The Application of Low-Frequency Transition in the Assessment of the Second-Order Zeeman Frequency Shift

Second-order Zeeman frequency shift is one of the major systematic factors affecting the frequency uncertainty performance of cesium atomic fountain clock. Second-order Zeeman frequency shift is calculated by experimentally measuring the central frequency of the (1,1) or (−1,−1) magnetically sensitive Ramsey transition. The low-frequency transition method can be used to measure the magnetic field strength and to predict the central fringe of (1,1) or (−1,−1) magnetically sensitive Ramsey transition. In this paper, we deduce the formula for magnetic field measurement using the low-frequency transition method and measured the magnetic field distribution of 4 cm inside the Ramsey cavity and 32 cm along the flight region experimentally. The result shows that the magnetic field fluctuation is less than 1 nT. The influence of low-frequency pulse signal duration on the accuracy of magnetic field measurement is studied and the optimal low-frequency pulse signal duration is determined. The central fringe of (−1,−1) magnetically sensitive Ramsey transition can be predicted by using a numerical integrating of the magnetic field “map”. Comparing the predicted central fringe with that identified by Ramsey method, the frequency difference between these two is, at most, a fringe width of 0.3. We apply the experimentally measured central frequency of the (−1,−1) Ramsey transition to the Breit-Rabi formula, and the second-order Zeeman frequency shift is calculated as 131.03 × 10−15, with the uncertainty of 0.10 × 10−15.

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Range Detection of the Extremely Low-Frequency Magnetic Field Produced by Laptop’s AC Adapter

Measurement Science Review ◽

10.1515/msr-2017-0001 ◽

2017 ◽

Vol 17 (1) ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Darko Brodić ◽

Alessia Amelio

Keyword(s):

Magnetic Field ◽

Low Frequency ◽

Operating Conditions ◽

Magnetic Field Measurement ◽

Field Exposure ◽

Heavy Load ◽

Safety Standards ◽

Extremely Low Frequency ◽

Frequency Magnetic Field ◽

The Magnetic Field

Abstract Human exposure to extremely low frequency magnetic field represents a risk to their health. This paper takes into consideration the level of an extremely low-frequency magnetic field between 30 and 300 Hz emitted by an AC laptop adapter. The experiment consists of testing 17 different AC adapters for laptops. During the testing, laptops are operated in a normal operating conditions as well as under heavy load. The magnetic field measurement is conducted in the area around the AC adapter. Obtained data is evaluated according to the critical level of the magnetic field proposed by safety standards. Furthermore, data is classified by a K-medians method in order to determine the critical levels of the magnetic field exposure in the nearby area of the AC adapter. Obtained classifications are evaluated according to safety standards, giving a critical analysis of magnetic field areas at risk. Due to emission of a very strong magnetic field in certain areas, a recommendation for safety use of the AC adapter is proposed.

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PEMANFAATAN RADIASI ENERGI TEGANGAN 150 KV UNTUK LAMPU LED PENERANGAN JALAN

Jurnal Teknik ◽

10.31000/jt.v7i1.936 ◽

2018 ◽

Vol 7 (1) ◽

Author(s):

Mauludi Manfaluthy

Keyword(s):

Magnetic Field ◽

Electric Field ◽

High Voltage ◽

Low Frequency ◽

Energy Utilization ◽

World Health ◽

Electromagnetic Signals ◽

Health Organization ◽

The Magnetic Field ◽

Low Frequency Waves

WHO (World Health Organization) concludes that not much effect is caused by electric field up to 20 kV / m in humans. WHO standard also mentions that humans will not be affected by the magnetic field under 100 micro tesla and that the electric field will affect the human body with a maximum standard of 5,000 volts per meter. In this study did not discuss about the effect of high voltage radiation SUTT (High Voltage Air Channel) with human health. The research will focus on energy utilization of SUTT radiation. The combination of electric field and magnetic field on SUTT (70-150KV) can generate electromagnetic (EM) and radiation waves, which are expected to be converted to turn on street lights around the location of high voltage areas or into other forms. The design of this prototype works like an antenna in general that captures electromagnetic signals and converts them into AC waves. With a capacitor that can store the potential energy of AC and Schottky diode waves created specifically for low frequency waves, make the current into one direction (DC). From the research results obtained the current generated from the radiation is very small even though the voltage is big enough.Keywords : Radiance Energy, Joule Thief, and LED Module.

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Integral Equations for Problems on Wave Propagation in Near-Earth Plasma

Symmetry ◽

10.3390/sym13081395 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1395

Author(s):

Danila Kostarev ◽

Dmitri Klimushkin ◽

Pavel Mager

Keyword(s):

Magnetic Field ◽

Integral Equations ◽

Field Potential ◽

Low Frequency ◽

Fredholm Equation ◽

Compression Waves ◽

Parallel Component ◽

Electric Field Potential ◽

The Magnetic Field ◽

Low Frequency Waves

We consider the solutions of two integrodifferential equations in this work. These equations describe the ultra-low frequency waves in the dipol-like model of the magnetosphere in the gyrokinetic framework. The first one is reduced to the homogeneous, second kind Fredholm equation. This equation describes the structure of the parallel component of the magnetic field of drift-compression waves along the Earth’s magnetic field. The second equation is reduced to the inhomogeneous, second kind Fredholm equation. This equation describes the field-aligned structure of the parallel electric field potential of Alfvén waves. Both integral equations are solved numerically.

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First in-orbit results of the vector magnetic field measurement of the High Precision Magnetometer onboard the China Seismo-Electromagnetic Satellite

Earth Planets and Space ◽

10.1186/s40623-019-1098-3 ◽

2019 ◽

Vol 71 (1) ◽

Cited By ~ 4

Author(s):

Bin Zhou ◽

Bingjun Cheng ◽

Xiaochen Gou ◽

Lei Li ◽

Yiteng Zhang ◽

...

Keyword(s):

Magnetic Field ◽

High Precision ◽

Magnetic Field Measurement ◽

Vector Data ◽

Magnetic Field Data ◽

Night Side ◽

The Difference ◽

The Magnetic Field ◽

Ground Calibration ◽

Data Calibration

Abstract The High Precision Magnetometer (HPM) is one of the main payloads onboard the China Seismo-Electromagnetic Satellite (CSES). The HPM consists of two Fluxgate Magnetometers (FGM) and the Coupled Dark State Magnetometer (CDSM), and measures the magnetic field from DC to 15 Hz. The FGMs measure the vector components of the magnetic field; while the CDSM detects the magnitude of the magnetic field with higher accuracy, which can be used to calibrate the linear parameters of the FGM. In this paper, brief descriptions of measurement principles and performances of the HPM, ground, and in-orbit calibration results of the FGMs are presented, including the thermal drift and magnetic interferences from the satellite. The HPM in-orbit vector data calibration includes two steps: sensor non-linearity corrections based on on-ground calibration and fluxgate linear parameter calibration based on the CDSM measurements. The calibration results show a reasonably good stability of the linear parameters over time. The difference between the field magnitude calculated from the calibrated FGM components and the magnitude directly measured by the CDSM is just 0.5 nT (1σ) when the linear parameters are fitted separately for the day- and the night-side. Satellite disturbances have been analyzed including soft and hard remanence as well as magnetization of the magnetic torquer, radiation from the Tri-Band Beacon, and interferences from the rotation of the solar wing. A comparison shows consistency between the HPM and SWARM magnetic field data. Observation examples are introduced in the paper, which show that HPM data can be used to survey the global geomagnetic field and monitor the magnetic field disturbances in the ionosphere.

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Reversibility of the Magnetocaloric Effect in the Bean-Rodbell Model

Magnetochemistry ◽

10.3390/magnetochemistry7050060 ◽

2021 ◽

Vol 7 (5) ◽

pp. 60

Author(s):

Luis M. Moreno-Ramírez ◽

Victorino Franco

Keyword(s):

Magnetic Field ◽

Thermal Hysteresis ◽

Entropy Change ◽

Second Order ◽

Zero Field ◽

First Order ◽

Magnetic Field Change ◽

Magnetocaloric Materials ◽

Moderate Magnetic Field ◽

The Magnetic Field

The applicability of magnetocaloric materials is limited by irreversibility. In this work, we evaluate the reversible magnetocaloric response associated with magnetoelastic transitions in the framework of the Bean-Rodbell model. This model allows the description of both second- and first-order magnetoelastic transitions by the modification of the η parameter (η<1 for second-order and η>1 for first-order ones). The response is quantified via the Temperature-averaged Entropy Change (TEC), which has been shown to be an easy and effective figure of merit for magnetocaloric materials. A strong magnetic field dependence of TEC is found for first-order transitions, having a significant increase when the magnetic field is large enough to overcome the thermal hysteresis of the material observed at zero field. This field value, as well as the magnetic field evolution of the transition temperature, strongly depend on the atomic magnetic moment of the material. For a moderate magnetic field change of 2 T, first-order transitions with η≈1.3−1.8 have better TEC than those corresponding to stronger first-order transitions and even second-order ones.

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Spacecraft and interplanetary contributions to the magnetic environment on-board LISA Pathfinder

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa830 ◽

2020 ◽

Vol 494 (2) ◽

pp. 3014-3027

Author(s):

M Armano ◽

H Audley ◽

J Baird ◽

P Binetruy ◽

M Born ◽

...

Keyword(s):

Magnetic Field ◽

New Technologies ◽

Magnetic Measurements ◽

Magnetic Measurement ◽

Low Frequency ◽

Lisa Pathfinder ◽

Frequency Regime ◽

The Magnetic Field ◽

Instrument Sensitivity ◽

Stationary Component

ABSTRACT LISA Pathfinder (LPF) has been a space-based mission designed to test new technologies that will be required for a gravitational wave observatory in space. Magnetically driven forces play a key role in the instrument sensitivity in the low-frequency regime (mHz and below), the measurement band of interest for a space-based observatory. The magnetic field can couple to the magnetic susceptibility and remanent magnetic moment from the test masses and disturb them from their geodesic movement. LPF carried on-board a dedicated magnetic measurement subsystem with noise levels of 10 $\rm nT \ Hz^{-1/2}$ from 1 Hz down to 1 mHz. In this paper we report on the magnetic measurements throughout LPF operations. We characterize the magnetic environment within the spacecraft, study the time evolution of the magnetic field and its stability down to 20 μHz, where we measure values around 200 $\rm nT \ Hz^{-1/2}$, and identify two different frequency regimes, one related to the interplanetary magnetic field and the other to the magnetic field originating inside the spacecraft. Finally, we characterize the non-stationary component of the fluctuations of the magnetic field below the mHz and relate them to the dynamics of the solar wind.

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ANALYSIS OF HIGH-FREQUENCY C-CORE MAGNETIC FLUX LEAKAGES FOR BONE TUMOR WITH INDUCTION HEATING BY USING MULTI-COIL

Proceedings 17th International Conference on Microwave and High Frequency Heating ◽

10.4995/ampere2019.2019.9900 ◽

2019 ◽

Author(s):

Metharak Jokpudsa ◽

Supawat Kotchapradit ◽

Chanchai Thongsopa ◽

Thanaset Thosdeekoraphat

Keyword(s):

Magnetic Field ◽

High Frequency ◽

Tumor Tissue ◽

Low Frequency ◽

Heat Energy ◽

High Frequencies ◽

Frequency Magnetic Field ◽

High Frequency Magnetic Field ◽

The Magnetic Field ◽

Flux Leakage

High-frequency magnetic field has been developed pervasively. The induction of heat from the magnetic field can help to treat tumor tissue to a certain extent. Normally, treatment by the low-frequency magnetic field needed to be combined with magnetic substances. To assist in the induction of magnetic fields and reduce flux leakage. However, there are studies that have found that high frequencies can cause heat to tumor tissue. In this paper present, a new magnetic application will focus on the analysis of the high-frequency magnetic nickel core with multi-coil. In order to focus the heat energy using a high-frequency magnetic field into the tumor tissue. The magnetic coil was excited by 915 MHz signal and the combination of tissues used are muscle, bone, and tumor. The magnetic power on the heating predicted by the analytical model, the power loss density (2.98e-6 w/m3) was analyzed using the CST microwave studio.

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Magnetic Recording Method (MRM) for Nondestructive Evaluation of Ferromagnetic Materials

Materials ◽

10.3390/ma15020630 ◽

2022 ◽

Vol 15 (2) ◽

pp. 630

Author(s):

Tomasz Chady ◽

Ryszard D. Łukaszuk ◽

Krzysztof Gorący ◽

Marek J. Żwir

Keyword(s):

Magnetic Field ◽

Magnetic Recording ◽

Permanent Magnets ◽

Steel Structure ◽

Standard Technique ◽

Magnetic Field Measurement ◽

Destructive Testing ◽

Recording Method ◽

Nondestructive Testing Method ◽

The Magnetic Field

This paper proposes and experimentally investigates a novel nondestructive testing method for ferromagnetic elements monitoring, the Magnetic Recording Method (MRM). In this method, the inspected element must be magnetized in a strictly defined manner before operation. This can be achieved using an array of permanent magnets arranged to produce a quasi-sinusoidal magnetization path. The magnetic field caused by the original residual magnetization of the element is measured and stored for future reference. After the operation or loading, the magnetic field measurement is repeated. Analysis of relative changes in the magnetic field (for selected components) allows identifying applied stress. The proposed research methodology aims to provide information on the steel structure condition unambiguously and accurately. An interpretation of the results without referring to the original magnetization is also possible but could be less accurate. The method can be used as a standard technique for NDT (Non-Destructive Testing) or in structural health monitoring (SHM) systems.

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Low Frequency Measurements in Amorphous Wire for Studying GMI Effect

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.495.201 ◽

2011 ◽

Vol 495 ◽

pp. 201-204

Author(s):

Polykseni Vourna

Keyword(s):

Magnetic Field ◽

Low Frequency ◽

Major Change ◽

Wheatstone Bridge ◽

Amorphous Wire ◽

Dc Voltage ◽

Gmi Effect ◽

Offset Voltage ◽

Ac Current ◽

The Magnetic Field

When a soft ferromagnetic material is flown by an ac current and a magnetic field is applied at the same time, a major change of its impedance is occurred. The aim of this paper is to investigate the influence of low frequency (1KHz-12KHz) ac current and the applied magnetic field on an amorphous magnetic wire (Co68Fe4.35Si12.5B15) without glass coating. For this purpose an experimental configuration has been setup, based on a Wheatstone bridge which receives an ac input signal from a frequency generator. The output is connected to the amorphous wire wrapped with a coil supplied by a dc voltage for the generation of the magnetic field. The output voltage pulse is measured for two cases a) The value of ac frequency is changing while the value of dc voltage applied to the coil remains constant (the magnetic field remains unchanged) and b) the magnetic field is changing while the ac frequency remains constant to a predefined value. Experimental results of the first scenario showed that when the frequency is altered a non-linear increase of the ac signal is observed at the output which shows an increase of the GMI effect and is related to the non-linearity of the wire’s permeability. For the second scenario the results showed an increase of the output signal offset (voltage) which also indicates an increase of the GMI effect.

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