Abstract
To determine the direct electron-impact excitation cross sections with the optical method, one must measure all transitions out of a level, as well as the cascade into the level of interest from higher-lying energy levels. Considered here are the ten levels of the configuration of neon, whose emissions to lower levels fall within a range of 540–810 nm. This allows an investigation via a monochromator-photomultiplier tube system. Cascades into these levels from and however, emit radiation in the 740–1720-nm range, part of which is outside the limit of photomultiplier detection. We employ a Fourier-transform spectrometer to examine the near-infrared lines. We report direct electron excitation cross sections for the ten levels for electron energies up to 200 eV. In addition, we provide apparent excitation functions for the and levels. We have also observed a dependence of the optical emission cross sections on pressure, and describe this effect within the framework of the resonance radiation reabsorption model.
- Received 19 November 1999
DOI:https://doi.org/10.1103/PhysRevA.61.052708
©2000 American Physical Society