K-K-electron transfer andK-shell-vacancy production cross sections for Ti bombarded bySi28and

Abstract

Single and double E-E-electron transfer and the K-shell-vacancy production cross sections for Ti bombarded by Si and S beams at energies varying between 1.2S and 4.7 MeV/amu have been determined, in the limit of zero target thickness, from the thickness variation of the Ti X x-ray yield with ion beams having 0, 1, or 2 vacancies in their K shell. From the measured energy shift and the intensity ratios of Ect, KP lines, the average number of 2p and 3p vacancies were determined from which the average value of the fluorescence yield co+ was deduced using the statistical scaling procedure of Larkins [J. Phys. B 4, L29 (1971)]. The single-electron transfer cross sections are compared with the calculations of Brinkman and Kramer as formulated by Nikolaev [Sov. Phys. JETP 24, 847 (1967)] and those of McDaniel [Phys. Rev. A 22, 1896 (1980)] and the modified two-center atomic-orbital-expansion model (AO+) of Fritsch and Lin [J. Phys. B 15, 1255Phys. B 15, (1982]. The double-electron transfer cross sections are also compared with the AO+ predictions. The K-shell-vacancy production data are compared with calculations based on the perturbed-stationary-state approach with the Coulomb-deflection, bindingenergy, and relativistic corrections (ECPSSR) included. In addition, the projectile cross sections for single-electron capture and loss have also been deduced at a few energies.PACS number(s): 34.50.Fa, 34.70.+e

Single and doubleK-shell ionization and electron-transfer cross sections for Fe and Ni bombarded by S ions and Fe by Si ions at 1.25–4.70 MeV/amu

“…hypersatellite intensity was used to study the double K-vacancy production cross sections [1,7]. The measured intensities were corrected for the absorber thickness, and the normalized yields were used for further data analysis.…”

“…(1) (for details see Refs. [7,11,17]). These fits provided the cross sections for target E x-ray production, 0'&x, in the limit of zero target thickness and are used for further analysis.…”

“…As in our earlier work [7], the value of u~was derived from the measured values of the energy shifts of the Ea and KP components and their intensity ratios. Correlating these shifts and ratios with the average number of 2p and 3p vacancies and using the statistical scaling procedure of Larkins [18] the ale values were obtained at all the energies of Si and S ions.…”

“…The experimental details and the measurement techniques are described in our earlier papers [7,11] and hence only a brief outline will be provided. Si and S beams of energy varying between 1.5 and 4.7 MeV/amu were obtained &om the BARC-TIFR Pelletron accelerator at Bombay.…”

“…These calculations have been extended by Fritsch and Lin [6] to include more numbers of atomic orbitals (AO's) of both target and projectile (instead of two states as in TSAE) in the atomic-wavefunction expansion model. The single and double K-K electron-transfer cross sections, measured recently [7) for Si and S ions bombarding the Ti target, were found to be in good agreement with these AO calculations [6]. In order to test the prediction of AO calculations for asymmetric collision systems we have measured the single and double K-K transfer cross sections for the collision system Si or S~Fe and S~Ni (Zi/Z2 --0.54 -0.62, where subscripts 1 and 2 refer to projectile and target, respectively).…”