%0 Journal Article %T Proton acceleration mechanisms in high-intensity laser interaction with thin foils %+ Département de Physique Théorique et Appliquée (DPTA) %+ Laboratoire d'optique appliquée (LOA) %A d'Humières, Emmanuel %A Lefebvre, Erik %A Gremillet, Laurent %A Malka, Victor %< avec comité de lecture %@ 1070-664X %J Physics of Plasmas %I American Institute of Physics %V 12 %N 6 %P 062704 %8 2005-06-02 %D 2005 %R 10.1063/1.1927097 %K plasma accelerators %K plasma light propagation %K plasma simulation %K plasma shock waves %K plasma heating by laser %Z PACS 52.38.Kd; 52.38.Dx; 52.50.Jm; 52.35.Tc; 52.65.Rr %Z Physics [physics]/Physics [physics]/Optics [physics.optics]Journal articles %X The interaction of short and intense laser pulses with plasmas or solids is a very efficient source of high-energy ions. This paper reports the detailed study, with particle-in-cell simulations, of the interaction of such a laser pulse with thin, dense targets, and the resulting proton acceleration. Depending on the laser intensity and pulse duration, the most energetic protons are found to come from the front, the core, or the back of the target. The main accelerating mechanisms discussed in this paper are plasma expansion acceleration, where proton acceleration is driven by the hot electron population, and shock acceleration, originating from the laser ponderomotive potential imposed at the front target surface. Three main regimes of proton acceleration are defined and the parameters for which each regime is dominant are obtained. For irradiances close to 10^20 W/cm^2, the highest proton energies are obtained from thin foils efficiently heated by relativistic transparency. At larger intensities, a complex interplay between collisionless shock acceleration and plasma expansion acceleration is evidenced. %G English %L hal-00569987 %U https://hal-polytechnique.archives-ouvertes.fr/hal-00569987 %~ CEA %~ X %~ ENSTA %~ CNRS %~ X-LOA %~ X-DEP %~ X-DEP-PHYS %~ PARISTECH %~ ENSTA_LOA %~ DAM