Abstract
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.
Highlights
After the recent successful fast ignition (FI) integrated experiment at ILE, Osaka University [1], ultra high-intensity laser systems with considerable energy have been built for demonstration of FI such as GEKKO-LFEX and Omega-EP
The number of fast electrons changes from shot to shot, their energy slope hardly varies as shown in Fig. 2(a): Th = 2.2(±0.3) MeV for Cu and carbon nanotube (CNT), and 2.3(±0.3) MeV for graphite, respectively
The yields associated to the CNT and graphite targets significantly differ at low intensities
Summary
After the recent successful fast ignition (FI) integrated experiment at ILE, Osaka University [1], ultra high-intensity laser systems with considerable energy have been built for demonstration of FI such as GEKKO-LFEX and Omega-EP. More energetic, 100 kJ-class laser pulses seem to be required for achieving ignition according to current estimates of the laser-to-plasma energy coupling efficiency [1] This poses considerable technological challenges due to the difficulty of developing large optics with high energy tolerance such as compressor gratings. A very thin gold foam material with about 400 nm diameter pores was irradiated on the GEKKO-PW laser light Such nano-structured targets enable a concentration of the electromagnetic field at the target edges and excite “plasmons” around the structure, resulting in an efficient energy transfer from the laser to the material. Several similar studies have shown that targets consisting of aligned nano-tube/wires allow for an enhanced energy coupling [3, 4] These experiments were performed with 30 fs laser systems at lower intensities than ours. It is important to investigate whether these promising results can be extended to the high-intensity picosecond laser-plasma regime
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
