We discuss the systematics of energy levels of high-angular-momentum Rydberg states of alkali-metal atoms, and show that they are well described by a quantum-defect model. Polarization of the core electrons by the valence electron is shown to be the dominant contribution to the quantum defect. As an example, recently observed splittings between the $l=3,4,\mathrm{and} 5$ levels in various Rydberg states of sodium are analyzed to yield values for the core polarizabilities. Effective values of the dipole and quadrupole polarizability of 1.0015(15) and 0.48(15) a.u., respectively, are obtained. Implications for the precise determination of the structure of highly excited Rydberg states in alkali atoms are discussed.We discuss the systematics of energy levels of high-angular-momentum Rydberg states of alkali-metal atoms, and show that they are well described by a quantum-defect model. Polarization of the core electrons by the valence electron is shown to be the dominant contribution to the quantum defect. As an example, recently observed splittings between the $l=3,4,\mathrm{and} 5$ levels in various Rydberg states of sodium are analyzed to yield values for the core polarizabilities. Effective values of the dipole and quadrupole polarizability of 1.0015(15) and 0.48(15) a.u., respectively, are obtained. Implications for the precise determination of the structure of highly excited Rydberg states in alkali atoms are discussed.

Physical Review ANov 1, 1976190 citations

Collisional angular momentum mixing in Rydberg states of sodium

Thomas F. Gallagher, S. A. Edelstein, R. M. Hill

Springer eBooksApr 6, 20085 citations

Collisional broadening of Rydberg atoms perturbed by ground-state sodium atoms

V. M. Borodin, I. I. Fabrikant, Andrey K. Kazansky

Zeitschrift für Physik D Atoms Molecules and ClustersMar 1, 19932 citations

Electron Impact Ionization of Sodium Rydberg Atoms below 2 eV

Kannadaguli Nagesha, Keith B. MacAdam

We have observed electron impact ionization of highly excited sodium Rydberg atoms in $ns$ and $nd$ states, $n=35--51$ , below $E=2\text{ }\text{ }\mathrm{e}\mathrm{V}$ electron kinetic energy with energy resolution 0.25 eV. Measured absolute cross sections near 0 eV range from ${\ensuremath{\sigma}}_{35d}\ensuremath{\approx}7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ to ${\ensuremath{\sigma}}_{50d}\ensuremath{\approx}4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}\text{ }\text{ }{\mathrm{c}\mathrm{m}}^{2}$. The energy dependence is consistent with that of widely used binary encounter approximation cross sections, and ${\ensuremath{\sigma}}_{n}$ follows a power law in $n$ . The measured cross sections are 14 to 24 times larger than theoretically predicted values. This enhancement may signal the effect of large polarizabilities of high Rydberg states not yet accounted for in ionization theories.We have observed electron impact ionization of highly excited sodium Rydberg atoms in $ns$ and $nd$ states, $n=35--51$, below $E=2\text{ }\text{ }\mathrm{e}\mathrm{V}$ electron kinetic energy with energy resolution 0.25 eV. Measured absolute cross sections near 0 eV range from ${\ensuremath{\sigma}}_{35d}\ensuremath{\approx}7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ to ${\ensuremath{\sigma}}_{50d}\ensuremath{\approx}4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}\text{ }\text{ }{\mathrm{c}\mathrm{m}}^{2}$. The energy dependence is consistent with that of widely used binary encounter approximation cross sections, and ${\ensuremath{\sigma}}_{n}$ follows a power law in $n$. The measured cross sections are 14 to 24 times larger than theoretically predicted values. This enhancement may signal the effect of large polarizabilities of high Rydberg states not yet accounted for in ionization theories.

Physical Review LettersSep 12, 200318 citations

Collisional excitation of Na-Rydberg atoms

Kriti Batra, Vinod Prasad, Man Mohan

The European Physical Journal DAug 1, 20022 citations

l=3,4,\mathrm{and} 5

levels in various Rydberg states of sodium are analyzed to yield values for the core polarizabilities. Effective values of the dipole and quadrupole polarizability of 1.0015(15) and 0.48(15) a.u., respectively, are obtained. Implications for the precise determination of the structure of highly excited Rydberg states in alkali atoms are discussed.

We have observed electron impact ionization of highly excited sodium Rydberg atoms in

ns

and

nd

states,

n=35--51

, below

E=2\text{ }\text{ }\mathrm{e}\mathrm{V}

electron kinetic energy with energy resolution 0.25 eV. Measured absolute cross sections near 0 eV range from ${\ensuremath{\sigma}}_{35d}\ensuremath{\approx}7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ to ${\ensuremath{\sigma}}_{50d}\ensuremath{\approx}4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}\text{ }\text{ }{\mathrm{c}\mathrm{m}}^{2}$. The energy dependence is consistent with that of widely used binary encounter approximation cross sections, and ${\ensuremath{\sigma}}_{n}$ follows a power law in

n

. The measured cross sections are 14 to 24 times larger than theoretically predicted values. This enhancement may signal the effect of large polarizabilities of high Rydberg states not yet accounted for in ionization theories.