Collisional and thermal ionization of sodium n S and n D Rydberg atoms with n = 8–20 has been studied. The experiments were performed using a two-step pulsed laser excitation in an effusive atomic beam at atom density of about 2 × 10 10 cm −3 . Molecular and atomic ions from associative, Penning and thermal ionization processes were detected. It was found that the atomic ions were created mainly due to photoionization of Rydberg atoms by photons of blackbody radiation at the ambient temperature of 300 K. Blackbody ionization rates and effective lifetimes of Rydberg states of interest were determined. The molecular ions were found to be from associative ionization in Na( nL ) + Na(3S) collisions. Rate constants of associative ionization have been measured using an original method based on relative measurements of Na + 2 and Na + ion signals.Collisional and thermal ionization of sodium n S and n D Rydberg atoms with n = 8–20 has been studied. The experiments were performed using a two-step pulsed laser excitation in an effusive atomic beam at atom density of about 2 × 10 10 cm −3 . Molecular and atomic ions from associative, Penning and thermal ionization processes were detected. It was found that the atomic ions were created mainly due to photoionization of Rydberg atoms by photons of blackbody radiation at the ambient temperature of 300 K. Blackbody ionization rates and effective lifetimes of Rydberg states of interest were determined. The molecular ions were found to be from associative ionization in Na( nL ) + Na(3S) collisions. Rate constants of associative ionization have been measured using an original method based on relative measurements of Na + 2 and Na + ion signals.

arXiv:physics/0501088Journal of Physics B Atomic Molecular and Optical PhysicsJan 6, 200523 citations

Ionization of sodium and rubidium nS , nP , and nD Rydberg atoms by blackbody radiation

Ilya I. Beterov, Denis B. Tretyakov, I. I. Ryabtsev +2 more

Results of theoretical calculations of ionization rates of Rb and Na Rydberg atoms by blackbody radiation (BBR) are presented. Calculations have been performed for $nS$ , $nP$ , and $nD$ states of Na and Rb, which are commonly used in a variety of experiments, at principal quantum numbers $n=8--65$ and at three ambient temperatures of 77, 300, and $600\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ . A peculiarity of our calculations is that we take into account the contributions of BBR-induced redistribution of population between Rydberg states prior to photoionization and field ionization by extraction electric field pulses. The obtained results show that these phenomena affect both the magnitude of measured ionization rates and shapes of their dependences on $n$ . The calculated ionization rates are compared with the results of our earlier measurements of BBR-induced ionization rates of Na $nS$ and $nD$ Rydberg states with $n=8--20$ at $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ . A good agreement for all states except $nS$ with $n>15$ is observed. We also present the useful analytical formulas for the quick estimation of BBR ionization rates of Rydberg atoms.Results of theoretical calculations of ionization rates of Rb and Na Rydberg atoms by blackbody radiation (BBR) are presented. Calculations have been performed for $nS$, $nP$, and $nD$ states of Na and Rb, which are commonly used in a variety of experiments, at principal quantum numbers $n=8--65$ and at three ambient temperatures of 77, 300, and $600\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. A peculiarity of our calculations is that we take into account the contributions of BBR-induced redistribution of population between Rydberg states prior to photoionization and field ionization by extraction electric field pulses. The obtained results show that these phenomena affect both the magnitude of measured ionization rates and shapes of their dependences on $n$. The calculated ionization rates are compared with the results of our earlier measurements of BBR-induced ionization rates of Na $nS$ and $nD$ Rydberg states with $n=8--20$ at $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. A good agreement for all states except $nS$ with $n>15$ is observed. We also present the useful analytical formulas for the quick estimation of BBR ionization rates of Rydberg atoms.

arXiv:physics/0702192Physical Review AMay 30, 200747 citations

Population Redistribution of Rydberg Stark States of Na Induced by Blackbody Radiation.

Enrique J. Galvez, C. W. MacGregor, F. De Zela +1 more

APSMay 1, 19960 citations

Ionization experiments involving Na Rydberg atoms

M. Allegrini, F. Fuso, F. Giammanco +2 more

pigJan 1, 19950 citations

Results of theoretical calculations of ionization rates of Rb and Na Rydberg atoms by blackbody radiation (BBR) are presented. Calculations have been performed for

nS

nP

, and

nD

states of Na and Rb, which are commonly used in a variety of experiments, at principal quantum numbers

n=8--65

and at three ambient temperatures of 77, 300, and

600\phantom{\rule{0.3em}{0ex}}\mathrm{K}

. A peculiarity of our calculations is that we take into account the contributions of BBR-induced redistribution of population between Rydberg states prior to photoionization and field ionization by extraction electric field pulses. The obtained results show that these phenomena affect both the magnitude of measured ionization rates and shapes of their dependences on

n

. The calculated ionization rates are compared with the results of our earlier measurements of BBR-induced ionization rates of Na

nS

and

nD

Rydberg states with

n=8--20

300\phantom{\rule{0.3em}{0ex}}\mathrm{K}

. A good agreement for all states except

nS

with

n>15

is observed. We also present the useful analytical formulas for the quick estimation of BBR ionization rates of Rydberg atoms.