Phase shifts and resonances for electron scattering by He below the N = 2 threshold

Journal Article · Sat Feb 01 04:00:00 EST 1986 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.33.824· OSTI ID:6286222

Oza, D H

The scattering of electrons by He ions has been studied below the N = 2 threshold of the ion. A pseudostate close-coupling method has been used to examine the scattering in the nonresonant and resonant regions. The calculations are performed using an algebraic variational method. Extensive pseudostate basis sets of differing characters are employed. In the nonresonant region, short-range electron-electron correlations are emphasized. In the vicinity of the resonances, the dominant projectile-target electron correlations are comparatively long range. S-, P-, and D-wave phase shifts of high accuracy are obtained for both the singlet and the triplet spin states. The present phase shifts agree very well with those obtained by Shimamura by a variational procedure for the S wave and with those of McGreevy and Stewart by a many-body perturbation method for the singlet P wave. The present phase shifts are in disagreement with the polarized orbital results of Khan et al. Resonance parameters are calculated for 15 S-wave resonances, 16 P-wave resonances, and 19 D-wave resonances with the outer electron extending up to napprox. =8. Estimates of quantum defects and the reduced widths are obtained for various Rydberg series of the doubly excited states. A number of the high-lying resonances are predicted for the first time. The agreement of the present energy values and the auotionization widths with the available experimental values is excellent.

• Research Organization: Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001
• OSTI ID: 6286222
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 33:2; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR MOMENTUM
AUTOIONIZATION
CHARGED PARTICLES
COLLISIONS
ELASTIC SCATTERING
ELECTRON COLLISIONS
ELECTRON-ELECTRON INTERACTIONS
ELECTRON-ION COLLISIONS
HELIUM IONS
INELASTIC SCATTERING
INTERACTIONS
ION COLLISIONS
IONIZATION
IONS
LEPTON-LEPTON INTERACTIONS
PARTICLE INTERACTIONS
PHASE SHIFT
RESONANCE SCATTERING
SCATTERING
SYMMETRY