Measurement of the rotationally resolved total cross sections for the Cs (6D5/2) + H2 → CsH [X1 Σ+ (v, J)] + H reaction

Using a pump-probe method, the reaction of Cs (6D5/2) with H2 in a crossed heat pipe oven has been studied. The nascent rotational distributions of Cs [X1 Σ+ (υ=0, 1; J)] were determined from laser induced fluorescence (LiF) spectra. The rotational population profile was roughly consistent with a statistical distribution at the system temperature. The decay signal of time resolved fluorescence from A1 Σ+ (υ', J + 1) → X1 Σ+ (υ, J) transition was monitored. The semi log plot of the time resolved fluorescence was shown. The slope yielded the transition probability. The densities of the Cs (6D5/2) atoms excited by the pulse laser beam were evaluated directly from the laser energy loss which was absorbed by Cs atoms. The densities of CsH [X1 Σ+ (υ, J)] molecules were measured the absorption of the probe laser beam, reduced to 10 nj using neutral density filters. Using a rote equation model, reactive cross sections σ (υ, J) have been obtained. The cross sections σ (υ) are yielded by summing the individual cross sections σ (υ, J). have been obtained. The cross sections σ (υ) are yielded by summing the individual cross sections σ (υ, J). The cross sections (in units of 10-16 cm2) are (0.64 ± 0.19) for υ being 0 and (0.58 ± 0.17) for υ being 1, respectively. (authors)