EVIDENCE FOR A "CHEMICAL" WELL BETWEEN Xe AND Cl ATOMS

An investigation of the interaction potential between ground state Xe and $Cl(^{2}P_{3/2})$ atoms has been carried out experimentally by crossing two supersonic atomic beams and measuring the relative differential cross section $\\left ( \\frac {d\\sigma} {d\\Omega} \\right )$ of $^{35}Cl$ as a function of laboratory angle. The $Ar + Xe$ system has also been studied for comparison. The usual heavier rare gas scattering structures, namely, rainbow and supernumerary rainbows were resolved in the $Ar + Xe$ data. However, the $Cl + Xe$ data displays a new oscillatory structure qualitatively different from the rare gas pair. Analysis consists of assuming a potential, by an analytic form, and numerically integrating Schr\\"{o}dinger’s equation to obtain scattering phase shifts, and hence $ \\frac {d\\sigma} {d\\Omega} $. The potential is found by fitting the experimental points with the calculated values. In this way, evidence for a shallow $(< 1 kcal/mole)$ chemical well for ClXe approximately 1 {\\AA} inside the ArXe van der Waals’ well location has been found. This well coexists with an outer region, probably of van der Waals’ character, giving the potential an unusual shape.