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 00:00:00 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), Vol. 45:5; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

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