Collisional-radiative modeling projects using convergent close-coupling collision data

The development of the molecular convergent close-coupling (MCCC) method has enabled large-scale convergence studies to be performed for molecular targets for the first time. Over the last decade we have been applying this technology to the electron-H₂ scattering system, with the long-term goal of producing a complete collision data set for application in collisional-radiative models. Previously, the majority of available data were either from small close-coupling calculations valid only at low energies, or semi-classical calculations valid only at high energies. There was also little vibrationally- and rotationally-resolved data available.

Motivated by fusion and astrophysical applications, we have produced cross sections numbering in the hundreds of thousands for electrons scattering on H₂ and its five isotopologues, considering rovibrational levels in the first 20 electronic states. These data have allowed detailed collisional-radiative models for low-temperature hydrogen plasmas to be constructed for the first time. In this talk, we provide an update on our collaborations with researchers who are using MCCC cross sections in plasma modeling applications, primarily in the studies of tokamak divertor plasmas and cosmic-ray propagation in molecular clouds. We will also present new results for proton-H₂ collisions, calculated using a newly-developed semi-classical implementation of the MCCC method.