Home  About us  Contact
 

Magnetic Field Magnitude (magnetic + field_magnitude)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

Low magnetic fields behavior of photon echo in LuLiF4:Er3+

LASER PHYSICS LETTERS, Issue 9 2006
V. N. Lisin
Abstract It is reported about the first observation and studying of the photon echo in LuLiF4:Er3+. The energy transition is 4I15/2 , 4F9/2 (, = 6536 Å). The density of ErF3 is 0.025 wt%. The operation temperature is 1.9 K. Measurements were spent at low (up to 1200 Oe) and even zero external magnetic fields. It was studied a behavior of the photon echo intensity versus the magnetic field magnitude and direction about the crystal axis C and versus the laser pulse separation t12. It was observed an exponential growth and then, after some plateau, an exponential decreasing of the photon echo intensity as a function of magnetic field with increasing of the magnetic field from zero value. The parameters describing the exponential growth and decreasing are not depended on direction of magnetic field. Value of a magnetic field at which the echo intensity accepts the maximum, and quantity of this maximum decrease with increased the pulse separation t12 and the angle , between the magnetic field and crystal axis. The echo intensity exponentially decreases with increased , . The parameter describing the exponential decreasing is not depended on the magnitude of the field. The echo intensity as a function of pulse separation shows exponential decay. The phase relaxation time is depended on the magnitude and direction of the magnetic field. T2 is equal to 202 ± 16 ns at zero magnetic field. Phenomenological formula is suggested, which qualitatively presents the mentioned dependencies. Polarization properties of the backward photon echo in this crystal are studied also. (© 2006 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

PVLAS experiment: some astrophysical consequences

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2007
Yu. N. Gnedin
ABSTRACT The birefringent effects of photon,pseudo-scalar boson (Goldstone) particle mixing in intergalactic magnetic field are calculated for cosmological objects. We use the recent results of PVLAS collaboration that reported recently the observation of a rotation of the polarization plane of light propagating through a transverse static magnetic field. Such result was interpreted as arising due to conversion of photon into pseudo-scalar with coupling strength ga,, 4 × 10,6 GeV,1. This result contradicts to data of stellar evolution that excluded standard axion model and seems to claim existence of supersymmetry (SUSY) pseudo-scalars. We estimate the intergalactic magnetic field magnitude as ,10,16 G based on Hatsemekers et al. observations of extreme-scale alignments of quasar polarization vectors. We analysed some additional results of astronomical observations that could be explained by axion interpretation of the PVLAS data: a sharp steepening of the quasi-stellar object (QSO) continuum shortward of ,1100 Å, observed circular polarization of active galactic nuclei (AGNs) and QSOs, discrepancy between observed intrinsic polarization of stars in the Local Bubble and stellar spectral classification. The observed polarization of stars in the Local Bubble cannot be explained by interstellar origin. [source]

Magnetohydrodynamic mixer of an electrolyte solution

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2004
Svetlana Gorobets
Abstract Mixing process was investigated as a function of metal element size, external magnetic field magnitude and distance from metal cylinder surface. Investigation results have shown an application of magnetic field is possible instrument for electrolyte flow parameter change. Magnetohydrodynamic mixer of an electrolytes solution was proposed on investigation results base. The advantages of proposed device are simple construction and absence energy consumption. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Influence of dynamic structure on the microstructure formation of a steel surface in the electrolyte in a steady magnetic field

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2004
Svetlana Gorobets
Abstract The periodic microfabrication effect of metal element surfaces in an electrolyte solution in an external steady magnetic field was investigated. Authors have shown that corrosion velocity and periodic microstructure formation on the metal element surface can be controlled by magnetic field application. Geometric configuration of periodic microstructure depends on metal element characteristics, electrolyte solution, treatment time, magnetic field magnitude and other parameters. Investigation results have shown possibility of magnetic field influence on hydrodynamic conditions and metal surface structure under its etching in the nitric acid solution. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]