Atomic excitation in strongly coupled plasmas

H. Kitamura; M.S. Murillo; J.C. Weisheit

doi:doi:10.1051/jp4:2000595

Issue		J. Phys. IV France Volume 10, Number PR5, March 2000 The 1999 International Conference on Strongly Coupled Coulomb Systems


Page(s)		Pr5-493 - Pr5-496
DOI		https://doi.org/10.1051/jp4:2000595

The 1999 International Conference on Strongly Coupled Coulomb Systems

J. Phys. IV France 10 (2000) Pr5-493-Pr5-496
DOI: 10.1051/jp4:2000595

Atomic excitation in strongly coupled plasmas

H. Kitamura^{1, 2, 3}, M.S. Murillo¹ and J.C. Weisheit^{1, 3}

¹ Applied Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545, U.S.A.
² Institute for Solid State Physics, University of Tokyo, Roppongi, Tokyo 106-8666, Japan
³ Space Physics and Astronomy Department, Rice University, Houston, TX 77005, U.S.A.

Abstract
In dense plasmas atomic excitation rates arising from scattering between atoms and surrounding plasma particles are formulated on the basis of the equations of motion for density matrices in a stochastic potential. This model enables us to treat strong transitions for which the first-order perturbation theory does not apply. Within a decorrelation approximation, which enables one to break up the higher-order correlation functions of plasma density fluctuations into the products of binary correlation functions (i.e., dynamic structure factors), the interaction is effectively summed to infinite order. This method is applied to two-level atoms in hydrogen plasmas. It is thereby demonstrated that when the plasma density is sufficiently high, low-frequency ion-density fluctuations may cause coherent atomic excitation between close lying states. Such coherent excitation cannot be described by the conventional collisional rate equations based on the first-order perturbation theory.