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Photoionization Cross-section (photoionization + cross-section)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

Hydrostatic pressure effects on the donor impurity-related photoionization cross-section in cylindrical-shaped GaAs/GaAlAs quantum well wires

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 14 2004
J. D. Correa
Abstract Using a variational method the binding energy has been calculated for a shallow donor impurity and the donor-related photoionization cross-section in 1D and 0D GaAs low-dimensional systems. The dependence on the binding energy and the photoionization cross-section for a hydrogenic donor impurity in the finite potential model are discussed and the results are presented as a function of the radius, polarization of the photon, applied hydrostatic pressure, and photon energy. The calculations for the pressure effects are performed both in the direct and indirect GaAs gap regime. Calculations are presented for an on-axis (on-center) impurity in the wire (in the dot). (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Radiative transitions of the helium atom in highly magnetized neutron star atmospheres

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2008
Z. Medin
ABSTRACT Recent observations of thermally emitting isolated neutron stars revealed spectral features that could be interpreted as radiative transitions of He in a magnetized neutron star atmosphere. We present Hartree,Fock calculations of the polarization-dependent photoionization cross-sections of the He atom in strong magnetic fields ranging from 1012 to 1014 G. Convenient fitting formulae for the cross-sections are given along with the related oscillator strengths for various bound,bound transitions. The effects of finite nucleus mass on the radiative absorption cross-sections are examined using perturbation theory. [source]