Code development for opacity database

摘要

In connection with Stockpile Stewardship and designing meaningful experiments for the forthcoming NIF laser, the need of establishing a useful opacity database for single elements has become acute. An up- to-date opacity database has several requirements; it has to provide the best state of the art opacities and also it has to be in such a format that it lends itself to an easy calculation of mixture opacities. Ir view of the anticipated large scale calculations, the second requirement is absolutely essential. After some lengthy considerations the decision was made to establish a new single element opacity database at LLNL. This database will have the temperature and the averaged free electron density as an input grid. The underlying physical thought behind the idea of using the free electron density as an input variable is that under that condition the mixing of single element components is dynamically correct. We investigate the above assertion by presenting calculations for cooper and beryllium. Cooper and beryllium present an interesting study case because a copper-beryllium mixture is an alternate to the brominated plastic in NIF ICF capsule designs. In Section 11 we present some rudimentary theoretical formulas and in Section III we analyze computational results, as given by the new HOPE opacity code.