Time dependence of the vacuum-uv emissions from neon, and energy transfers to the resonance statesNe(P11)andNe(P13)in helium-neon mixtures

Time-resolved studies of the vacuum-uv emissions from neon and helium-neon mixtures were made using a single-photon counting technique. Excitation of the atoms was provided by a pulsed beam of 250-keV electrons. Measurements in neon were carried out at the wavelengths of the resonance states $\mathrm{Ne}\left({}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$, and $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$. Collision coefficients for the destruction of $\mathrm{Ne}\left({}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$, $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$, and $\mathrm{Ne}\left({}_{}{}^2{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ atoms in neon were determined. The two-body collision coefficient for deexcitation of $\mathrm{Ne}\left({}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ atoms to the $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ state is 5.5 × ${10}^4$ ${\sec }^{-1\mathrm{}}$/Torr. Atoms in the $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ level undergo two-and three-body collisions with neon ground-state atoms. The deexcitation rate for the transition $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ to $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}\right)$ is 1.80 × ${10}^3$ ${\sec }^{-1\mathrm{}}$/Torr. The three-body collision coefficient for $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ is 5.0 ${\sec }^{-1\mathrm{}}$/${\mathrm{Torr}}^2$. Metastable $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}\right)$ atoms are collisionally excited to the $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ state at the rate 160 ${\sec }^{-1\mathrm{}}$/Torr, and they are destroyed in three-body collisions with rate coefficient 0.60 ${\sec }^{-1\mathrm{}}$/${\mathrm{Torr}}^2$. The two-body deexcitation frequency for $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ and two- and three-body collision coefficients for $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}\right)$ are in agreement with the results of Phelps. Studies of the emissions from He-Ne mixtures were performed at relatively high helium pressures of 200 and 400 Torr, respectively. At each helium pressure controlled amounts of neon impurity were added. Time-resolved measurements were made at the wavelengths of the $\mathrm{He}\left(2\mathrm{}{}_{}{}^1{}_{}{}^{}S\right)$ metastable, the helium continuum emissions, and at the wavelengths of $\mathrm{Ne}\left({}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ and $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$. The decay constants for $\mathrm{He}\left(2\mathrm{}{}_{}{}^1{}_{}{}^{}S\right)$ and $\mathrm{Ne}\left({}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ are shown to be consistent with resonant excitation transfer from $\mathrm{He}\left(2\mathrm{}{}_{}{}^1{}_{}{}^{}S\right)$ to the $\mathrm{Ne}\left(3\mathrm{}{s}_2\right)$ laser level (Paschen notation). The pressure dependence of the emissions from $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ in helium is governed primarily by collisional deexcitation to the metastable $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}\right)$ state. The two-body collision coefficient for the destruction of $\mathrm{Ne}\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)$ atoms by helium is 8.3 × ${10}^3$ ${\sec }^{-1\mathrm{}}$/Torr.