Si K-shell ionization and electron transfer cross sections: Solid targets

Journal Article · Sun Oct 01 04:00:00 EDT 1978 · Phys. Rev., A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.18.1373· OSTI ID:6687188

Tawara, H; Richard, P; Gray, T J; Newcomb, J; Jamison, K A; Schmiedekamp, C; Hall, J M

The Si K x-ray production cross sections for F/sup q/+(q = 3--9) ion impact in the energy range of 0.4--2.2 MeV/amu are determined in the limit of a vanishingly thin target from the observed target thickness dependence of the x-ray yields. The ionization cross sections are deduced from the measured x-ray production cross sections using an average fluorescence yield (omega-tilde = 1.5..omega../sub 0/, where ..omega../sub 0/ is the fluorescence yield for an atom with single K vacancy) determined from high-resolution x-ray spectra and configuration fluorescence yields. For F/sup q/+ (q < or = 6) ion impact, the measured ionization cross sections are compared with the plane-wave-Born-approximation prediction with and without the Coulomb deflection and increased-binding-energy effects. The Si K shell to F K shell electron-transfer cross sections are determined from the difference between the ionization cross sections for F/sup 9 +/ ions and those for F/sup q/+ ions (q < or = 6). The results are compared with the prediction based on the two-state atomic-expansion method and that based on the modified Oppenheimer-Brinkman-Kramers approximation. A comparison is also made between the Si solid-target measurements with those obtained for gaseous Ne and Ar gas targets. The solid-target and gas-target data are consistent at 1.58 MeV/amu. Finally, from a comparison between the measured equilibrium x-ray yields and the calculated x-ray yields using the equilibrium charge distribution of projectiles after passing through foils, it is found that the projectiles have a considerably larger number of K-shell vacancies inside solids than after passing through solids at lower-impact energies.

• Research Organization: Department of Physics, Kansas State University, Manhattan, Kansas 66506
• OSTI ID: 6687188
• Journal Information: Phys. Rev., A; (United States), Journal Name: Phys. Rev., A; (United States) Vol. 18:4; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular &amp; Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
CHARGED PARTICLES
COLLISIONS
CROSS SECTIONS
ELECTRON TRANSFER
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY RANGE
FLUORINE IONS
ION COLLISIONS
IONIZATION
IONS
K SHELL
KEV RANGE
KEV RANGE 10-100
MEV RANGE
MEV RANGE 01-10
SEMIMETALS
SILICON
SPECTRA
X-RAY SPECTRA