Direct ionization and electron capture in M-shell x-ray production by fluorine ions
Measurements of M-shell x-ray production cross sections are reported for thin solid targets of /sub 79/Au, /sub 82/Pb, /sub 83/Bi, and /sub 92/U. Fluorine ions of energies 25, 27, and 35 MeV and charge states of 4, 5, 6, 8, and 9 were used. The microscopic cross sections were determined from measurements made with targets ranging in thickness from approx.1 to approx.300 ..mu..g/cm/sup 2/. An enhancement in the target M-shell x-ray production cross section was observed for fluorine ions with one or two K-shell vacancies over those without a K-shell vacancy. The sums of cross sections for direct ionization to the target continuum and electron capture to the projectile's L,M,N, . . . shells are inferred from charge state q = 4,5,6 data. The first Born calculations overpredict the cross-section data at all energies. Cross sections for electron capture from the target M shell to the projectile K shell for one (q = 8) and two (q = 9) K-shell vacancies in the projectile are also overpredicted by the first Born approximation for electron capture, i.e., the Oppenheimer-Brinkman-Kramers approximation of Nikolaev. The data are in good agreement with the ECPSSR theory of Brandt and Lapicki, which accounts for the energy-loss, Coulomb-deflection, and relativistic effects in the perturbed-stationary-state theory.
- Research Organization:
- Department of Physics, North Texas State University, Denton, Texas 76203
- OSTI ID:
- 5267847
- Journal Information:
- Phys. Rev. A; (United States), Vol. 28:5
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BISMUTH
ION-ATOM COLLISIONS
FLUORINE IONS
GOLD
LEAD
URANIUM
AUGMENTATION
BORN APPROXIMATION
CROSS SECTIONS
K SHELL
M SHELL
MEV RANGE 10-100
MULTICHARGED IONS
PSS METHOD
THIN FILMS
X RADIATION
ACTINIDES
ATOM COLLISIONS
CHARGED PARTICLES
COLLISIONS
ELECTROMAGNETIC RADIATION
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY RANGE
FILMS
ION COLLISIONS
IONIZING RADIATIONS
IONS
METALS
MEV RANGE
RADIATIONS
TRANSITION ELEMENTS
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena