Laser studies of near-resonant state-changing collisions of calcium (4s6s1S0) with the rare gases

摘要: State-changing collisions of Ca(4s6s ${}^{1}$${S}_{0}$) with the rare gases are studied by pulsed laser excitation and time- wavelength-resolved detection. The total depletion rates 4s6s ${}^{1}$${S}_{0}$ state different vary over a factor 10, lighter being markedly more efficient than heavier ones. Relative branching ratios to specific near-resonant, energy-transfer product states, 4p4p ${}^{1}$${D}_{2}$ (\ensuremath{\Delta}E=-29 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$), 3d4p ${}^{1}$${F}_{3}$ (\ensuremath{\Delta}E=152 ${}^{3}$${S}_{1}$ (\ensuremath{\Delta}E=216 measured for $^{3}\mathrm{He}$, $^{4}\mathrm{He}$, Ne, Xe. Transfer $^{1}\mathrm{D}_{2}$ is always major relaxation pathway. rate constant $^{3}\mathrm{S}_{1}$ production immeasurably small, implying small spin-orbit matrix element curve crossing that leads spin change. results compared simple theoretical calculations based on established models near-resonant energy transfer between states which coupled at large internuclear distance. These successfully explain dominant trends gas, attributed largely enhancement near-resonant-transfer process increasing velocity. effects wave-function mixing in isolated atom (e.g., mixing) general outcome state-changing two-electron atoms discussed. Two-electron offer numerous possibilities further testing theories transfer.