Collisional mixing and quenching cross sections of Cs 6²P levels with methane, ethane, and propane

Abstract

Mixing cross sections of Cs between the 62P1/2 and 62P3/2 levels and quenching cross sections from these levels to the ground state 62S1/2 were measured, with methane, ethane, and propane as collision partners. We excited Cs to the 6P3/2 level with a tunable nanosecond pulse laser and measured the fluorescence at the 62P1/2 level. The measured mixing cross sections with methane, ethane, and propane were (1.39 ± 0.16), (5.67 ± 0.85), and (7.91 ± 0.93)×10−15 cm2, respectively, and the statistically averaged quenching cross sections were (1.5 ± 0.25), (10 ± 2.0), and (25 ± 5.3)×10−18 cm2, respectively. The quenching cross section of Cs-propane is reported for the first time.

Analytical model of a diode-pumped cesium laser for investigation of upper-state mixing and quenching reactions

“…However, there are surprisingly few reports on the collisional mixing reaction cross sections of Cs and these hydrocarbons, as well as the quenching reaction cross sections associated with the collisions. Therefore, Endo et al measured and reported a total of six reaction cross sections for the mixing and quenching of Cs with methane, ethane, and propane [14]. The results for methane were comparable to previous high-precision measurements [15], while the quenching cross section for propane was reported for the first time.…”

“…The mixing and quenching reaction cross sections are the main trend determinants. In the present calculations, these have been set to our measured values [14]. The validity of the measured cross sections was confirmed by the fact that the numerical simulation based on them effectively reproduced the experimental results.…”

“…Using Eq. ( 20) and the fact that k Q1 and k Q2 are represented by a single constant k QAV in equilibrium [14], we obtain the following:…”

“…where σ M ij and σ Q i0 are the mixing and quenching reaction cross sections, respectively [14], and v rel is the relative velocity of the colliding partners expressed as follows:…”