| This article is major in that experimental investigation of mechanisms by irradiating a Cs+H2 mixture with laser induce and optical absorption technique, the reaction cross sections of the different exited states of Cs atom with gass were mesured and evaluated. Accordingly, the relative reactivity with H2 for studied atom'levels can be obtained by compared with each other.(1) Cs(6S) was irradiated by two-photo in two-photo absorption in a glass fluorescence cell with pulses of 886 nm radiation, populating 6D3/2 state, and there are direct fluorescence of 6D3/2â†'6P as well as transferred fluorescence of 6D5/2â†'6P in atomic fluorescence. At the different densities of H2 molecules and He atoms, we have measured the relative time-integrated intensities of the component by analysis of three-state rate equation model, the cross sections of fine structure for 6D3/2 wasσ= (55±13)×10-15 and (16±13)×10-15 cm2 for H2 and He, respectively. The quenching rate coefficient for the 6D5/2 and H2, He was also determined. The quenching rate coefficient of 6D5/2 state and H2 is larger than that of 6D5/2 state and He, and the former is total of reaction and nonreactive rate coefficient. Experimental results showed that the nonreactive energy transfer rate coefficient is [6.3×10-10 cm3s-1], hence we estimate the cross section (2.0±0.8)×10-16 cm2 for reactive process of 6D5/2 and H2. Using the dependence on the pressure of H2(or He)of the integrated fluorescence monitored at the 6D5/2â†'6P3/2 transition the cross section (4.0±1.6)×10-16cm2 for Cs(6D3/2)+H2â†'CsH+H is obtained. Thus, the relative reactivity with H2 is an order Cs(6D3/2)>Cs(6D5/2).(2) Pure potassium vapor was irradiated by two-photo absorption in a glass fluorescence cell populating K2(1Λg) stats, and cross sections for (1Λg)-(3Λg) transfer have been studied using methods of molecular fluorescence. The collision cross section (2.7±1.1)×10-15 cm2 has been obtained for K2(1Λg) + H2â†'K2(3Λg) + H2 during the experiments with K-H2 mixture, in which the cell temperature was kept at 553 K constantly, the density of K was 5*1015 cm-3 and the pressure was varied between 40 and 400 Pa. The quenching cross sections is (6.8±2.7)×10-15 cm2 for K2(1Λg) + H2â†'states out of K2(3Λg) + H2. |
PDF Full Text Request