Radiative lifetime measurements of the singlet-G states of H2 and the 4p35p and 4d5D0 states of neutral oxygen atom

The present work reports measurements of the mean radiative lifetime for the G1μ/sub g/ + (v' = 0,1,2,3) and l1II/sub g/ + (v' = 0) Rydberg states and the K1μ/sub g/ + (v' = 0,1,2),M1μ/sub g/ + (v' = 0) and N1μ/sub g/ + (v' - 1,2) doubly excited of the H2 molecule. In particular, the resulting radiative transitions G1μ/sub g/ + (v' = 0,1,2,3) → B1μ/sub u/ + (v'' = 0,1,3,5,7), l1II/sub g/ + (v' = 0) → B1μ/sub u/ + (v'' = 0), K1μ/sub g/ + (v' = 0,1,2) → B1μ/sub u/ + (v'' = 0,1), M1μ/sub g/ + (v' = 0) → B1μ/sub u/ + (v'' = 0) and N1μ/sub g/ + (v' = 1,2) → B1μ/sub u/ + (v'' = 0,2) are observed using time-resolved techniques. Radiative lifetime measurements in the range approx. 21 to 70 ns are obtained at 50 eV incident electron energy and approx. 30 mtorr H2 gas pressure. In addition, H2 - H2* quenching rate data are obtained for several rovibronic levels of the singlet-g states over the pressure range approx. 10 to 400 mtorr. In addition, time-resolved techniques are also used to observe the 4p5P → 3s5S0, 4p3P → 3s3S0, and 4d5D0 → 3p3P multiplet transitions of the Ol spectrum occurring at lambda = 3947 A, lambda = 4368 A, and lambda = 6157 A, respectively. The excited atomic states are produced through dissociative-excitation of O2 target gas by a pulsed electron beam of approx. 0.5 and 2 μs pulse width and 100 eV incident energy. The mean radiative lifetimes of the 4p5P, 4p3P and 4d5D0 multiplets are obtained from analysis of the resulting radiative decay over the pressure range approx. 20 - 100 mtorr, and are reported as 194 ns, 161 ns, and 95 ns, respectively. The corresponding collisional deactivation cross sections for the multiplets are also obtained from the lifetime versus pressure measurements and are reported as 3.2 x 10-15 cm2, 7.7 x 10-15 cm2, and 1.6 x 10-15 cm2, respectively