Spectroscopic diagnosis of long-scale-length exploding-foil plasma in the presence of an intense radiation field

摘要

An effective technique for measuring the local electron temperature and density of a laser-produced plasma involves analysis of the emission and/or a absorption spectrum from an impurity dopant. Spatial resolution can be obtained by depositing the impurity in the form of a small microdot on or slightly below the surface of the foil, so that it remains spatially confined while the plasma evolves. However, when an intense high-energy radiation field is present, the ionization balance, level population, and resulting spectrum produced by the impurity may be significantly perturbed. We are currently using several computer models to study the effects of such a radiation field for experimental conditions that could be obtained using the Nova laser facility, and are concentrating on the behavior of line intensity ratios that are typically used for density and temperature diagnosis. The goal of the work presented in this paper is to design an experiment that can be conducted on Nova to determine the feasibility of spectroscopic diagnosis when an intense high-energy radiation field is present.