Enhanced energy coupling by using structured nano-wire targets

We have investigated the interaction of ultra intense laser light with a carbon nanotube (CNT) target. The experimental results show an increased electron acceleration and a very low laser reflection as compared to non-structured targets. In addition, interferograms show very weak plasma expansion in front of the CNT target whereas the flat target creates a considerable amount of preformed plasma. A 2-D PIC calculation indicates that high laser absorption is possible via a Brunel mechanism following the ponderomotive heating in the expanded plasma between nanotubes