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Abstract

The merits of a previous theoretical treatment of redistribution are recalled and examined on the basis of new results derived from this formalism. The approach makes use of projected resolvants in Liouville space and implies, by the presence of the atom-radiation interaction potential in the collision operator, a natural way of including the interdependence of radiative and collisional events. One of the cases considered is the redistribution of weak radiation by three-level atoms, including both elastic and inelastic collisions with proper account for repopulation; a further case involves redistribution in the Lyman-alpha line of hydrogen. In all cases considered, the domain of validity extends from the line centre to the far wings. In contrast to many common treatments of redistribution, results imply fluorescence spectra which are everywhere positive. This is a consequence of the fact that radiative events during a collision are treated in a consistent way. Apart from being more accurate, the results also have a simpler structure. This is particularly evident for the redistribution function of Lyman-alpha whose compact form should be optimal for use in model calculations of the solar chromosphere, for example.

Additional information

Authors: VOSLAMBER D, CEA, Département de Recherches sur la Fusion Contrôlée, CEN Cadarache, Saint-Paul-lez-Durance (FR)
Bibliographic Reference: Paper presented: 11th International Conference on Spectral Line Shapes, Carry-le-Rouet (FR)
Availability: Text not available
Record Number: 199310089 / Last updated on: 1994-11-29
Category: PUBLICATION
Original language: en
Available languages: en