Knowledge Bank

The interaction potentials foe the systems F + Ne Kr, Xe and Cl + Xe have been investigated from the measurements of differential scattering cross sections $[\sigma (\theta )]$ at various collision energies by crossing two supersonic atomic beams, F (C1) atoms were produced by thermal dissociation in a resistively heated nickel (graphite) oven using rare gases as carriers. In addition to $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}P3/2$ ground state, the halogen atom beam contains an appreciable amount of spin-orbit excited state, $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}P1/2$. From the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}P3/2+1SO(2P1/2+1SO)$ asymptote emerge $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi 1/2$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi 3/2(2\Pi 1/2)$ states. Data analysis proceeds by assuming an analytic form for the potentials $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi 1/2(X12),2\Pi 3/2(I32),2\Pi 1/2(II12)$ (where $VI32(R)+ESO=VII12(R),ESO$ is the spin-orbit atomic splitting) and using the central field approximation for scattering from each"" state to derive a total $\sigma (\theta ):\sigma tot(\theta )=\sigma X12(\theta )+\sigma I32(\theta )+a\sigma II12(\theta )$. The factor a takes into account the fraction of the spin-orbit excited state $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}P1/2$ produced in the oven. The $I(32)$ and $II(12)$ potentials are assumed to be very near the corresponding rare gas pairs and the greatest sensitivity in fitting the $\sigma (\theta )$ comes from the $VX12$ (R) potential. Agreement between calculated and experimental $\sigma (\theta )$ is good. Where spectroscopic data exist, for F-Xe, and Cl-Xe, the $VX12(R)$ agreement is excellent. Quantum mechanical close coupling calculations are now underway for comparison, and to obtain absolute integral cross sections for elastic and inelastic channels.