Knowledge Bank

V-V transfer rates from $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CO(v=1)$ to $\mathrm{<mrow\; data-mjx-texclass="ORD">14</mrow>}N2$, $\mathrm{<mrow\; data-mjx-texclass="ORD">15</mrow>}N2$, $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}CO$ and $O2$ have been determined versus temperature, from 100 to 700$\circ K$, using the laser fluorescence method. For the $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CO-13CO$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CO-15N2$ systems, the transfer rate decreases with temperature showing that long-range multi-polar forces have a preponderant effect on the transfer. For the less resonant systems $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CO-14N2$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CO-O2$ the rate increases with temperature from $100\circ K$ showing that repulsive forces have a dominant effect. For the two systems $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CO-14N2(\Delta \nu =-187.5cm-1)$ and $CO-15N2(\Delta \nu =-108.5cm-1)$, the effect of the energy level gap $\Delta \nu$ between the colliding partners is dramatically demonstrated; at $100\circ K$ , the ratio of these rates is as great as about 30; theoretical calculations explain these results. This set of experimental studies is a clear demonstration of the different interaction forces.