Double ionization of He(1[ital s][sup 2]) and He(1[ital s]2[ital s] [sup 3][ital S]) by a single high-energy photon
- Physics Department, University of Southern California, Los Angeles, California 90089-0484 (United States)
We have calculated the energy and angular distributions for double ionization of He(1[ital s][sup 2]) and He(1[ital s]2[ital s] [sup 3][ital S]) by one photon, over a range of photon energies up to a few keV. The calculations were based on using a fairly accurate initial-state wave function, determined so as to exactly satisfy the Kato cusp conditions, and a final-state wave function which is a product of three Coulomb wave functions modified by a short-range correction term. There are at least three different mechanisms for double ionization, and each one leaves a mark on the angular distribution. When the energies of the two electrons are equal, the contribution of each mechanism to the angular asymmetry parameter can be estimated on theoretical grounds; we compare these estimates with the calculated results to give a further indication of the roles of the various mechanisms. Concerning the shapes of the energy and angular distributions, we find significant differences between double ionization of singlet and triplet helium; in particular, the probability for one high-energy photon to eject two equal-energy electrons from triplet helium nearly vanishes owing to the Pauli exclusion principle and to interference effects resulting from antisymmetrization. In two appendixes we present some details of the integration involved in the calculations.
- OSTI ID:
- 5008499
- Journal Information:
- Physical Review A; (United States), Vol. 49:5; ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HELIUM
PHOTOIONIZATION
ANGULAR DISTRIBUTION
ENERGY
INTERFERENCE
KEV RANGE
WAVE FUNCTIONS
DISTRIBUTION
ELEMENTS
ENERGY RANGE
FLUIDS
FUNCTIONS
GASES
IONIZATION
NONMETALS
RARE GASES
664200* - Spectra of Atoms & Molecules & their Interactions with Photons- (1992-)