer spherical shell opening structure on the sensitivity of double spherical shell electric field sensor.

A double spherical shell (DSS) electric field sensor based on charge sensing has characteristics of small size and simple fabrication, which are appropriate for measuring complex electric field environments, but the sensitivity is low. To improve the sensitivity of the DSS electric field sensor, we theoretically analyze the effect of the diameter of the outer spherical shell opening on the sensitivity of the sensor. The sensors with outer spherical shell apertures of 2, 4, and 6mm are designed and manufactured, and the sensor's sensitivity, linearity, hysteresis, and repeatability are tested. The relative error of the sensor is evaluated by measuring the rotational characteristics of the sensor. The experimental results show that the sensor sensitivity increases with the increase in hole diameter, while the sensor has good linearity, hysteresis, and repeatability after opening the hole. The rotational characteristics experiments' results show that the sensors' relative errors with different apertures are 18, 23, and 31%, respectively. The DSS open-hole structure is more suitable for electric field measurements than the conventional flat plate structure.

Research on hand-held power frequency electric field measurement safety warning system

Research on hand-held power frequency electric field measurement safety warning system

Calculation and experiment of tiny perturbations in electric field measurement for the laser-induced fluorescence-dip spectroscopy method

Calculation and experiment of tiny perturbations in electric field measurement for the laser-induced fluorescence-dip spectroscopy method

Robustness evaluation of electric field measurements via template matching in 4D-STEM

Robustness evaluation of electric field measurements via template matching in 4D-STEM

Continuous broadband microwave electric field measurement in Rydberg atoms based on the DC Stark effect

We demonstrate a method for broadband tunable continuous frequency electric field measurement based on the DC Stark effect in Rydberg atoms. In our experiment, we place a pair of parallel electrode plates inside the atomic vapor cell, utilizing the DC Stark effect to induce splitting and shifting of the Rydberg energy levels, thereby altering the resonance frequency of the Stark subpeaks. By employing the 52D5/2 Rydberg state, we achieve electric field measurements in the frequency range of 5.083–14.470 GHz. At an EDC of 3.45 V/cm and a resonant microwave frequency of 14.470 GHz, using heterodyne technology, the microwave electric field sensitivity is 538.89 μV/cm/√Hz, with a linear dynamic range of 23 dB. In comparison, a Rydberg heterodyne receiver with an EDC of 0 V/cm and a resonant microwave frequency of 5.083 GHz has a sensitivity of 5.43 μV/cm/√Hz and a linear dynamic range of 51 dB. This work will promote the study of atomic microwave receivers in continuous microwave frequency measurement.

Interaction of in-plane Drude carrier with c-axis phonon in PdCoO2

We performed polarized reflection and transmission measurements on the layered conducting oxide PdCoO2 thin films. For the ab-plane, an optical peak near Ω ≈ 750 cm−1 drives the scattering rate 1/τ(ω) and effective mass m*(ω) of the Drude carrier to increase and decrease respectively for ω ≧ Ω. For the c-axis, a longitudinal optical phonon (LO) is present at Ω as evidenced by a peak in the loss function Im[−1/εc(ω)]. Further polarized measurements in different light propagation (q) and electric field (E) configurations indicate that the Peak at Ω results from an electron-phonon coupling of the ab-plane carrier with the c-LO phonon, which leads to the frequency-dependent 1/τ(ω) and m*(ω). This unusual interaction was previously reported in high-temperature superconductors (HTSC) between a non-Drude, mid-infrared (IR) band and a c-LO. On the contrary, it is the Drude carrier that couples in PdCoO2. The coupling between the ab-plane Drude carrier and c-LO suggests that the c-LO phonon may play a significant role in the characteristic ab-plane electronic properties of PdCoO2, including the ultra-high dc-conductivity, phonon-drag, and hydrodynamic electron transport.

Automatic Identification and Statistical Analysis of Data Steps in Electric Field Measurements from CSES-01 Satellite

The spaceborne Electric Field Detector (EFD) is one of the payloads of the China Seismo-Electromagnetic Satellite (CSES-01), which can measure electric field data at near-Earth orbit for investigating fundamental scientific topics such as the dynamics of the top-side ionosphere, lithosphere–atmosphere–ionosphere coupling, and electromagnetic field emissions possibly associated with earthquake occurrence. The Extremely Low-Frequency (ELF) waveform shows anomalous step variations, and this work proposes an automatic detection algorithm to identify steps and analyze their characteristics using a convolutional neural network. The experimental results show that the developed detection method is effective, and the identification performance reaches over 90% in terms of both accuracy and area under the curve index. We also analyze the rate of the occurrence of steps in the three components of the electric field. Finally, we discuss the stability of the statistical results on steps and their relevance to the probe’s function. The research results provide a guideline for improving the quality of EFD data, and further applications in monitoring the low-Earth electromagnetic environment.

Simultaneous Measurement of Electric and Magnetic Fields With a High-Sensitivity Differential Composite Probe

Simultaneous Measurement of Electric and Magnetic Fields With a High-Sensitivity Differential Composite Probe

Toward the Measurement of Microwave Electric Field Using Cesium Vapor MEMS Cell

Toward the Measurement of Microwave Electric Field Using Cesium Vapor MEMS Cell

Effect of laser detuning and Rabi frequency on rubidium Rydberg electromagnetically-induced transparency for atom-based electric field sensing

Atom-based electromagnetic field sensing is a highly precise and sensitive technique for measuring and detecting electromagnetic fields, based on the principles of the Rydberg electromagnetically induced transparency (EIT). In this study, we simulate an atom-based electric field measurement system using a four-level system of rubidium atoms. We solve the steady-state solution of the Lindblad master equation using a Hamiltonian that contains information about rubidium properties and the external electric field. We observe that the splitting of the EIT signal is directly proportional to the intensity of the applied electric field, making it a highly sensitive method for electromagnetic field sensing. In addition, we investigate the effect of laser detuning and Rabi frequency on the linewidth and signal strength of the EIT signal in order to obtain optimal parameters for future experiments. This study provides insights into optimizing the EIT signal for electromagnetic fields detection, with potential benefits for future developments in this field.

No Response of Surface-Level Atmospheric Electrical Parameters in Israel to Severe Space Weather Events

We report ground-based measurements of the atmospheric electric field (Ez = −potential gradient (PG)) and current density (Jz) that were conducted at two locations in Israel. One is at the Emilio Segre cosmic ray station located on Mt. Hermon (34.45° N, 2020 m AMSL) in northern Israel near the Syrian-Lebanon border, and the other is at the Wise astronomical observatory in the Negev desert highland plateau of southern Israel (31.18° N, 870 m AMSL). We searched for possible effects of strong, short-term solar events on the potential gradient and the vertical current density, as disruptions to the global electric circuit are often observed following strong solar events. The first case study (St. Patrick’s Day, 17 March 2015) was classified as the strongest event of 2015. The second case study (8 September 2017) was categorized as the strongest event of 2017 and one of the twenty strongest events on record to date. The results show that the electrical parameters measured at ground level at both stations were not affected during the two massive proton events and the ensuing geomagnetic storms. The magnetospheric shielding in lower latitudes is strong enough to shield against the flux of energetic particles from solar events, obscuring any impact that may be noticeable above the local daily variations induced by local meteorological conditions (aerosol concentrations, clouds, high humidity, and wind speed), which were investigated as well.

Magnetic-field-induced splitting of Rydberg Electromagnetically Induced Transparency and Autler-Townes spectra in 87Rb vapor cell.

We theoretically and experimentally investigate the Rydberg electromagnetically induced transparency (EIT) and Autler-Townes (AT) splitting of 87Rb vapor under the combined influence of a magnetic field and a microwave field. In the presence of static magnetic field, the effect of the microwave field leads to the dressing and splitting of each mF state, resulting in multiple spectral peaks in the EIT-AT spectrum. A simplified analytical formula was developed to explain the EIT-AT spectrum in a static magnetic field, and the theoretical calculations agree qualitatively with experimental results. The Rydberg atom microwave electric field sensor performance was enhanced by making use of the splitting interval between the two maximum absolute mF states separated by the static magnetic field, which was attributed to the stronger Clebsch-Gordon coefficients between the extreme mF states and the frequency detuning of the microwave electric field under the static magnetic field. The traceable measurement limit of weak electric field by EIT-AT splitting method was extended by an order of magnitude, which is promising for precise microwave electric field measurement.

Estimating the corotation lag of the plasmasphere based on the electric field measurements of the Van Allen Probes

The corotation electric field driving the plasmasphere to corotate with the Earth body is important in establishing the topology of the inner magnetosphere and is usually calculated by assuming a 24 h corotation period. However, studies have found that a plasmasphere corotation lag exists, suggesting an overestimation of the electric field driving the plasmasphere to rotate with the planet in previous calculations. In this study, we use electric field measurements from the Van Allen Probes mission from 2012 to 2018 to obtain the distribution of the large-scale electric field in the inner magnetosphere. A new method is developed to extract plasmaspheric rotation information from electric field measurements. Our results show that the electric field driving the plasmaspheric rotation varies with magnetic activity, decreasing with increasing Kp index. It is thus suggested that the corotation lag of the plasmasphere is more significant during magnetically active periods.

Non-invasive temporal interference electrical stimulation of the human hippocampus

Deep brain stimulation (DBS) via implanted electrodes is used worldwide to treat patients with severe neurological and psychiatric disorders. However, its invasiveness precludes widespread clinical use and deployment in research. Temporal interference (TI) is a strategy for non-invasive steerable DBS using multiple kHz-range electric fields with a difference frequency within the range of neural activity. Here we report the validation of the non-invasive DBS concept in humans. We used electric field modeling and measurements in a human cadaver to verify that the locus of the transcranial TI stimulation can be steerably focused in the hippocampus with minimal exposure to the overlying cortex. We then used functional magnetic resonance imaging and behavioral experiments to show that TI stimulation can focally modulate hippocampal activity and enhance the accuracy of episodic memories in healthy humans. Our results demonstrate targeted, non-invasive electrical stimulation of deep structures in the human brain.

The Influence of the Atmospheric Electric Field on Soil Redox Potential

Atmospheric electric fields (AEFs) have recently been proposed to link to biogeochemical processes below the Earth’s surface by means of a charge separation. Despite the potential importance of such a process, up to now we almost completely lack the relevant measurements. Here, we extend the database with 2 months of concurrent soil redox and atmospheric electric field measurements. It appears that the changes that occur in the order of days in soil redox are at periods anticorrelated with the logarithm of the positive values of the AEF. However, weather conditions might be driving the anticorrelation rather than a direct link, as the synoptic weather conditions appear to influence soil redox. Soil redox does not respond to changes in the AEF that are of shorter duration, either minutes or several hours, except in some cases of very negative AEFs or very high field strengths in the presence of moderate rainfall. In such a case, the variation in soil redox could be associated with a mechanism that transfers charge to the ground or brings ions towards the ground’s surface. To reach firmer conclusions on the effect of the AEF on soil redox, we need to extend the range of collocated soil redox and AEF measurements so that they cover at least one year.

Continued atmospheric electric field measurements following cessation of the long‐term water dropper potential equalizer at Kakioka, Japan

AbstractSurface atmospheric electric field (AEF) measurements were conducted using a Kelvin water dropper equalizer by the Japan Meteorological Agency's geomagnetic observatory at Kakioka, Ibaraki Prefecture, Japan, from 1929 to February 28, 2021. To obtain AEF data successive to the water dropper measurement, we independently installed the field mills at Kakioka. In this present study, we estimated the calibration coefficients based on comparisons between the water dropper and the field mills through parallel observations over 3 days. The results revealed that the new observations could be regarded as continuous data. Our new data from the field mills in this study have begun the process of being distributed in GLObal Coordination of Atmospheric Electricity Measurements (GloCAEM) as both archived and real‐time data in 1 min and 1 s samplings.

Electric field control of magnetization in polycrystalline ZnO film

A polycrystalline ZnO film is grown on a silicon substrate by the pulsed laser deposition method, and the electric field-induced magnetization in ZnO using an optical cantilever beam magnetometer setup is studied. The magnetization vs bipolar dc electric field measurements reveal the occurrence of magnetization switching in the ZnO film. The magnetization switching in the presence of an electric field is ascribed to the converse magnetoelectric (ME) coupling that takes place between the electrical and the magnetic order parameters existing in the ZnO film. We have found the strain-driven magnetization change as evidenced by the butterfly shape of the magnetization vs the electric field curve. A saturation magnetization of 13.31 MA/m is obtained. Moreover, a significant value of the ME coupling coefficient (α) (1.61 × 10−7 s/m) has also been reported in this article. The emergence of electric field-induced magnetization in a single polycrystalline ZnO film is regarded to be a very promising aspect in designing high-density energy-efficient spintronic and different multifunctional devices.

Saturated cavity ringdown spectroscopy at Balmer-α lineof atomic hydrogen for estimating sheath electric field in plasma

We applied saturated cavity ringdown spectroscopy (CRDS) to the measurement of the Doppler-free absorption spectrum of the Balmer-α line of atomic hydrogen in an inductively coupled hydrogen plasma. The spectrum was used for estimating the electric field in the sheath region in the vicinity to a biased electrode. The absorption frequency (the absorption coefficient multiplied by the speed of light) and the saturation parameter were estimated by fitting the experimental ringdown curve with the theory reported by Giusfredi and coworkers (Phys. Rev. Lett. 104 (2010) 110801). We detected the Lamb dip corresponding to the 2p 2 P o 3/2 - 3d 2 D 5/2 transition in the absorption spectrum in the field-free condition. We observed the change in the Lamb dip spectrum when we repeated the measurement in the sheath, and we succeeded in estimating the sheath electric field of 220–230 V/cm at a distance of 1.8 mm from the electrode which was biased at -100 V with respect to the ground potential. The experimental results indicate the potential of saturated CRDS for the measurement of sheath electric fields in plasmas.

A Ti: LiNbO3 optical waveguide sensor for measurement of intensive electric field

In this paper, a Ti: LN optical waveguide intensive electric field sensor without metal structure is designed and fabricated. By using the finite element simulation, the refractive index difference Δno and Δne of the waveguide are designed as 0.0105 and 0.0305 respectively when the prediffusion depth d is 5 μm, which results in the static operating point of the sensor is 86.4° when the length L is 45 mm and the prediffusion width w is 10 μm. The simulation results show that when the design of LN substrate is 6 mm (x) × 1 mm (y) × 45 mm (z), the ratio of the external and internal electric fields is 4.216, and the half-wave electric field is 10053 kV/m. The sensor is measured by the power-frequency electric field measurement system, and the half-wave electric field is about 10135 kV/m, and the maximum detectable electric field is about 3041 kV/m.