Fast Proton Generation from Ultrashort Laser Pulse Interaction with Double-Layer Foil Targets

Abstract

The results of studies of fast-proton generation from foil targets irradiated by 1-ps laser pulse at ${10}^{17}\phantom{\rule{0ex}{0ex}}\mathrm{W}/\mathrm{cm}{}^{2}$ are presented. It is shown that a considerable increase in proton energy and current is possible when a double-layer foil target containing a high- $Z$ layer and a low- $Z$ hydrogen-rich layer is used instead of a single-layer target. Proton energies and current increase with the $Z$ of the high- $Z$ layer and depend essentially on the target and the layer thicknesses. Above ${10}^{9}$ forward-emitted protons of energy $>100\phantom{\rule{0ex}{0ex}}\mathrm{keV}$ have been recorded within a cone angle $<3\ifmmode^\circ\else\textdegree\fi{}$.