TY - JOUR

T1 - Absorption and emission line profile coefficients of multilevel atoms-IV. Velocity-averaged generalized redistribution functions for three-photon processes

AU - Hubeny, I.

AU - Oxenius, J.

PY - 1987/4

Y1 - 1987/4

N2 - The atomic generalized redistribution functions for three-photon processes, derived in the previous paper of this series, are formulated in terms of linear superpositions of newly introduced auxiliary functions qI-qVI, thus extending the traditional formalism of redistribution functions for two-photon processes. The corresponding velocity-averaged laboratory functions QI-QVI of these auxiliary functions are derived in both their angle-dependent and angle-averaged forms. Since the expressions found for QI-QVI are quite complicated, the so-called disentangled approximation is employed that uses the representative values of the generalized redistribution function at an orthogonal triad of photon directions rather than the angle-averaged function itself. This approximation yields relatively simple expressions which can be used in radiative transfer calculations.

AB - The atomic generalized redistribution functions for three-photon processes, derived in the previous paper of this series, are formulated in terms of linear superpositions of newly introduced auxiliary functions qI-qVI, thus extending the traditional formalism of redistribution functions for two-photon processes. The corresponding velocity-averaged laboratory functions QI-QVI of these auxiliary functions are derived in both their angle-dependent and angle-averaged forms. Since the expressions found for QI-QVI are quite complicated, the so-called disentangled approximation is employed that uses the representative values of the generalized redistribution function at an orthogonal triad of photon directions rather than the angle-averaged function itself. This approximation yields relatively simple expressions which can be used in radiative transfer calculations.

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U2 - 10.1016/0022-4073(87)90008-2

DO - 10.1016/0022-4073(87)90008-2

M3 - Article

AN - SCOPUS:45949129187

VL - 37

SP - 397

EP - 406

JO - Journal of Quantitative Spectroscopy and Radiative Transfer

JF - Journal of Quantitative Spectroscopy and Radiative Transfer

SN - 0022-4073

IS - 4

ER -