Search results for "electromagnetic"

A search for diffuse absorption bands in carbon-rich stars -- I. Barium and related stars

2003

The results of a search for interstellar and circumstellar absorption lines in high-resolution optical spectra of seven late-type stars are presented. All these stars are single-lined spectroscopic binaries with unseen companions, presumably white dwarfs. Some residual material indicative of recent mass transfer from an asymptotic giant branch (AGB) star might still be associated with the systems. Peculiar energy distribution and the sodium D 1 and D 2 lines give direct evidence about the material in the line of sight in some cases. Absorption features of simple carbon-bearing molecules (C 2 , CN) have been detected in most of the examined stars, confirming a carbon-rich nature of the corre…

Retrieval of sun-induced fluorescence using advanced spectral fitting methods

2015

Abstract The FLuorescence EXplorer (FLEX) satellite mission, candidate of ESA's 8th Earth Explorer program, is explicitly optimized for detecting the sun-induced fluorescence emitted by plants. It will allow consistent measurements around the O2-B (687 nm) and O2-A (760 nm) bands, related to the red and far-red fluorescence emission peaks respectively, the photochemical reflectance index, and the structural-chemical state variables of the canopy. The sun-induced fluorescence signal, overlapped to the surface reflected radiance, can be accurately retrieved by employing the powerful spectral fitting technique. In this framework, a set of fluorescence retrieval algorithms optimized for FLEX ar…

Collinear Resonance Ionization Spectroscopy of Neutron-Deficient Francium Isotopes

2013

The magnetic moments and isotope shifts of the neutron-deficient francium isotopes 202-205Fr were measured at ISOLDE-CERN with use of collinear resonance ionization spectroscopy. A production-to-detection efficiency of 1% was measured for 202Fr. The background from nonresonant and collisional ionization was maintained below one ion in 105 beam particles. Through a comparison of the measured charge radii with predictions from the spherical droplet model, it is concluded that the ground-state wave function remains spherical down to 205Fr, with a departure observed in 203Fr (N = 116). ispartof: Physical Review Letters vol:111 issue:21 pages:212501-4 ispartof: location:United States status: pub…

Nuclear orientation of radon isotopes by spin exchange optical pumping

1988

This paper reports the first demonstration of nuclear orientation of radon atoms. The method employed was spin exchange with potassium atoms polarized by optical pumping. The radon isotopes were produced at the ISOLDE isotope separator of CERN. The nuclear alignment of /sup 209/Rn and /sup 223/Rn has been measured by observation of ..gamma..-ray anisotropies and the magnetic dipole moment for /sup 209/Rn has been measured by the nuclear-magnetic-resonance method to be chemically bond..mu..chemically bond = 0.838 81(39)..mu../sub N/.

Photon and Pion Nuclear Absorption Mechanisms

1992

Using a microscopical many body approach to pion and photonuclear reactions we study the mechanisms of pion and photon absorptions with emphasis on the number of nucleons involved in the genuine absorption process.

Inductance Calculations for Circular Coils of Rectangular Cross Section and Parallel Axes Using Bessel and Struve Functions

2010

A simple method for calculating the mutual and self inductances of circular coils of rectangular cross section and parallel axes is presented. The method applies to non-coaxial as well as coaxial coils, and self inductance can be calculated by considering two identical coils which coincide in space. It is assumed that current density is homogeneous in the coil windings. The inductances are given in terms of one-dimensional integrals involving Bessel and Struve functions, and an exact solution is given for one of these integrals. The remaining terms can be evaluated numerically to great accuracy using computer packages such as Mathematica. The method is compared with other exact methods for …

LocalD=4field theory onκ-deformed Minkowski space

2000

We describe the local $D=4$ field theory on $\ensuremath{\kappa}$-deformed Minkowski space as a nonlocal relativistic field theory on standard Minkowski space-time. For simplicity the case of a $\ensuremath{\kappa}$-deformed scalar field $\ensuremath{\varphi}$ with the interaction $\ensuremath{\lambda}{\ensuremath{\varphi}}^{4}$ is considered, and the $\ensuremath{\kappa}$-deformed interaction vertex is described. It appears that the fundamental mass parameter $\ensuremath{\kappa}$ plays the role of regularizing the imaginary Pauli-Villars mass in the $\ensuremath{\kappa}$-deformed propagator.

Simulation of forces and 3-D field arising during power autotransformer fault due to electric arc in HV winding

2002

Forces and three-dimensional magnetic fields in high-voltage winding due to an internal short circuit in a power autotransformer are calculated with the computer package OPERA 3D. The considered damage was caused by an electric arc. The materialized deformation of the winding part confirms the simulation results.

Meson and isobar currents in photo absorption and scattering for deuterium

1982

Role of Polarization Mode Dispersion on Modulational Instability in Optical Fibers

2001

We introduce the theory of modulational instability (MI) of electromagnetic waves in fibers with random polarization mode dispersion. Applying a linear stability analysis and stochastic calculus, we show that the MI gain spectrum reads as the maximal eigenvalue of a constant effective matrix. In the limiting cases of small or large fluctuations, we give explicit expressions for the MI gain spectra. In the general configurations, we give the explicit form of the effective matrix and numerically compute the maximal eigenvalue. In the anomalous dispersion regime, polarization dispersion widens the unstable bandwidth. Depending on the type of variations of the birefringence parameters, polariza…