K -shell ionization cross sections of Al, Si, S, Ca, and Zn for oxygen ions in the energy range 1. 1--8 MeV

Journal Article · Sun Mar 01 04:00:00 EST 1992 · Physical Review A. General Physics; (United States)

DOI:https://doi.org/10.1103/PhysRevA.45.2842· OSTI ID:7276780

Geretschlaeger, M ^[1]; Smit, Z ^[2]; Steinbauer, E ^[1]

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1. Institut fuer Experimentalphysik, Johannes-Kepler-Universitaet Linz, A-4040 Linz (Austria)
2. J. Stefan Institute, E. Kardelj-University, Ljubljana (Slovenia)

{ital K}-shell ionization cross sections induced by 1.1--8-MeV oxygen ions in Al, Si, S, Ca, and Zn were measured using different target thicknesses. The cross sections for vanishingly thin and for charge-equilibrium targets were obtained by extrapolation. The experimental results are compared to the perturbed stationary-state approximation with energy-loss, Coulomb, and relativistic corrections (ECPSSR) cross sections (Brandt and Lapicki, Phys. Rev. A 23, 1717 (1981)), to the modification of the ECPSSR theory (MECPSSR) (Benka, Geretschlaeger, and Paul, J. Phys. (Paris) Colloq. Suppl. 12, C9-251 (1987)), to the theory for direct Coulomb ionization of the 1{ital s}{sigma} molecular orbital (Montenegro and Sigaud, J. Phys. B 18, 299 (1985)), and to several semiclassical approximation codes using either the united atom binding procedure or the variational approach of Andersen {ital et} {ital al}. (Nucl. Instrum. Methods 192, 79 (1982)). The cross sections were also compared to the statistical molecular-orbital theory of inner-shell ionization for (nearly) symmetric atomic collisions (Mittelman and Wilets, Phys. Rev. 154, 12 (1967)). For fast collisions ({xi}{similar to}1), the ionization cross sections are well reproduced by theories for direct Coulomb ionization. For slower collisions ({xi}{lt}1), the experimental cross sections are systematically higher than the direct-ionization values, but they agree satisfactorily with the summed cross sections for direct Coulomb ionization and for molecular-orbital ionization. Best agreement (within a factor of 2) was found for the sums of MECPSSR and statistical cross sections.

• OSTI ID: 7276780
• Journal Information: Physical Review A. General Physics; (United States), Journal Name: Physical Review A. General Physics; (United States) Vol. 45:5; ISSN 1050-2947; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

664300* -- Atomic & Molecular Physics-- Collision Phenomena-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ALKALINE EARTH METALS
ALUMINIUM
ATOM COLLISIONS
BACKSCATTERING
CALCIUM
CHARGED PARTICLES
CHEMICAL ANALYSIS
COLLISIONS
CROSS SECTIONS
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY RANGE
FILMS
INNER-SHELL IONIZATION
ION COLLISIONS
ION-ATOM COLLISIONS
IONIZATION
IONS
K SHELL
METALS
MEV RANGE
MEV RANGE 01-10
NONDESTRUCTIVE ANALYSIS
NONMETALS
OXYGEN IONS
SCATTERING
SEMIMETALS
SILICON
SULFUR
TARGETS
THIN FILMS
X-RAY EMISSION ANALYSIS
ZINC