Elastic and excitation cross sections for electron - nitrous oxide collisions

Abstract

In this work, we present a theoretical study of elastic and inelastic electron - collisions in the low and intermediate incident energy range. More specifically, we report differential and integral cross sections for the elastic scattering in the 5 to 80 eV range as well as the excitation cross sections for the transitions leading to the lowest and states in the 10 to 100 eV range. The Born-closure Schwinger variational method was applied for the elastic scatterings whereas the distorted-wave method was used to study the electron impact excitation processes. The calculations were carried out using the fixed-nuclear static-exchange approximation at the equilibrium geometry of the ground-state . The comparison between the calculated results and the available experimental data in the literature is encouraging. .

Elastic and rotational excitation cross sections for electron–nitrous oxide collisions

“…Moreover, a second small resonance feature at around 8 eV is also seen in our calculated ICS, in accordance with the SEP studies of Sarpal et al 18 and Winstead and McKoy 21. An analysis of the calculated partial contributions from the 2 Σ, 2 Π, and 2 Δ symmetries to the ICS (not shown) reveals that the resonance at around 8 eV is of 2 Σ symmetry and corresponds to that located at 13 eV, predicted by Michelin et al 17 and Sarpal et al 18 using the SE level of approximation. The shift of about 5 eV to lower energies is caused by the introduction of V cp in our calculation.…”

“…At 3 eV, our calculation reproduces successfully the broad maximum at scattering angles around 50–60°. This feature was not seen in the previous calculated DCS using the SE 17, 19 and SEP 20, 21 approximations. Winstead and McKoy suspected that the qualitative disagreement between their calculated DCS and the experimental data could be due to the neglect of the vibrational degrees of freedom in their study.…”

“…In Figures 1 and 2 we show our calculated DCS (rotationally summed) for elastic electron–N 2 O scattering in the 3–30‐eV range along with some available experimental data 10, 11, 15, 16. The previous calculated DCS using the Born‐closure Schwinger variational method within the SE approximation 17 along with the calculated results of Morgan et al 20 and Winstead and McKoy 21 are also shown for comparison. At 3 eV, our calculation reproduces successfully the broad maximum at scattering angles around 50–60°.…”

“… The DCS for elastic e − − N 2 O scattering at (a) 3 eV and (b) 10 eV. Full curve indicates rotationally summed results; short dashed line, theoretical results of Morgan et al 20; dashed line, calculated results of Michelin et al 17; long‐dashed line, calculated results of Winstead and McKoy 21; full squares, experimental data of Marinković et al 10; full circles, experimental data of the SU group 16; open squares, experimental data of the ANU group 16; open circles, experimental data of Johnstone and Newell 11. …”

“…Therefore, it is not surprising that in the past two decades, several experimental studies on electron–N 2 O scattering were reported in the literature, including grand total (elastic + inelastic) cross‐section (TCS) measurements 7–9, elastic differential cross‐sections (DCS) 10, 11 vibrationally inelastic DCS 12–16, and electronic excitation cross‐sections 10. Also on the theoretical side, low‐energy elastic collisions between electrons and N 2 O have been the subject of several recent investigations both at the static‐exchange (SE) 17–19 and/or static‐exchange‐polarization (SEP) levels of approximation 18, 20, 21.…”