https://doi.org/10.1007/s100530170179
Singlet-triplet excitation ratios in Ne III, Ar III and N II under ion impact
1
Institut de Physique Nucléaire, Atomique et de Spectroscopie,
Université de Liège, Sart Tilman B 15, 4000 Liège, Belgium
2
Experimental physik III/NB3, Ruhr-Universität Bochum, 44780 Bochum, Germany
Corresponding author: a traebert@ep3.ruhr-uni-bochum.de
Received:
17
November
2000
Revised:
31
January
2001
Published online: 15 July 2001
Peculiar properties of ion-atom collision systems,
in particular deviations from statistical
populations of singlet and triplet levels, can be
studied by optical spectroscopy. We have
extended earlier studies by VUV spectroscopy of a
number of collision systems at various
collision energies in the 0.01-MeV/nucleon to
1-MeV/nucleon range, involving H
, H+, He+,
He2+, Ne+, Ar+, and N as projectiles and Ne, Ar,
and N2 as target gases. Statistically
significant deviations of the relative intensities
of singlet and triplet lines from simple ratios are
observed in the displaced terms of the valence shell
of Ne III, corroborating and extending earlier work.
For Ar III, the energy dependences of singlet-to-triplet
excitation ratios are very different for different projectiles.
For N II, in contrast, all observed line ratios are
practically independent of the projectile energy.
PACS: 34.50.Fa – Electronic excitation and ionization of atoms (including beam-foil excitation and ionization) / 34.10.+x – General theories and models of atomic and molecular collisions and interactions (including statistical theories, transition state, stochastic and trajectory models, etc.) / 32.30.Jc – Visible and ultraviolet spectra
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001
