Temperature dependence of rotational relaxation of methane in the 2n3 vibrational state by self- and nitrogen-collisions and comparison with line broadening measurements.

International audienc

Temperature dependence of rotational relaxation of methane by self- and nitrogen- collisions in the 100-300 K temperature range

International audienc

Le méthane et ses applications en planétologie Expériences pompe-sonde résolues en temps dans CH4 : relaxation collisionnelle et spectroscopie

National audienc

Calculation of (100)↔(001)(100)\leftrightarrow(001) Coriolis-Assisted Transfer Rates for O3_{3} – N2_{2} and O3_{3} – O3_{3} Collisions

A kinetic model, taking into account the rovibrational state-to-state energy transfers within the first vibrational dyad of ozone, has been applied to describe the (100) $\longleftrightarrow$ (001) Coriolis-assisted intermode transfer occurring upon O$_{3}$ – N$_{2}$ and O$_{3}$ – O$_{3}$ collisions. The state-to-state rate coefficients have been calculated by a semi-classical method based on multipolar and atom-atom interaction potentials. The temporal evolutions of the populations of the $|vJK_{\rm a}K_{\rm c}>$ ($v=(100)$ or (001)) levels, calculated by our model, show a strong dependence on the value of the $K_{\rm a}$ number. The predicted temperature dependence of the energy transfers from (100) levels towards (001) levels, after pumping into a (100) level, agrees well with the available results obtained from double- resonance experiments in the 200-300 K temperature range