Kinetic and spectral descriptions of polarized atomic radiative emission from plasmas

A reduced-density-matrix description has been developed for the investigation of polarized radiative emission during single-photon transitions from bound and autoionizing states of ionized atomic systems in the presence of a general arrangement of static (or quasi-static) electric and magnetic fields. Particular emphasis has been given to excitation of the atomic states by electrons with an anisotropic velocity distribution, which can be produced in an electron-ion beam experiment or in a non-equilibrium plasma environment. It is desirable to consider the coherent excitation of a particular subspace of the atomic bound or autoionizing states, which can occur as a result of sufficiently intense electromagnetic interactions. A general expression for the matrix elements of the detected-photon density operator provides a unified framework for the analysis of the spectral intensity, angular distribution, and polarization of the Stark-Zeeman patterns. From a unified development of time-domain (equation-of-motion) and frequency-domain (resolvent-operator) formulations of the reduced-density-matrix approach, the non-equilibrium atomic-state kinetics and the homogeneous spectral-line shapes are self-consistently described.