Equivalent Path and Absorption for Electromagnetic Radiation in the Solar Corona

1950 ◽  
Vol 3 (3) ◽  
pp. 376 ◽  
Author(s):  
JC Jaeger ◽  
KC Westfold
Keyword(s):  
Magnetic Fields ◽  
Solar Corona ◽  
Electromagnetic Radiation ◽  
Spherical Symmetry ◽  
Solar Disk ◽  
Frequency Range ◽  
Echo Signal

Calculations of the trajectories, equivalent path, and absorption of rays, in the frequency range 20-100 Mc/s., in the solar corona have been made, neglecting possible magnetic fields and assuming spherical symmetry. Interpreting the double-humped burst of solar noise as the superposition of a direct and an echo signal, inferences are made as to the height in the corona and location on the solar disk of its source.

Electromagnetic fields at work places experts of the cellular companies

10.12737/5019 ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 1-4
Author(s):  
Горохов ◽  
E. Gorokhov ◽  
Ляпкало ◽  
A. Lyapkalo
Keyword(s):  
Magnetic Fields ◽  
Electromagnetic Radiation ◽  
Electromagnetic Fields ◽  
Electric Fields ◽  
Working Conditions ◽  
Base Stations ◽  
Frequency Range ◽  
Magnetic Components ◽  
Electronic Computers ◽  
The Impact

The paper presents the results of instrumental studies by means of hygienic assessment of levels of electromagnetic fields (EMF) on the workplaces in cellular companies. Measurements of EFM were made on workplaces of 2 groups of employees during the studies: office administrative specialists and technical employees. Instrumental measurements of EMF levels were made by Personal Electronic Computers (PCs) and receivingtransmitting equipment of base cellular stations (BCS). Measurements of EMF from the PC´s screens based on electric and magnetic components were performed: a tension of electric fields with a frequency range of 5Hz-2 kHz and 2 kHz-4 kHz; a tension of magnetic fields in the frequency range of 5Hz-2 kHz and 2 kHz-4 kHz. Measurements of flux density of electromagnetic energy were performed at operating platforms of base stations and at control operating equipment rooms of cellular stations. There were about 150 workplaces of office administrative specialists with PCs surveyed and more 500 workplaces of technical specialists. The activities of administrations of cellular companies were estimated to ensure the safety of working conditions of employees under the influence of electromagnetic radiation (EMR). Literature data on the impact of EMR on human health and health of employees were presented.

MEASURING ACTIVE FERRITE ANTENNA AFA-1M

2020 ◽  
Author(s):  
Ю.А. Никитин ◽  
С.А. Белов ◽  
С.Ю. Чернявский
Keyword(s):  
Magnetic Fields ◽  
Electromagnetic Radiation ◽  
Electromagnetic Fields ◽  
Frequency Range ◽  
Measuring Systems ◽  
Independent Product

В статье описана малогабаритная широкополосная активная ферритовая антенна АФА-1М для измерений магнитных полей в диапазоне частот от 10 Гц до 300 кГц. Антенна может быть использована как самостоятельное изделие, так и в составе автоматизированных измерительных комплексов для измерения электромагнитных полей помех, а также для проверки системы защиты информации от непреднамеренной утечки за счет побочных электромагнитных излучений. The article describes the small-sized broadband active ferrite antenna AFA-1M for measuring magnetic fields in the frequency range from 10 Hz to 300 kHz. The antenna can be used as an independent product and as a part of automated measuring systems for measuring electromagnetic fields of interference, as well as to verify the protection of information from unintentional leakage due to spurious electromagnetic radiation.

Calculated Coronal Magnetic Fields and Their Comparison with the Coronal Structures as Observed during Five Solar Eclipses

1994 ◽  
Vol 144 ◽  
pp. 559-564
Author(s):  
P. Ambrož ◽  
J. Sýkora
Keyword(s):  
Magnetic Field ◽  
Solar Cycle ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Coronal Magnetic Field ◽  
Coronal Magnetic Fields ◽  
Solar Eclipses ◽  
Coronal Structures

AbstractWe were successful in observing the solar corona during five solar eclipses (1973-1991). For the eclipse days the coronal magnetic field was calculated by extrapolation from the photosphere. Comparison of the observed and calculated coronal structures is carried out and some peculiarities of this comparison, related to the different phases of the solar cycle, are presented.

Radio Measurements of Coronal Magnetic Fields

1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Active Regions ◽  
High Sensitivity ◽  
Coronal Magnetic Field ◽  
Transverse Magnetic ◽  
Radio Sources ◽  
Radio Waves ◽  
Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

Gradient structures of Ni – Zn ferrites for electromagnetic radiation protection devices

2021 ◽  
Vol 5 ◽  
pp. 39-46
Author(s):  
V. V. Karanskij ◽  
◽  
S. V. Smirnov ◽  
A. S. Klimov ◽  
E. V. Savruk ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electromagnetic Radiation ◽  
Radiation Protection ◽  
Electromagnetic Compatibility ◽  
Protective Coatings ◽  
Frequency Range ◽  
Near Surface ◽  
Zn Ferrite ◽  
Absorbing Materials ◽  
Plasma Electronic

Increasing the reliability requirements for electromagnetic compatibility of electronic equipment requires the creation of protective coatings that absorb electromagnetic radiation or the development of new radio-absorbing materials. In the frequency range up to 1 GHz, radio-absorbing materials based on Ni – Zn ferrites are of the greatest interest. The absorption of electromagnetic radiation by ferrites occurs due to resonant phenomena at the level of domains and atoms. Improving the performance of ferrites is possible by modifying their surface properties. In this paper, gradient structures for electromagnetic radiation protection products are obtained by treating the surface of Ni – Zn ferrite samples with a low-energy electron beam. To generate the electron beam, a unique development was used — a forevacuum plasma electronic source that allows forming and transporting a beam with a power density of up to 105 W/cm2 under conditions of high pressure and high gas release. As a result of processing, gradient structures were found on the surface of ferrites. A theoretical analysis and experimental study of the obtained structures “non – magnetic conductor – ferrite”, characterized by an increased attenuation coefficient and a reduced reflection coefficient of electromagnetic radiation in the frequency range from 0.5 to 2.5 GHz. The possibility of obtaining near-surface layers depleted in zinc with increased electrical conductivity and reduced magnetic permeability is shown.

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