Summary form only given. We have conducted several experiments in order to begin to understand the how energy is converted from high intensity laser light into directed energy flow of electrons and ions in dense material. Our results to date indicate a complex interaction, in which the laser light, from petawatt class lasers, is converted into hot electrons (/spl sim/10 MeV) which stream forward, each carrying an Alfven current. These electrons exit the back of the target (usually on the order of 10's of microns in depth) and create a sheath electric field that acts as an efficient accelerator of protons from the back surface. This acceleration has given rise to very high-energy protons (<60 MeV) that appear to have a reasonably tight phase space distribution.
展开▼
