CRITICAL REVIEW OF N, N ⁺ , N ⁺ ₂ , N ⁺⁺ , And N ⁺⁺ ₂ MAIN PRODUCTION PROCESSES AND REACTIONS OF RELEVANCE TO TITAN'S ATMOSPHERE

Ionization cross-sections for positron collisions with N2

“…The close correspondence between the two sets below 20 eV, and the slight excess of the latter in comparison with the present results above this energy, might imply a crosssection of the order of 0.2 × 10 −16 cm 2 for N + production (the threshold for which is at 24.29 eV), a factor of approximately 3.5 lower than than the peak value for electrons [13]. The main dissociative pathway for N + production in single ionization is via the N + 2 (C 2 Σ + u ) state, the creation of which requires the removal of an innervalence electron [14]. The suppression of the latter type of reactions by a positron has been previously observed (e.g.…”

Bond-Forming Chemistry in the Gas-Phase Reactions of Atomic and Molecular Dications and Trications

“…However, such rate data are vital for modelers trying to understand the role of dication reactions in energized media, such as planetary ionospheres. 38,48,49 Guided ion beam (GIB) experiments address these shortcomings. A typical arrangement for such an experiment is shown in Figure 4.…”

“…61,62 A review of the chemistry and kinetics of N 2 2+ and N 2+ has recently been published, aiming to identify the best current data that can be incorporated into atmospheric and ionospheric models. 48 Undoubtedly, the coverage of the dicationic chemistry in this article is not exhaustive, but there is at least now a compendium of data to which modelers can refer. Collision complexes with different lifetimes have been identified, by crossed-beam scattering, in the reaction of CHCl 2+ with D 2 to form CHDCl + + D + .…”

What characterizes planetary space weather?

“…The picture is very different as soon as carbon atoms can react with hydrogen, both coming from the dissociation of different molecules. The case of Titan, where methane and carbon dioxide co-exist in large quantities reveals a very complex chemistry with about a thousand of each type of reactions (Dutuit et al 2013). This complexity makes it impossible (with current computer facilities) to include a detailed chemical description of the atmosphere in a global atmospheric model solving also the production through photo-absorption or electron impacts and the time-dependent continuity equation.…”