Open AccessElectron‐impact rotational excitation of linear molecular ions
Author(s) -
Faure Alexandre,
Tennyson Jonathan
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04480.x
Subject(s) - physics , excitation , atomic physics , ion , electron ionization , electron , dipole , electron excitation , polyatomic ion , atomic electron transition , range (aeronautics) , ionization , quantum mechanics , spectral line , materials science , composite material
Molecular R ‐matrix calculations are performed to give rotational excitation rates for electron collisions with linear molecular ions. Results are presented for CO + , HCO + , NO + and H 2 + up to electron temperatures of 10 000 K. De‐excitation rates and critical electron densities are also given. It is shown that the widely used Coulomb–Born approximation is valid for Δj=1 transitions when the molecular ion has a dipole greater than about 2D, but otherwise is not reliable for studying electron‐impact rotational excitation. In particular, transitions with Δj>1 are found to have appreciable rates and are found to be entirely dominated by short‐range effects.