ABSTRACT
Our previous studies of dissociative recombination and vibrational excitation/de-excitation of the BeH+ ion, based on the multichannel quantum defect theory, are extended to collision energies above the dissociation threshold, taking into account the vibrational continua of the BeH+ ion and, consequently, its dissociative excitation. We have also significantly increased the number of dissociative states of 2Π, 2Σ+ and 2Δ symmetry included in our cross section calculations, generating the most excited ones by using appropriate scaling laws. Our results are suitable for modeling the kinetics of BeH+ in edge fusion plasmas for collision energies up to 12 eV.
ABSTRACT
A nonlinear time-dependent collisional-radiative model for recombining argon is presented. Reactions involving Ar(2)+ are taken into account and their influence is discussed. It is shown that Ar(2)+ may increase the time to reach the quasi-steady-state by a factor of 100. The calculation of the recombination rate coefficient at the quasi-steady-state is presented. An analytical expression is derived and compared with existing literature values. The importance of the increase of the quasi-steady-state time is illustrated by comparisons of excited levels population densities distribution measured in a fast moving plasma where the mechanical time scale is sufficiently short to provide a time-dependent chemistry in a reference frame moving with the flow. The high sensitivity of the results towards the electron number density is pointed out. Finally, the influence of the processes involving Ar(2)+ on the excitation temperature is discussed.
