Intensity Of Electromagnetic Radiation Research Articles

Effect of inductive and capacitive coupling on the current–voltage characteristic and electromagnetic radiation from a system of Josephson junctions

We have studied the current–voltage characteristic of a system of long Josephson junctions taking into account the inductive and capacitive coupling. The dependence of the average time derivative of the phase difference on the bias current and spatiotemporal dependences of the phase difference and magnetic field in each junction are considered. The possibility of branching of the current–voltage characteristic in the region of zero field step, which is associated with different numbers of fluxons in individual Josephson junctions, is demonstrated. The current–voltage characteristic of the system of Josephson junctions is compared with the case of a single junction, and it is shown that the observed branching is due to coupling between the junctions. The intensity of electromagnetic radiation associated with motion of fluxons is calculated, and the effect of coupling between junctions on the radiation power is analyzed.

Electromagnetic radiation from linearly and nonlinearly oscillating charge drops

It has been shown that analytic calculations of the intensity of electromagnetic radiation from an oscillating charged drop in the approximation linear in the oscillation amplitude (small parameter is on the order of 0.1) give only the quadrupole component of the total radiation. The dipole component can only be obtained in calculations using higher-order approximations. Nevertheless, the intensity of the dipole radiation turns out to be substantially higher (by 14–15 orders of magnitude). This is because the decomposition of radiation from a system of charges into multipole components (differing even in the rates of decrease in the potential with the distance) is carried out using the expansion in a substantially smaller parameter, viz., the ratio of the size of the emitting system (in our case, a drop of radius ~10 μm) to the distance to the point of observation in the wave zone of the emission of radiation (emitted wavelength) of 100–1000 m. As a result, this second small parameter is on the order of 10–7 to 10–8. On the other hand, in accordance with the field theory, the ratio of intensities of quadrupole and dipole radiations is proportional to the squared ratio of the hydrodynamic velocity of the oscillating surface of a charged drop to the velocity of propagation of an electromagnetic signal in vacuum (velocity of light), which yields a ratio of 10–14 to 10–15.

Electromagnetic emission of a strongly charged oscillating droplet

Analytical expressions for electric field in the vicinity of an oscillating strongly charged droplet of nonviscous conducting liquid and intensity of electromagnetic radiation are derived in the linear approximation with respect to perturbation amplitude of the droplet surface. Order-of-magnitude estimations of the radiation intensity are presented. The intensity of electromagnetic radiation of a ball lightning that can be simulated using a charged droplet is not related to the surface oscillations.

Radiation of electromagnetic waves of an oscillating charged drop

The analytical expressions for the intensity of the electric field are found in the vicinity of an oscillating charged drop of a nonviscous electrically conducting fluid, as well as the intensity of electromagnetic radiation induced by it in a linear approximation of the perturbation amplitude. Estimates in order of size are carried out.

Intensity of electromagnetic energy radiation by a quiescent ferromagnetic spherical particle placed in a permanent magnetic field

The classical problem of calculating the energy of electromagnetic energy radiated from a ferromagnetic particle is solved for the case when the vector of spontaneous magnetization M of the ferromagnet differs from that of external permanent magnetic field H0. The dependence of electromagnetic radiation intensity on the product κR (where κ = ω0/c is the wavevector, R is the radius of the particle, and ω0 = γeH0 is the precession frequency of transverse component M⊥ of the magnetization (M = M⊥, Mz)) is derived.

An EMR-based method for evaluating the effect of water jet cutting on pressure relief

Water jet cutting (WJC) can play a good role in coal pressure relief. Its effect is commonly evaluated using a traditional method based on debris-drilling amount. However, this evaluating result is unsatisfactory due to great artificial interference. Based on previous experimental researches on the relationship of electromagnetic radiation (EMR) to stress during the failure of coal rock under loading, we analyze the EMR response to seam pressure relief using WJC from the angle of stress relief and carried out experiments to verify that EMR response could be used to evaluate the effect of WJC on coalbed pressure relief at Xinzhi and Yuejin Coal Mines, China, with self-developed KBD5 EMR monitor. The research showed that after WJC, the intensity and changes of EMR reflect not only the stress level from which the cut coal seam suffered but also the processes of stress transfer and evolution, thus proving that EMR can be used to evaluate the effect of WJC for coal mass pressure relief. Moreover, the experiments also showed that if without borehole collapse after WJC, multiple WJC in the same borehole can be performed to monitor EMR signals and when two adjacent signal curves keep at the same level and without obvious decline, WJC could fully release pressure in coal mass.

Efficient Evaluation of EM Radiation Associated With Information Leakage From Cryptographic Devices

This paper presents an efficient map generation technique for evaluating the intensity of electromagnetic (EM) radiation associated with information leakage for cryptographic devices at the printed circuit board level. First, we investigate the relation between the intensity of the overall EM radiation and the intensity of EM information leakage on a cryptographic device. For this purpose, we prepare a map of the magnetic field on the device by using an EM scanning system, after which we perform correlation electromagnetic analysis (CEMA) at all measurement points on the device, including points above the cryptographic module. The examined device is a standard evaluation board for cryptographic modules (side-channel attack standard evaluation board), where a cryptographic circuit is implemented on one of the field-programmable gate arrays on the board. With this experiment, we demonstrate that both an EM radiation map and an information leakage map can be generated simultaneously by scanning the board only once. We also confirm that the generated map is in good agreement with the corresponding map obtained from exhaustive CEMAs.

UVSiPM: A light detector instrument based on a SiPM sensor working in single photon counting

UVSiPM is a light detector designed to measure the intensity of electromagnetic radiation in the 320–900 nm wavelength range. It has been developed in the framework of the ASTRI project whose main goal is the design and construction of an end-to-end Small Size class Telescope prototype for the Cherenkov Telescope Array. The UVSiPM instrument is composed by a multipixel Silicon Photo-Multiplier detector unit coupled to an electronic chain working in single photon counting mode with 10 nanosecond double pulse resolution, and by a disk emulator interface card for computer connection. The detector unit of UVSiPM is of the same kind as the ones forming the camera at the focal plane of the ASTRI prototype. Eventually, the UVSiPM instrument can be equipped with a collimator to regulate its angular aperture. UVSiPM, with its peculiar characteristics, will permit to perform several measurements both in lab and on field, allowing the absolute calibration of the ASTRI prototype.

A HISTORY OF RADIO ASTRONOMY POLARISATION MEASUREMENTS

While intensity of electromagnetic radiation (radio, infrared, light, or X-ray) gives us primary information about the distribution of the baryonic matter in the Universe, polarisation is a parameter that enables us to investigate many additional details. Polarisation at radio frequencies gives us details of emission processes since the non-thermal synchrotron process dominates at low radio frequencies in emission regions. In addition, polarised radio sources can be used as probes of the intervening interstellar medium through which the radio waves are propagated. Faraday rotation effects are observed and in conjunction with known thermal emission can be used to determine magnetic fields. The Zeeman effect, a direct method of determining magnetic fields, depends on the observation of the circular polarisation components of a spectral line. In this paper I describe the early polarisation observations of radio sources, but in addition I follow the developments through to the present day.

Effect of Voltage Pattern on Intensity of Electromagnetic Emission during Electric Flame-Off Process of Ball Bonding Machine

Electromagnetic interference (EMI) can degrade device performance, particularly a sensitive device such as magnetic recording heads. A high applied voltage generates a high electric field in order to break the electrical air gap during a gold ball bonding process. This work, for the first time, investigates the influence of high voltage pattern of a gold ball bond machine on both electric field and magnetic field as an electromagnetic wave by monitoring an intensity of electromagnetic interference. The investigation was carried out by simulation of a live gold ball bond machine operation by using a finite integral technique. The simulation results reveal that the voltage pattern plays an important role in the intensity of electromagnetic radiation (EMR). In conclusion, an ideal voltage pulse of 2 kV and 4 kV generates the highest EMR detected by a monopole antenna. The induced voltage occuring at the antenna reflecting the intensity of EMI blasting was as high as 33.39 V and 71.36 V, respectively. Smoothening the voltage pattern by incrasing the rise time of voltage to 100 ns only, the induced voltage at the antenna was reduced down to 99.90% and 99.92% compairing with the case of an ideal voltage pulse for the peak EFO voltage of 2 kV and 4kV respectively. This concludes the importance of the voltage pattern during a free air ball forming process; hence lowering the risk of the highly sensitive deivce to be damaged by EMI blasting.

New Media Maps as ‘Contact Zones’: Subjective Cartography and the Latent Aesthetics of the City-Text

New Media Maps as ‘Contact Zones’: Subjective Cartography and the Latent Aesthetics of the City-Text

Sustainable urban development and geophysics

Sustainable urban development and geophysics

Interaction of electromagnetic radiation with silicate spheroidal aerosol particles

Quantitative interpretation of remote sensing measurements of aerosols requires knowledge of the interaction of small particles with electromagnetic radiation. Many natural particles are known to have nonspherical shapes, and scattering properties of such particles can differ both quantitatively and qualitatively from those of “equivalent” spheres, thereby significantly affecting the results of remote sensing retrievals. In this paper, we calculate the distribution of intensity of electromagnetic radiation inside prolate spheroidal silicate particles and compared them with analogous results for spherical particles.

A Study of Electromagnetic Radiation of Corona Discharge Near 500-Kv Electric Installations

Data on the spectral composition and intensity of electromagnetic radiation of corona discharge are obtained in an experimental study performed on the outdoor switchgear of the Shagol 500-kV substation of the Chelyabinsk Enterprise of Trunk Transmission Grids and under a 500-kV Shagol – Kozyrevo overhead transmission line. The electromagnetic environment on the territory of the 500-kV outdoor switchgear is shown to be determined by narrow-band radiations (harmonics of the frequency of electric supply) and wide-band radiations due to corona discharges of high-voltage sources. This means that the personnel experience the action of a commercial-frequency electric field and electromagnetic radiation of a quite wide range, which is not allowed for by the existing guidelines. It is recommended to continue the study in cooperation with medical institutions in order to create guidelines that would allow for the joint action of commercial-frequency electric field and electromagnetic radiation and for the voltage in the line, the current load, the meteorological situation, and other factors.

Structural Regularities and Interference Effects in the Course of Relaxation Processes in Boron Oxide in the Glass Transition Range

The structural changes in vitreous boron oxide in the course of relaxation processes after an increase or a decrease in the temperature are studied by the small-angle X-ray scattering (SAXS) technique. The differences observed in the SAXS and light scattering intensities and in the behavior of their temperature dependences, which are obtained upon heating of vitreous boron oxide samples at a constant rate, are explained in terms of interference effects. The conclusion is drawn that the interference effects are due to a uniform distribution of inhomogeneity regions formed in the course of relaxation processes. These effects bring about a change in the intensity of electromagnetic radiation scattering in the range of small angles and, in particular, a change in the light scattering intensity. The interference effects that change the angular distribution of the intensity of electromagnetic radiation scattering can be observed after either a decrease or an increase in the temperature of samples. This implies that the regularity in the distribution of inhomogeneity regions is a general feature of the microinhomogeneous structure arising from relaxation processes.

TOPOLOGICAL INTENSITY SHIFTS OF ELECTROMAGNETIC FIELD IN LOBACHEVSKIAN SPACES. Olbers Paradox Solved, Deep Space Communication, and the New Electromagnetic Method of Gravitational Wave Detection - Abstract

The major new result is the behavior of the intensity of electromagnetic radiation in Lobachevskian (hyperbolic) spaces. Equation (2) expresses change in intensity vs. space curvature and distance. Non existence of Olbers paradox in a Lobachevskian universe is shown. A new electromagnetic method for detection of gravitational waves is proposed. Explanation of observed perioditicy in redshifts is given. Problems of deep space communications are discussed.

Electromagnetic radiation produced by linear oscillations of a charged drop

A dispersion equation is derived for the capillary oscillations of a charged drop of an ideal incompressible liquid travelling in an ideal incompressible ambient allowing for the energy lost via emission of electromagnetic radiation. The intensity of electromagnetic radiation emitted by a single drop and a storm cloud has been estimated.

Transition radiation from electrons: Application to thin film and superlattice analysis

The transition radiation from nonrelativistic electrons moving in periodical nanostructures is discussed in view of its application to surface and interface analysis and thickness measurements. The spectrum of this radiation is shown to deliver information on the investigated sample that is similar to that provided by conventional x-ray reflectivity methods. An analytical expression for the intensity of electromagnetic radiation from the electrons passing through the periodical multilayers has been derived. Numerical examples of radiation spectra are given for some typical sample models, and general conditions for the observation of these spectra with a background of bremsstrahlung are discussed.

Electrical Generation of Spontaneous Optical Emission in Electrically Modulated Two-Dimensional Electron Gases at Low-Temperatures

A detailed theoretical study is presented for spontaneous optical emission from a two-dimensional electron gas (2DEG) in the presence of a unidirectional spatially periodic modulation at low temperatures. The momentum- and energy-balance equations for electron–photon interactions in the device system are solved self-consistently using the Boltzmann equation, from which we can obtain the frequency and the intensity of the electromagnetic radiation generated. The results obtained indicate that: (1) in an electrically modulated 2DEG at low temperatures, a strong electromagnetic radiation emission up to W/cm2 can be generated by applying a small d.c. electric field; (2) the radiation emission is generated indirectly in the occupied subbands through electronic transitions around the Fermi level; (3) the frequency of the radiation generated is at about 0.1 THz; (4) in the low frequency regime, spontaneous multiphoton emissions can be observed; and (5) this type of optical emission depends strongly on the sample parameters such as the electron density of the 2DEG and the modulation length.

Experimental study of the features of VLF, MF, HF and VHF electromagnetic radiation accompanying rock fracture

In order to investigate the physical mechanism of seismo-electromagnetic signals, many scholars from China and other countries have carried out laboratory and field experiments of rock samples by loading them up to fracture in recent ten-odd years. In each of these experiments, the phenomenon of electromagnetic radiation was observed during the process of rock sample fracture. However, the experimental results can not explain the non-synchronous electromagnetic radiation in actual observation records. In these records, some stations displayed anomalies but some others did not, and the signals of different frequency bands observed by the same station did not occur simultaneously. This has brought about many difficulties to the application of electromagnetic radiation in earthquake prediction. The experimental result of this paper can explain the phenomenon of non-synchronous electromagnetic radiation. In the experiment of this paper, rock samples are uniaxially compressed up to fracture. The antennas of different frequency bands are installed two meters away from the rock sample in different directions. The electromagnetic signals during the whole process of rock sample fracture are recorded synchronously by a 14-channel tape recorder. The experimental results are as follows: (1) signals of the four frequency bands: VLF, MF, HF and VHF, are all recorded during the main fracturing process of rock samples, but signals of different frequencies may somtimes occur non-synchronously; (2) the intensity of electromagnetic radiation is the highest at the moment when the main fracture occurs, but signals in different directions are of different intensities. The above results are consistent with the non-synchronous electromagnetic radiation observed in real earthquakes. It seems possible to predict the orientation of future seismic source by the electromagnetic method of the LF or VLF frequency bands.