Large-angle scattering in positron-helium and positron-krypton collisions

Journal Article · Wed Nov 01 04:00:00 EST 1989 · Physical Review (Section) A: General Physics; (USA)

DOI:https://doi.org/10.1103/PhysRevA.40.4947· OSTI ID:5249884

Schultz, D R; Reinhold, C O; Olson, R E ^[1]

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1. Department of Physics and Laboratory for Atomic and Molecular Research, University of Missouri-Rolla, Rolla, Missouri 65401 (US)

We have calculated differential cross sections as a function of the projectile scattering angle for positron-helium and positron-krypton collisions using the classical-trajectory Monte Carlo technique. These intermediate-velocity collisions have been simulated by various independent-electron and {ital n}-electron models, using both screened Coulomb and quantum model potentials to approximate the effects of electron-electron interactions. These several models all indicate that scattering of positrons to large angles in ionizing collisions persists to high impact velocities. In a previous work (Phys. Rev. A 38, 1866 (1988)) we proposed that the recent experiments that have measured the total cross section for positronium formation could be affected by the loss of positron flux due to incomplete confinement after large-angle scattering. Here, utilizing these newly calculated differential-scattering cross sections, adjustments are computed that account for the difference between the experimental and theoretical behaviors of the positronium formation cross section. Further, it is demonstrated that large-angle scattering in the elastic channel is important for one of the experiments. We have also computed total cross sections for ionization and charge transfer for collisions of protons with krypton. Good agreement is obtained in these cases with experimental measurements.

• OSTI ID: 5249884
• Journal Information: Physical Review (Section) A: General Physics; (USA), Journal Name: Physical Review (Section) A: General Physics; (USA) Vol. 40:9; ISSN PLRAA; ISSN 0556-2791
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR DISTRIBUTION
ATOM COLLISIONS
COLLISIONS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
DISTRIBUTION
ELASTIC SCATTERING
ELEMENTS
FLUIDS
GASES
HELIUM
INELASTIC SCATTERING
KRYPTON
MONTE CARLO METHOD
NONMETALS
POSITRON COLLISIONS
POSITRON-ATOM COLLISIONS
RARE GASES
SCATTERING