THE POLARIZATION OF ALKALIATOM D-LINE EMMISSION THE CASE OF AXIAL RECOIL EXCITATION

Author Institution:The complete and exact calculation of the observable polarization of alkali d-line emission, in the case of axial–recoil excitation, is presented and discussed. First, the formalism developed allows the differentiation of different symmetries and different angular momentum coupling schemes for the quasimolecular parent state. Second, the theory of Percival and Seaton is adapted to allow the computation of the effect of hyperfine precessional dephasing of the initial atomic state on the Zeeman Radiation Pattern of the final emission. Third, from scattering experiments performed in our laboratory we are able for the first time to introduce the effect of the distrubution of axes of quantization for the particular case of the excitation of rubidium in crossed beams with $N_{2}$. The dipole radiation distribution and natural isotope abudance effects are included in the final polorization fraction. The exact results are tabulated for sample calculations; nuclear spin I=3/2 (Na, K, Rb) and I=5/2 (Rb). And the second order nuclear quadrupole effects are demonstrated to be of less importance than accurate values of the relative lifetimes. Polarizations computed with this method are compared with recent measurements and calculations for rare gas alkali-ion scattering emission. The method is also used to discuss recently measured anisotropies in resonance enhanced photoionization electron distributions and photo-dissociation hot atom recoil