Fast Electron Heating of Shock Compressed Plasmas

The upgraded Vulcan laser is particularly well suited to the studies of the fast ignitor route to inertially confined fusion (ICF). This scheme uses an ultra-short pulse to ignite a pre-compressed fuel pellet. Electrons, generated in the interaction between the high intensity laser pulse and the compressed fuel, travel through the target to the high density region where they deposit their kinetic energy, heating the fuel and triggering ignition.

The experiment, conducted by a team led by Dr Dimitri Batani (Univ. of Milan) and funded through the Framework IV Large-Scale Facilities Access Scheme, compared the electron energy deposition rate in a plasma compressed to a few times solid density with that in cold material. It was shown that under these conditions ionised, compressed plastic is less effective, by a factor of two, at stopping the fast electrons than uncompressed, unionised plastic. Further work is planned, at yet higher density, to enable extrapolations to the fast ignitor regime.

Andre Bernadinello of Milan University and Fransesca Pisani of Ecole Polytechnique, France align the target in the EU Large Scale Facility access experiment to study fast electron heating of shock compressed plasmas (97RC1761).		Streak camera images of shock breakouts from targets of different thicknesses.