Powell, Cedric J.Llovet Ximenes, XavierSalvat Gavaldà, Francesc2019-02-052019-02-052016-05-130021-8979https://hdl.handle.net/2445/127902We analyzed calculated cross sections for K-, L-, and M-shell ionization by electron impact to determine the energy ranges over which these cross sections are consistent with the Bethe equation for inner-shell ionization. Our analysis was performed with K-shell ionization cross sections for 26 elements, with L-shell ionization cross sections for seven elements, L-3-subshell ionization cross sections for Xe, and M-shell ionization cross sections for three elements. The validity (or otherwise) of the Bethe equation could be checked with Fano plots based on a linearized form of the Bethe equation. Our Fano plots, which display theoretical cross sections and available measured cross sections, reveal two linear regions as predicted by de Heer and Inokuti [in Electron Impact Ionization, edited by T. D. Mark and G. H. Dunn, (Springer-Verlag, Vienna, 1985), Chap. 7, pp. 232-276]. For each region, we made linear fits and determined values of the two element-specific Bethe parameters. We found systematic variations of these parameters with atomic number for both the low-and the high-energy linear regions of the Fano plots. We also determined the energy ranges over which the Bethe equation can be used.18 p.application/pdfeng(c) American Institute of Physics, 2016IonitzacióRaigs XPel·lícules finesFísica nuclearIonizationX-raysThin filmsNuclear physicsinfo:eu-repo/semantics/article6706792019-02-05info:eu-repo/semantics/openAccess27546903