Relativistic approach for e sup + scattering from argon

Journal Article · Fri Feb 01 04:00:00 EST 1991 · Physical Review, A; (USA)

DOI:https://doi.org/10.1103/PhysRevA.43.1275· OSTI ID:5622250

Nahar, S N ^[1]; Wadehra, J M ^[2]

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1. Department of Astronomy, Ohio State University, Columbus, Ohio 43210 (US)
2. Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48202 (USA)

Differential and integrated elastic, integrated total cross sections as well as various polarization parameters--the spin polarization {ital P} and the parameters {ital T} and {ital U} describing the change in the polarization vector during scattering--for the scattering of electrons and positrons from argon in the energy range of 3--300 eV are calculated using the relativistic Dirac equation. The real part of the projectile-target interaction is represented by a sum of model potentials. The phase shifts for large angular momenta {h bar}{ital l} are calculated using the Born approximation. The relativistic calculations for the differential and integrated elastic cross sections obtained using the pure real potential show almost no improvement over those obtained nonrelativistically for positron scattering from argon while similar calculations show some effects, except at low energies ({le}5 eV) where relativistic terms are sensitive to the form of potentials used, on the values of the differential cross sections for electron scattering from argon. The polarization parameter {ital P} for electron scattering is found to be in good agreement with various calculated and measured values. A few different models of the absorption potential for the inelastic processes are used to calculate the integrated inelastic and the integrated total cross sections for positron and electron scattering from argon. It is noticed that even though the integrated elastic and the integrated total cross sections for the scattering of positrons and electrons calculated using some complex model potential agree well with the corresponding measured values, the differential cross section curves using the same model potentials can differ considerably from each other as well as from the experimental values.

• OSTI ID: 5622250
• Journal Information: Physical Review, A; (USA), Journal Name: Physical Review, A; (USA) Vol. 43:3; ISSN 1050-2947; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ATOM COLLISIONS
COLLISIONS
COUPLING
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
DIFFERENTIAL EQUATIONS
DIRAC EQUATION
ELASTIC SCATTERING
ELECTRON COLLISIONS
ELECTRON-ATOM COLLISIONS
ELEMENTS
ENERGY RANGE
EQUATIONS
EV RANGE
FLUIDS
GASES
INTEGRAL CROSS SECTIONS
INTERMEDIATE COUPLING
L-S COUPLING
NONMETALS
ORIENTATION
PARTIAL DIFFERENTIAL EQUATIONS
PHASE SHIFT
POSITRON COLLISIONS
POSITRON-ATOM COLLISIONS
RARE GASES
SCATTERING
SPIN ORIENTATION
WAVE EQUATIONS