Description
Interpreting the spectra from magnetically-confined/astrophysical plasmas involves generating synthetic spectra from collisional-radiative models at the required densities and temperatures. These models are underpinned by accurate atomic and collisional rates, ideally employing the same atomic structure. For example, within an astrophysical context, near-neutral ion stages of nickel (Ni) are required for non-local thermodynamic equilibrium of the nebular phase of supernovae. Additionally, synthetic spectra generated for neutral nickel will be used for line identification for a compact toroidal hybrid experiment at Auburn University.
Collisional rates for near neutral targets, benefit from non-perturbative approaches such as the Dirac R-matrix (DARC) or Dirac R-Matrix with Pseudo-states approach (DRMPS). Initially, relativistic atomic orbitals are calculated within a Multi-Configuration-Dirac-Fock (MCDF) approximation employing a modified version of the General Relativistic Atomic Structure Package (Grasp0). Where available, Energy levels and A-values were compared with experimental values and in general found good agreement. Subsequently, a relativistic electron-impact excitation was then performed (DARC) producing collision strengths that have been Maxwellian convolved for implementation within collisional-radiative codes. Some of our results
shall be presented.