Electron-impact ionization of Se2

• Published in: Journal of physics. B, Atomic, molecular, and optical physics Vol. 47; no. 13
• Main Authors: Alna'washi, G A, Aryal, N B, Baral, K K, Thomas, C M, Phaneuf, R A
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 14.07.2014; Institute of Physics
• Subjects: Atomic and molecular collision processes and interactions; Atomic and molecular physics; dynamic-crossed-beams technique; Electron scattering; electron-impact ionization; Electron-ion scattering; excitation and ionization; Exact sciences and technology; excitation-autoionization; LOTZ; Physics; REDA; selenium; Crossed beams; Electron impact ionization; Multiple ionization; Multicharged ions; Electron-ion collisions; Empirical method; Theoretical study; Autoionization; Selenium ions; Excitation; Semiempirical method; Cross sections
• ISSN: 0953-4075; 1361-6455
• DOI: 10.1088/0953-4075/47/13/135203

Absolute cross sections for electron-impact single and multiple ionization of Se2+ ions were measured using the dynamic-crossed-beams technique over the energy range from the ionization threshold to 500 eV and compared to direct ionization cross sections predicted by the Lotz semi-empirical formula. The single-ionization cross section appears to be dominated by excitation-autoionization of the 4s and 3d inner subshells. The double-ionization measurements are reasonably well accounted for by the semi-empirical fitting formula of Shevelko et al that includes both direct double ionization of the outer 4p subshell and single ionization of the 3p and 3d subshells followed by autoionization. In addition to direct triple ionization, 3p and 3s ionization followed by double autoionization and excitation of the 3p and 3s subshells followed by triple autoionization likely contribute to the triple ionization cross section.