K-alpha Emission Spectra from Non-Equilibrium Ionizing Plasmas

Verne L. Jacobs, V. Decaux, P. Beiersdorfer

Naval Research Laboratory, Code 6390
4555 Overlook Avenue, S. W.
Washington, D. C. 20375
jacobs@dave.nrl.navy.mil

K-alpha X-ray emission spectra from highly charged Fe ions have been theoretically predicted using a detailed and systematic spectral model. Account has been taken of the fundamental atomic radiative-emission processes associated with inner-shell electron collisional excitation and ionization, as well as dielectronic recombination. Particular emphasis has been directed at extreme non-equilibrium or transient-ionization conditions, which can occur in astrophysical and tokamak plasmas. Good agreement has been found in comparisons with spectral observations on the EBIT-II electron beam ion trap at the Lawrence Livermore National Laboratory. We have identified spectral features that can serve as diagnostics of the electron density, the line-formation mechanism, and the charge-state distribution.

This work has been supported by NASA, ONR, and DOE.