Two- and three-body collision coefficients forXe(P13)andXe(P23)atoms and radiative lifetime of theXe2(1u)molecule

Abstract

The time dependence of the vacuum-uv emissions from xenon was studied at pressures ranging from 4 to 1000 Torr. Excitation of the atoms was provided by a low-intensity electron beam. Measurements were made at the wavelengths of the $\mathrm{Xe}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ resonance line, the 1500-Å (first) continuum, and the 1700-Å (second) continuum. Two- and three-body collision coefficients for the destruction of $\mathrm{Xe}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ atoms and a three-body coefficient for $\mathrm{Xe}\left({}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}\right)$ metastables were determined. A radiative lifetime of 99 nsec for the $1_u$ molecular state was measured at the wavelength of the second continuum. The pressure dependence of the decay constants at the three wavelengths leads to the following results: The collisional deexcitation rate for the transition $\mathrm{Xe}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ to $\mathrm{Xe}\left({}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}\right)$ is ${9.1\times 10}^3$ ${\sec }^{-1\mathrm{}}$/Torr. The three-body coefficient for $\mathrm{Xe}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ atoms is 46 ${\sec }^{-1\mathrm{}}$/${\mathrm{Torr}}^2$. The three-body destruction rate of $\mathrm{Xe}\left({}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}\right)$ metastables is 40 ${\sec }^{-1\mathrm{}}$/${\mathrm{Torr}}^2$. The estimated uncertainty in the results is ±10%.