Excitation of carbon monoxide and nitrogen molecules by electron impact at energies below 16 eV: studies of resonances in the excitation functions of metastable and ultraviolet-emitting levels

Resonance structure in electron–N2scattering around 11.5 eV: high-resolution measurements,ab initiocalculations and line shape analyses

“…The nearly energy-independent metastable yield below the N * 2 E 3 + g threshold and around the N − 2 R 2 + g resonance is due to the excitation of lower-lying metastable levels (mainly A 3 + u and a 1 π g [10,39,41]). The dashed line in figure 13 represents a linear (almost constant) function fitted to this smooth yield.…”

“…The excitation function of the N * 2 E 3 + g state has been studied many times in the past. Here we only mention previous work carried out with high-resolution (energy width around 20 meV) [10,39,41]. Brunt et al [41] and Brunger et al [39] used similar setups involving a channel electron multiplier as the detector for the metastable levels.…”

“…Here we only mention previous work carried out with high-resolution (energy width around 20 meV) [10,39,41]. Brunt et al [41] and Brunger et al [39] used similar setups involving a channel electron multiplier as the detector for the metastable levels. In order to enhance detection of low-lying metastable levels, Newman et al [10] applied a detector with heated tantalum ribbons in conjunction with a channel electron multiplier.…”

Metastable fragment production by electron-impact dissociation of SO2

“…Contributions could be present due to metastable S, SO or 02 fragments and, as discussed later, all of these species are in fact present. The metastable detector is able to detect those metastable species with excitation energies greater than the work function of the channeltron (estimated to be about 8 eV by Brunt et al [7]). Consequently, only O(3s 5S°) metastable atoms at 9.14 eV are detected, whereas O(2p41D), O(2p41S), S(3p41D), S(3p41S), and S(4s 5S°) metastable atoms do not produce any signal.…”

“…SO(A3//) has been observed to be strongly excited following electron impact on SOz (Ajello et ai. [2] and Miller and Becker [7]). However, (2) might be favoured because of its less severe requirements for spin conservation.…”