Projectile atomic number dependence of the relativistic effect on the K-shell ionization of high Z elements under heavy-ion impact
- Tata Institute of Fundamental Research, Colaba, Mumbai-400 005 (India)
Absolute K-shell ionization cross sections of Sb, Au, and Bi have been measured in collisions with highly charged C, O, and S ions having energies between 2 and 6.25 MeV/u. The data are presented along with the earlier results with F and Si ions as projectiles. The measured data have been compared with theoretical models based on the semiclassical approximation including relativistic effect and perturbed stationary state approximation including the corrections for energy loss, Coulomb deflection, and relativistic effects. The data were analyzed in term of relativistic effect on K-ionization: its dependence on the projectile atomic number, target atomic number and projectile energy. The present data set along with our recently measured similar data for F and Si ions show that the relativistic effect increases with projectile atomic number and decreases with projectile velocity. A comparison of the experimental data and relativistic calculations, both normalized to nonrelativistic model, show the inadequacy of the theoretical models in describing the relativistic correction on K-shell ionization. For example, the theoretical predictions agree with experimental findings for O ions on Bi while the same theoretical predictions deviate from the experimental results by about a factor of 2 for Si and S on Bi, the theory being higher.
- OSTI ID:
- 20974749
- Journal Information:
- Physical Review. A, Vol. 74, Issue 5; Other Information: DOI: 10.1103/PhysRevA.74.052714; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
Similar Records
L-subshell ionization of Au, Tl, Pb, Bi, Th, and U by protons
Projectile dependence of single-K multiple-L shell vacancy production in argon: A universal scaling of