The collisional behaviour of the spin orbit states of the lead atom, Pb(63P1,2), studied by time‐resolved attenuation of atomic resonance radiation

Abstract

AbstractA kinetic study of lead atoms in the spin orbit states, Pb(63P1) and Pb Pb(63P2), 0.969 and 1.320 eV, respectively, above the 63P0 ground state, has been carried out by atomic absorption spectroscopy. The electronically excited lead atoms were generated by the pulsed irradiation of lead tetraethyl and monitored photoelectrically by time‐resolved attenuation of resonance radiation. The decay of the two atomic states has been studied in the presence of He, Ar, H2, D2, N2, O2, CO, NO, CO2, N2O, CH4, C2H4, C2H2 CF4, SF6, and PbEt4, and rate constants for the collisional quenching by these gases are reported. The resulting data are compared with those for the deactivation of other atomic spin orbit states of comparable energy. In general, the higher energy state, Pb(63P2), is found to be deactivated more rapidly. It would appear that the magnitude of the electronic energy to be transferred on collision governs the rates of quenching, at least where a weak interaction potential is involved, and that for most gases, deactivation of Pb(63P2) proceeds via Pb(63P1).