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Title: Rayleigh scattering from excited states of atoms and ions

Abstract

Elastic photon scattering from the ground state and various excited states of carbon atoms and ions has been investigated, using the S-matrix formalism, for incident photon energies ranging from 100 eV to 10 keV, contrasting the results obtained for different configurations. The excited states considered include hollow-atom states, where one or more inner shells are completely vacated. Ionic cases are considered as a limit of excitation. Results demonstrate how cross sections for different excited states group together according to shared properties of the configurations, such as the number of K electrons. Cross sections may exhibit deep dips below the K edge, depending on the occupation of the subshells corresponding to the strongest transitions. Scattering from excited states can have significantly larger cross sections than scattering from the ground state, particularly just below the K resonance region, and therefore it needs to be considered in situations where there is a large population of these excited states. Results are interpreted in terms of form-factor arguments and the qualitative behavior of individual subshell amplitudes. The angular dependence of cross sections can be understood in terms of angle-dependent form factors and anomalous scattering factors, taken to be angle independent. Cases are identified for whichmore » excited-state total integrated cross sections are much larger than the corresponding cross sections for scattering from the ground state. Our main results use an averaging over magnetic substates at the level of the amplitude, exact only for fully filled subshells, but generally appropriate for the carbon case considered, which simplifies the discussion and explains most of the general features. We also present results for a hollow lithium atom with and without this approximation to illustrate the differences that can arise in certain circumstances. (c) 2000 The American Physical Society.« less

Authors:
 [1];  [1];  [2];  [3];  [4]
  1. Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)
  2. Physics and Space Technology, Lawrence Livermore National Laboratory, Livermore, California 94551-0808 (United States)
  3. Department of Physics, Bose Institute, Calcutta 700009, West Bengal, (India)
  4. University Science Instrumentation Centre, North Bengal University, Darjeeling 734430, (India)
Publication Date:
OSTI Identifier:
20216405
Resource Type:
Journal Article
Journal Name:
Physical Review. A
Additional Journal Information:
Journal Volume: 61; Journal Issue: 5; Other Information: PBD: May 2000; Journal ID: ISSN 1050-2947
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; EXCITED STATES; RAYLEIGH SCATTERING; PHOTON-ATOM COLLISIONS; CARBON; CARBON IONS; S MATRIX; EV RANGE 100-1000; KEV RANGE 01-10; LITHIUM; EXPERIMENTAL DATA; THEORETICAL DATA

Citation Formats

Carney, J. P. J., Pratt, R. H., Kissel, Lynn, Roy, S. C., and Sen Gupta, S. K. Rayleigh scattering from excited states of atoms and ions. United States: N. p., 2000. Web. doi:10.1103/PhysRevA.61.052714.
Carney, J. P. J., Pratt, R. H., Kissel, Lynn, Roy, S. C., & Sen Gupta, S. K. Rayleigh scattering from excited states of atoms and ions. United States. doi:10.1103/PhysRevA.61.052714.
Carney, J. P. J., Pratt, R. H., Kissel, Lynn, Roy, S. C., and Sen Gupta, S. K. Mon . "Rayleigh scattering from excited states of atoms and ions". United States. doi:10.1103/PhysRevA.61.052714.
@article{osti_20216405,
title = {Rayleigh scattering from excited states of atoms and ions},
author = {Carney, J. P. J. and Pratt, R. H. and Kissel, Lynn and Roy, S. C. and Sen Gupta, S. K.},
abstractNote = {Elastic photon scattering from the ground state and various excited states of carbon atoms and ions has been investigated, using the S-matrix formalism, for incident photon energies ranging from 100 eV to 10 keV, contrasting the results obtained for different configurations. The excited states considered include hollow-atom states, where one or more inner shells are completely vacated. Ionic cases are considered as a limit of excitation. Results demonstrate how cross sections for different excited states group together according to shared properties of the configurations, such as the number of K electrons. Cross sections may exhibit deep dips below the K edge, depending on the occupation of the subshells corresponding to the strongest transitions. Scattering from excited states can have significantly larger cross sections than scattering from the ground state, particularly just below the K resonance region, and therefore it needs to be considered in situations where there is a large population of these excited states. Results are interpreted in terms of form-factor arguments and the qualitative behavior of individual subshell amplitudes. The angular dependence of cross sections can be understood in terms of angle-dependent form factors and anomalous scattering factors, taken to be angle independent. Cases are identified for which excited-state total integrated cross sections are much larger than the corresponding cross sections for scattering from the ground state. Our main results use an averaging over magnetic substates at the level of the amplitude, exact only for fully filled subshells, but generally appropriate for the carbon case considered, which simplifies the discussion and explains most of the general features. We also present results for a hollow lithium atom with and without this approximation to illustrate the differences that can arise in certain circumstances. (c) 2000 The American Physical Society.},
doi = {10.1103/PhysRevA.61.052714},
journal = {Physical Review. A},
issn = {1050-2947},
number = 5,
volume = 61,
place = {United States},
year = {2000},
month = {5}
}