Positron scattering from rare gases (He, Ne, Ar, Kr, Xe, and Rn): Total cross sections at intermediate and high energies

Journal Article · Sat Aug 01 00:00:00 EDT 1992 · Physical Review A. General Physics; (United States)

DOI:https://doi.org/10.1103/PhysRevA.46.1279· OSTI ID:7286094

Baluja, K L; Jain, A ^[1]

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1. Physics Department, Florida A M University, Tallahassee, Florida 32307 (United States) Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida 32304 (United States)

The total (elastic plus inelastic) cross sections for positron scattering from all the rare gases are reported at intermediate and high energies (20--1000 eV), where experimental data are available for comparison except for the case of radon gas. A complex-optical-potential ({ital V}{sub opt}({ital r})) approach is employed in which the real part (static plus polarization terms) is calculated from Hartree-Fock or Dirac-Hartree-Fock target wave functions. The imaginary part of the optical potential, i.e., the absorption potential ({ital V}{sub abs}{sup +}({ital r})), is derived for each gas semiempirically from the corresponding electron absorption potential ({ital V}{sub abs}{sup {minus}}({ital r})) in the form of {ital V}{sub abs}{sup +}({ital r})={ital f}({ital k},{ital r}){ital V}{sub abs}{sup {minus}}({ital r}), where {ital f}({ital k},{ital r}) depends on the incident energy ({ital k}{sup 2}) and radial distance ({ital r}). The {ital V}{sub abs}{sup {minus}} is taken from the work of Truhlar and co-workers. The {ital V}{sub opt}({ital r}) is treated exactly in a partial-wave analysis under the variable-phase method. With the present form of {ital V}{sub opt}({ital r}), we are able to reproduce experimental {sigma}{sub {ital t}} values at all energies considered here. An additional feature of the present results is that the inelastic cross sections compare very well with the measured inelastic (sum of positronium formation, excitation, and ionization cross sections) values for rare gases, where such experimental data are available. The {sigma}{sub {ital t}} for the positron-Rn system are predicted.

• OSTI ID: 7286094
• Journal Information: Physical Review A. General Physics; (United States), Vol. 46:3; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
RADON
POSITRON-ATOM COLLISIONS
RARE GASES
CALCULATION METHODS
COMPARATIVE EVALUATIONS
EV RANGE 10-100
EV RANGE 100-1000
EXPERIMENTAL DATA
SCATTERING
TOTAL CROSS SECTIONS
ATOM COLLISIONS
COLLISIONS
CROSS SECTIONS
DATA
ELEMENTS
ENERGY RANGE
EV RANGE
EVALUATION
FLUIDS
GASES
INFORMATION
NONMETALS
NUMERICAL DATA
POSITRON COLLISIONS
664500* - Special Atoms & Molecules- (1992-)