Date: August 1978
Creator: Monigold, G.; McDaniel, Floyd Del. (Floyd Delbert), 1942-; Duggan, Jerome L.; Rice, R.; Toten, A.; Mehta, R. et al
Description: This article discusses K-shell ionization of elements ₁₅P to ₂₈Ni for 0.4 to 3.8 MeV/amu ₅¹⁰B-ion bombardment. Abstract: K-shell x-ray production cross sections, Kβ/Kα x-ray intensity ratios and Kα and Kβ x-ray energy shifts have been determined for thin solid targets of ₁₅P, ₁₉K, ₂₀Ca, ₂₁Sc, ₂₂Ti, ₂₃V, ₂₅Mn, ₂₆Fe, ₂₇Co, and ₂₈Ni for 4-38-MeV ₅¹⁰B ion bombardment. Comparisons of the cross sections were made to direct Coulomb ionization and electron-capture theories by means of fluorescence yields corrected for multiple-ionization effects. The dominant contribution to K-vacancy production for these projectile-target combinations is believed to be direct ionization. Electron capture is expected to be important only for the lighter target elements and then primarily at the higher velocities. The direct-ionization theories employed were the binary-encounter approximation and the plane-wave Born approximation (PWBA) both of which overestimated the experimental data especially at the lower incident ion velocities. The PWBA was modified for increased target-electron binding, Coulomb deflection of the incident ion, polarization of the target-electron wave functions due to the passage of the incident ion, and relativistic target-electron velocities. The experimental data were found to agree quite well with the sum of the theoretical predictions of the modified PWBA and electron capture.
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