Measurements of energy and angular distribution of hot electrons and protons emitted from a p- and s-polarized intense femtosecond laser pulse driven thin foil target

Abstract

The energy spectra and angular distributions of hot electrons as well as protons emitted from a 3-μm-thick tantalum foil irradiated by a 70-fs laser pulse with an intensity of ∼1018W∕cm2 are measured. Three hot electron flows are found, in the rear target normal, specular, and target surface directions. The angular distribution of hot electrons is found to depend on the polarization of the incident light. The measured energy spectrum of hot electrons in the rear target normal direction can explain the generated proton beam.