decayed by this moment can occur and, therefore, optical transitions from them can
be observed. Where can settlement come from? From metastable states. What did
the authors of [24, 25] observe? It was found that for target species, M = He, Ar,
N 2 , only two rotational levels of only two vibrational levels of two states of the NO
Fig. 5.6 Schematic representation of an experimental setup for studying collision-induced
non-adiabatic transitions. Above, the collision partner is located in the collision chamber; below, a
collision partner is formed in a molecular beam (see [26]). N, nozzle, F, filament, SK, skimmer, M,
monochromator, PM, photomultiplier tube; IF, interference filter; PN—pulse nozzle forming a
colliding partner molecular beam; FIG—pulse ionization manometer (Reproduced from R.
Bachmann, Ch. Ottinger, A.F. Vilesov, J. Chem. Phys. 96, 5151–5164 (1992). https://doi.org/10.
1063/1.462756 with the permission of AIP Publishing)
Fig. 5.7 Potential energy
curves of the NO lower states
[24] (Reproduced from Ch.
Ottinger, A.F. Vilesov,
J. Chem. Phys. 100, 1805–
1814 (1994) https://doi.org/
10.1063/1.466533 with the
permission of AIP Publishing)
172
5 Energy Transfer in Collisions