Transfer between the cesium62P1/2and62

Abstract

The cross sections of spin-orbit energy exchange between the cesium 6 2 P 1/2 ↔ 6 2 P 3/2 states induced by collisions with N 2 , H 2 , HD, D 2 , CH 4 , C 2 H 6 , CF 4 , and C 2 F 6 were obtained for pressures less than 100 Torr at room temperature by means of steady-state laser-induced fluorescence techniques. The spin-orbit energy exchange rate with N 2 , H 2 , HD, D 2 , CH 4 , C 2 H 6 , CF 4 , and C 2 F 6 , have been measured as σ 21 (6 2 P 3/2 → 6 2 P 1/2 ) = 16. 3, 34.1, 30.0, 22.7, 21.4, 65.6, 64.8, and 137Å 2 and σ 12 (6 2 P 1/2 → 6 2 P 3/2 ) = 1. 8, 4.4, 4.1, 3.0, 2.9, 13.3, 9.7, and 16.3Å 2 , respectively. Correlations of the spin-orbit transfer probabilities with rotational-energy defect and vibrational-energy defect have been shown.

Spin-orbit relaxation and quenching of cesium 72Pin mixtures of helium, methane, and ethane

“…12. Scaling of fine-structure mixing cross sections with vibrational energy defect for (•) Cs 6 2 P 3/2,1/2 [14] and (•) Cs 7 2 P (present results). Buffer gases include CH 4 , C 2 H 6 , and C 2 F 6 .…”

“…11. Scaling of the fine-structure mixing cross sections, σ 21 , with adiabaticity for He collisions with the lowest 2 P states of Cs, Rb, K, and Na and the higher excited n = 7, 8 2 P and n = 5 2 D states of Cs: (•) prior data [14][15][16] and (•) present result for Cs 7 2 P .…”

“…While the fine-structure mixing and quenching of the first excited 2 P 3/2,1/2 states in the alkali-metal atoms is well studied [9][10][11][12][13][14][15]24], the kinetic database for the higher-lying states is rather limited [9,10,15]. The rates for Cs 7 2 P 3/2,1/2 with helium and methane collision partners have previously been determined and are summarized in Table III.…”

“…Recent studies of mixing in Rb 5 2 P 3/2,1/2 and Cs 6 2 P 3/2,1/2 by molecular collision partners attribute the efficient collisional mixing to rovibrational excitation [14,15]. The splitting in Cs 7 2 P 3/2,1/2 of 181 cm −1 is more nearly resonant with the 289 cm −1 vibrational mode of ethane than the lowest, 1367 cm −1 , mode of methane, leading to an enhancement in the mixing rate.…”

“…For the case of He, that barrier structure is absent allowing the collision to proceed via long-range forces, increasing the cross section. The rates for fine-structure mixing of the lowest 2 P states in the alkali metals for collisions with rare gases increase with decreased splitting, as predicted by adiabaticity arguments [13,14]. When the splitting is large and the collision energy is low, the duration of the collision is long relative to the oscillation period and the rates are slow.…”