Nanostructure array plasmas generated by femtosecond pulses at highly relativistic intensities

R. HOLLINGER; Y. WONG; S. WONG; A. ROCKWOOD; J. GLASBY; V. SHLYAPTSEV; J. J. ROCCA; M. G. CAPELUTO; V. KAYMAK; A. PUKHOV

Conferencia; 59th Annual Meeting of the APS Division of Plasma Physics; 2017

The irradiation of high aspect ratio ordered nanostructure arrays with ultra-high contrast femtosecond laser pulses of relativistic intensity provides a unique combination of nearly complete optical absorption and drastically enhanced light penetration into near-solid density targets. This allows the material to be volumetrically heated deep into the ultra-high energy density regime .In previous experiments we have shown that irradiation of Ni and Au nanostructures with femtosecond pulses focused to an intensity of 5x1018 Wcm−2 generate multi-KeV near solid density plasmas in which atoms are ionized to the Ni+26 and Au+52 charge states. Here we present the first results of the Irradiation of nanostructure arrays with highly relativistic pulses of intensities up to 5e21Wcm−2 . Silver and Rhodium nanowire arrays were irradiated with frequency-doubled pulses of 30 fs duration from a petawatt-class Ti:Sa laser. Time integrated x-ray spectra show the presence of He-like and Li-like emission. Results of experiments conducted with a variety of different nanowires diameters with a range of interwire spacings will be presented and compared to the result of 3D particlein-cell-simulations.