Quantum-mechanical phase interference and optical polarization in low-energy Na+Hg inelastic collisions

Cross sections for production of Hg(6³P₁) and Na(3²P) have been measured for low energy (?3 keV) Na⁺Hg collisions. An antiphase oscillatory structure in the energy dependence has been observed, and attributed to phase interference between charge-exchange and direct excitation channels. From the measurement of polarization of the Hg-resonance line, another pronounced antiphase oscillatory behaviour is found for the two cross sections for production of the magnetic sublevels, m_J=0 and m_J = ± 1, of the Hg(6³P₁) state.