Understanding the role of fast electrons in the heating of dense matter: experimental techniques and recent results

An intense laser impinging upon dense matter converts a large fraction of its energy into fast electrons. (Here we take "fast" to mean electrons that are much more energetic than the normal Boltzmann-like distribution measured in the tens to hundreds of eV.) Upon transiting the interior of the dense matter, these electrons are responsible for isochoric heating of the material. Just how these electrons traverse the material, and various interfaces within the material, is a subject of substantial amounts of computation and theory, and recently, experiments. Here we outline the nature of the heating mechanisms, and the current level of understanding of the complex physical processes. In particular we discuss new experimental techniques to record essential features of this transport problem. (C) 2003 Elsevier Science Ltd. All rights reserved.