The role of excited-state ionization on the effective ionization of neutral neon using non-perturbative atomic data

Abstract

With the aim of providing accurate atomic data for plasma edge temperature and density modeling with neutral neon, new non-perturbative R-Matrix with Pseudostates (RMPS) calculations are performed for both the electron-impact excitation and ionization of neutral neon. The new calculations agree well with past measurements and calculations for both electron-impact excitation and ionization. For ionization, the addition of pseudostates from to allows us to extract new cross sections and rate coefficients for all of the excited states through 2p5 5p. The new RMPS ionization calculation gives a 20% increase in the cross section for the ionization compared with previous non-perturbative calculations and shows classically-expected n4-scaled convergence for the np and nd valence shells. Ionization from these excited states contributes significantly to the effective ionization rate coefficient: a factor of three more than the ground-state ionization rate coefficient at an electron temperature of 25 eV and density of 1014 cm−3. An accurate, non-perturbative set of atomic rates, both LS- and LSJ-resolved, for neutral neon across a wide range of temperatures and densities is compiled.

The He/Ne beam diagnostic for line-ratio spectroscopy in the island divertor of Wendelstein 7-X

“…20 Ne I lines have been observed in this wavelength range. The T e , n e dependence of the line-ratios has been investigated using photon emissivity coefficients from the observed lines calculated with a Ne CRM employing new atomic rate coefficients computed by colleagues from Auburn University [16]. High Rydberg states are at the moment not included in the Ne CRM.…”