Electron-impact excitation of molybdenum from the (4d55s)a7S ground state

Abstract

Theoretical results from multi-state nonrelativistic R-matrix (close-coupling) calculations are presented for electron-impact excitation of molybdenum from the (4d55s)7S ground state. The dependence of the results on the details of the theoretical model, particularly on the structure description and the number of coupled states, is analysed. These results represent the first step in an ongoing programme to obtain atomic data for spectroscopic modelling of a molybdenum-oxide lamp displaying strong transitions of Mo I.

Relativistic R -matrix calculations for the electron-impact excitation of neutral molybdenum

“…o excitation is smaller than those presented by both [2] and [3]. However, we see good agreement in shape between our cross section and the one presented by [3].…”

“…However, we see good agreement in shape between our cross section and the one presented by [3]. These variations potentially arise due to differences in the target structures used and the specific details of the scattering calculations.…”

“…These are compared with the results of the two previous calculations in LS coupling, for which we must statistically average our fine structure results. We focus on the a [3] who carried out a nonrelativistic 67 state R-matrix calculation including only septet, quintet, and triplet terms below 7 eV.…”

“…These variations potentially arise due to differences in the target structures used and the specific details of the scattering calculations. We compare the transition rate (in LS coupling) from our atomic structure calculation (after statistically averaging the fine structure values in Table II) with the value given by [2] (after shifting the reported rates to experimental energy differences), the value given by [3], and the experimental value given by Whaling et al [18] (again, after statistically averaging the fine structure values). Our GRASP 0 structure gives an A-value of 7.12 × 10 7 s −1 compared to the experimental value of 6.49 × 10 7 s −1 , and the values of 2.01 × 10 8 s −1 and 1.62 × 10 8 s −1 reported by [2] and [3], respectively.…”

“…Small-scale calculations for neutral molybdenum in LS coupling have been carried out [2,3] using nonrelativistic R-matrix theory. However, these models are incomplete, including only 6 and 67 terms, respectively, in the scattering calculations, directly leading to inaccuracies in any work related to modeling using Mo I.…”