ESTIMATING PLASMA TEMPERATURES FROM TRANSMISSION SPECTRA

Recent laser-produced plasma experiments have relied on spectroscopic comparisons with models to infer plasma temperatures. The models use a n experimentally determined value for the matter density as input and treat the temperature as an adjustable parameter to obtain a best fit to the experimental absorption spectrum. However, uncertainties in the ionization balance theories lead to inferred temperatures that are mo del dependent. We report results of a new approach which combines high -quality atomic data with an ionization balance obtained from systemat ic expansions of the grand canonical ensemble. The latter avoids the a d hoc cutoffs required in free energy minimization schemes and include s Coulomb corrections usually neglected in other models. Comparisons t o experimental spectra show excellent agreement.