Electron and positron scattering from atoms

Thesis/Dissertation · Wed Dec 31 23:00:00 EST 1986

OSTI ID:5963566

Nahar, S N

Four distinct projects carried out are discussed. First, differential and integrated cross sections for the elastic scattering of low- and intermediate-energy (3-300 eV) positrons and electrons by argon atoms are calculated. Higher transport cross sections, representing moments of 1 - (cos theta)/sup n/, for these systems are also obtained for n = 1-4. Model potentials are used to represent the interactions between positrons or electrons and argon atoms. For each impact energy, the phase shifts of the lower partial waves are obtained exactly by numerical integration of the radial equation. Second, closed form expressions for the contributions of higher partial waves (2 ell > n-3) to the elastic scattering amplitude for various long range interactions, which fall off as r/sup -n/ as r ..-->.. infinity, are obtained for n ranging from 3 to 8. Third, the differential and total cross sections for the formation of positronium in its ground state from Li and Na atoms by the impact of intermediate-energy positrons are calculated in the first Born and the distorted wave Born approximations. Finally, formation of positronium (Ps) in different states by the impact of intermediate energy (20-500 eV) positrons on atomic hydrogen are calculated using the first Born approximation (FBA) and the distorted-wave Born approximation.

• Research Organization: Wayne State Univ., Detroit, MI (USA)
• OSTI ID: 5963566
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
ARGON
ATOM COLLISIONS
COLLISIONS
CROSS SECTIONS
ELASTIC SCATTERING
ELECTRON COLLISIONS
ELECTRON-ATOM COLLISIONS
ELEMENTS
ENERGY RANGE
EV RANGE
FLUIDS
GASES
HYDROGEN
LITHIUM
METALS
NONMETALS
POSITRON COLLISIONS
POSITRON-ATOM COLLISIONS
POSITRONIUM
PRODUCTION
RARE GASES
SCATTERING
SODIUM