Collisional and thermal ionization of sodium Rydberg atoms III. Experiment and theory fornS andnD states withn= 8–20 in crossed atomic beams

Abstract

The results of experimental and theoretical studies of collisional ionization of Na Rydberg atoms in nS and nD (n = 8-20) states are presented. Molecular and atomic ions from associative ionization and photoionization by blackbody radiation were detected after pulsed laser excitation of Rydberg states in crossed Na atomic beams. An original method of determination of associative ionization rate constants based on the measurement of ratios of molecular and atomic ion signals was used, which did not require the determination of absolute number density of Rydberg atoms. The measured rate constants of associative ionization of Rydberg atoms in collisions with ground-state Na atoms are compared with the results of our earlier single-beam experiment and theoretical calculations. It is shown that the stochastic ionization model, which describes the collisional ionization of Rydberg atoms in terms of chaotic migration of highly excited electron induced by the motion of the colliding nuclei, yields a significantly better agreement with the experimental results than the earlier Duman-Shmatov-Mihajlov-Janev model.

The influence of -mixing processes in collisions on atoms’ populations in weakly ionized helium plasmas

“…Namely, these processes are well studied experimentally and theoretically and it was found that there is very good agreement between experimental and theoretical results [17][18][19][20][21][22][23][24][25][26].…”

“…The resonant mechanism has been successfully applied to chemi-ionization processes in alkali Rydberg's atoms collisions with their parents' ground state [16], and further for alkali atoms' collisions [17][18][19][20][21][22][23][24][25][26]. In the case of hydrogen and helium atoms, the resonant mechanism was used to analyze the chemi-ionization and their inverse chemi-recombination processes [27][28][29][30][31][32][33].…”

Two photon resonant excitation of Copper–Rydberg levels

“…The alkali metal atoms of groups I and II have been studied extensively where 2, 3, and multi-photon absorption have been reported as well as theoretical investigations [14][15][16][17][18][19][20][21][22]. These pioneering studies not only access high lying Rydberg states, but the multi-photon excitation results in high angular momentum Rydberg final states which selection rules yield inaccessible by single photon absorption.…”

Effect of finite detection efficiency on the observation of the dipole-dipole interaction of a few Rydberg atoms

“…An experimental setup was the same as we used in our recent experiments on collisional and BBR ionization of sodium Rydberg atoms [34]. The Na effusive atomic beam with the 650 K temperature (v 0 ≈ 680 m/s) was formed in a vacuum chamber with the 5×10 −7 Torr background pressure.…”