Electron excitation cross sections for the metastable and resonant levels of Ne(2p53s)

Abstract

The electron excitation cross section both for the ${}_{}{}^3{}_{}{}^{}\mathrm{P}_2^{}{}_{}{}^{}$ and ${}_{}{}^3{}_{}{}^{}\mathrm{P}_0^{}{}_{}{}^{}$ metastable levels (1$s_5$ and 1$s_3$ in Paschen’s notation) and for the mixed ${}_{}{}^3{}_{}{}^{}\mathrm{P}_1^{}{}_{}{}^{}$ and ${}_{}{}^1{}_{}{}^{}\mathrm{P}_1^{}{}_{}{}^{}$ resonant levels (1$s_4$ and 1$s_2$ in Paschen’s notation) of the 2$p^5$3s configuration of Ne have been measured. Apparent and direct excitation cross sections are reported for incident electron energies from threshold to 300 eV and are compared with results of different methods of measurements. Ground-state Ne atoms are excited by a monoenergetic electron beam to the 1s levels, and atoms in the 1s levels are pumped to the 2p levels of the 2$p^5$3p configuration by means of a cw dye laser. The laser-induced fluorescence from the 2p level is utilized to determine the electron excitation cross section for the 1s level. Methods for absolute calibration of the cross sections are given.