Spectrum of potential-energy curves for the ${He}_{2}^{+}$ system

Publisher Website

1 December 1976

journal article
research article
Published by American Physical Society (APS) in Physical Review A

Vol. 14 (6) , 2055-2060
https://doi.org/10.1103/physreva.14.2055

Abstract

Low-energy, collisional excitation of neutral helium in He-

{He}^{+}

collisions is investigated using the potential-energy curves for the molecular ions. Ground and excited states of the

{}^{2}Σ_{g}^{+}

,

{}^{2}Σ_{u}^{+}

,

{}^{2}Π_{g}

, and

{}^{2}Π_{u}

states are calculated using an ab initio configuration-interaction method for the

n = 2

neutral excitations of helium. A threshold of 23.5 eV is determined for the

{}^{1}S

-

2 {}^{3}S

excitation. Thresholds for the

{}^{1}S

-

2 {}^{1}S

-

2 {}^{3}P

and

2 {}^{1}P

states are also estimated from the potential-energy curves.

Σ

-

Π

interactions are also considered to explain the photon polarization reported in the

2 {}^{1}P

excitation cross section. The

{}^{2}Σ_{g}^{+}

spectrum of potential-energy curves appears to dominate the

Σ

-

Σ

radial interactions, while the

{}^{2}Σ_{u}^{+}

and

{}^{2}Π_{u}

states are apparently necessary to explain the

2 {}^{1}P

cross section.

Keywords

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