Title :
The effect of doubly excited states on emission line ratios and absolute powers used in spectroscopic diagnostics
Author :
Ouart, N.D. ; Apruzese, J.P. ; Giuliani, J.L. ; Dasgupta, A. ; Clark, R.W.
Author_Institution :
NRC/NRL Postdoctoral Associate, Naval Research Laboratory, 4555 Overlook Ave., SW Washington DC 20375, USA
Abstract :
Summary form only given. Emission line ratios have been used as an effective diagnostic for the determination of the plasma parameters. However, the treatment of doubly excited states in such models can affect the ionization dynamics which can subsequently alter the emission line ratios and absolute powers used for plasma diagnostics. Prior models have also assumed that the electron energy distribution function (EEDF) is Maxwellian, but previous experiments have measured electron beams and Ka line emission. The Ka emission was produced as a result of the electron beams ionizing an inner-shell electron from lower ionization stages. The presence of such hot electrons suggests that the EEDF is simply not Maxwellian and requires a modification in the high energy tail. These high energy electrons can also produce doubly excited ions with inner-shell vacancies, alter the ionization kinetics, and furthermore impact line ratios used to determine the plasma parameters. The effect of doubly excited states on emission line ratios and absolute powers from a multi-zone non-LTE copper pinch model with radiation transport using coupling coefficients will be presented and discussed in light of experimental data.
Keywords :
Distribution functions; Electron beams; Ionization; Laboratories; Plasma diagnostics;
Conference_Titel :
Plasma Science (ICOPS), 2012 Abstracts IEEE International Conference on
Conference_Location :
Edinburgh
Print_ISBN :
978-1-4577-2127-4
Electronic_ISBN :
0730-9244
DOI :
10.1109/PLASMA.2012.6383502