Multi-MeV Proton Source Investigations in Ultraintense Laser-Foil Interactions

Abstract
A study of the properties of multi-MeV proton emission from thin foils following ultraintense laser irradiation has been carried out. It has been shown that the protons are emitted, in a quasilaminar fashion, from a region of transverse size of the order of 100200   μm. The imaging properties of the proton source are equivalent to those of a much smaller source located several hundred μm in front of the foil. This finding has been obtained by analyzing proton radiographs of periodically structured test objects, and is corroborated by observations of proton emission from laser-heated thick targets.