Mean excitation energies of Al 2O 3 and SiO 2 extracted from alpha particle stopping power measurements

Abstract

Previously reported measurements of the stopping powers of Al 2O 3 and SiO 2 for 0.2–2 MeV and 5.48 MeV alpha particles have been analyzed for extraction of values of parameters from modified Bethe-Bloch theory. Two-parameter fits were conducted for values of mean excitation energy and one of two available Barkas-effect parameters. Resulting mean excitation energies lay below additivity-based predictions, whereas Barkas-effect parameters essentially coincided with values prescribed by the formalism.