Opacity Structure of Glass Ablator in ICF Target Design

Abstract

Opacity is dependent on the radiation temperature, material temperature and density of the material. The collisional ionization and the excitation rate can have direct effect on the temperature and the electron density of plasma. The plasma density can be determined by measurements of Stark-broadened K-shell spectral lines. Because Silicon may be used as dopant in the ablator of ignition target, the knowledge of their opacities is very important. The purpose of this work is to obtain a more detailed structure of opacity in regards with broadening effects in the form of Voigt profile. For this aim the opacity frequency dependency and the mean opacity of mixed plasmas are calculated under local thermodynamic equilibrium conditions. The final results show that the Stark-broadened line shape is dependent on the density. Also it is shown that the resonance peak and spectrum broadening of opacity spectrum of mixed plasma such as the $\hbox {SiO}_2$-plasma is larger than a single atom plasma such as Silicon, Si. Eventually these results can be used in the design of fuel pellets in Inertial Confinement Fusion.