Showing papers by "Stefano Atzeni published in 2003"
TL;DR: In this article, the authors present theoretical and numerical investigations of several fundamental issues of relevance to fast ignition from the stage of electron generation and transport to that of proton energy deposition, including electron beam instabilities, electron transport in solid-density plasma, proton transport in the coronal plasma, and requirements for proton beam driven ignition.
Abstract: In recent years, several schemes for laser-driven fast ignition (FI) of inertial confinement fusion targets have been proposed. In all schemes, a key element is the conversion of the energy of a Petawatt laser pulse into a beam of strongly relativistic electrons and the transport of the latter into a dense plasma or a solid target. The electron beam may either drive ignition directly or be used to accelerate a proton beam which is in turn used to ignite. Both ignition scenarios involve a number of physical processes which are widely unexplored and challenging for theory and simulation. In this contribution, we present theoretical and numerical investigations of several fundamental issues of relevance to FI from the stage of electron generation and transport to that of proton energy deposition, including electron beam instabilities, electron transport in solid-density plasma, proton transport in the coronal plasma, and requirements for proton beam driven ignition.
47 citations
TL;DR: The deceleration-phase ablative Rayleigh-Taylor instability of igniting and nonigniting inertial fusion capsules is studied by high-resolution two-dimensional Lagrangian fluid simulations and it is found that growth reduction of the dp-RTI with respect to classical RTI results from the advection of perturbed fluid elements outside a thin unstable fluid layer.
Abstract: The deceleration-phase (dp) ablative Rayleigh-Taylor instability (RTI) of igniting and nonigniting inertial fusion capsules is studied by high-resolution two-dimensional Lagrangian fluid simulations It is found that growth reduction of the dp-RTI with respect to classical RTI results from the advection of perturbed fluid elements outside a thin unstable fluid layer Within this layer, at fixed Lagrangian position, perturbations grow approximately classically
20 citations
18 Dec 2003
TL;DR: In this article, theoretical and numerical investigations are presented concerning several fundamental issues of relevance to Fast Ignition, including electron beam instabilities, electron transport in solid-density materials, and requirements for protonbeam driven ignition.
Abstract: In all recently proposed schemes for laser-driven Fast Ignition (Fl) of Inertial Confinement Fusion (ICF) targets,two key elements are the conversion of the energy of a Petawatt laser pulse into a beam of strongly relativisticelectrons and its transport through a dense plasma or a solid target. The electron beam may either drive ignitiondirectly or be exploited to accelerate a proton beam which in turn is used to ignite the target. Both approaches to FT involve a number of physical processes that are challenging for theory and simulation. In this paper, theoretical and numerical investigations are presented concerning several fundamental issues of relevance to Fl,including electron beam instabilities, electron transport in solid-density materials, and requirements for protonbeam driven ignition.Keywords: Fast Ignition, energy conversion, electron and ion beam transport, proton beam driven ignition. 1. INTRODUCTION An essential element of Fast Ignition (Fl) of ICF targets is the conversion of the energy of a Petawatt laser pulseinto a beam of strongly relativistic electrons. In the original proposal,' the electron beam is generated by directinteraction of the laser pulse with the coronal plasma and reaches the precompressed fuel core after propagatingin the dense plasma region. The electron beam is expected to carry a current of several MegaAmperes, and itstransport properties are thus affected by the self-generated electric and magnetic fields, by beam instabilities andby inefficient charge neutralization due to low conductivity of the background electrons. Efficient energy transportis also a key factor in alternative FT schemes.2 Electric field generation by relativistic electrons penetrating in
1 citations