The Opacity Project: R-Matrix Calculations of Opacities (RMOP)

The R-matrix methodology is extended to complete calculations of astrophysical and laboratory plasma opacities. The aim is to solve outstanding problems such as the solar interior opacity problem to reconcile new chemical abundances of common volatile elements C, N, O and Ne that are up to 50% lower than previously determined. In addition to complex atomic radiative processes using the Breit-Pauli R-Matrix (BPRM) method, a new theoretical and computational method has been developed for the heretofore unsolved problem of plasma broadening of intrinsic autoionizing resonances computed in ab initio close coupling calculations. Extrinsic broadending mechanisms such as collisional, thermal (Doppler), and electric microfields (Stark) are included, as well as due to core-excitations and free-free transitions. Resutls are presented for Fe XVII, an important contributor to opacity at the base of the solar convection zone. Details of RMOP calculations for other iron ions are presented the poster on the Iron Project by Nahar et al. at this meeting.