An experimental concept to measure opacities under solar-relevant conditions

Abstract

Recent solar abundance models (Asplund 2009) use a significantly lower abundance for C, N, O compared to models used roughly a decade ago. Although the models used now are much more sophisticated than before, a discrepancy still exists between the abundances in the models and the abundances determined by helioseismic measurements. Agreement can be obtained by ad hoc adjustments to the opacity of high-Z (Z > 2) elements ranging from a few percent in the solar interior to as much as 30 just below the convection zone (CZ). Although many of the opacity models are thought to agree within a few percent, a recent element-by-element study (Blancard 2012) indicates a larger disagreement between models for certain elements. Experimental opacity measurements for these elements in the regimes of interest will provide valuable information to help resolve these discrepancies. We will present an experimental platform designed to measure the opacity of C, N, and O and discuss the achievable parameter regime. We will also briefly discuss how this platform can be extended to include other high-Z elements.