Measurements of parametric instabilities at laser intensities relevant to strong shock generation

0490069 - FZÚ 2019 RIV US eng J - Journal Article
Cristoforetti, G. - Antonelli, L. - Atzeni, S. - Baffigi, F. - Barbato, F. - Batani, D. - Boutoux, G. - Colaïtis, A. - Dostál, Jan - Dudžák, Roman - Juha, Libor - Koester, P. - Marocchino, A. - Mancelli, D. - Nicolai, Ph. - Renner, Oldřich - Santos, J.J. - Schiavi, A. - Skoric, M.M. - Šmíd, Michal - Straka, Petr - Gizzi, L.A.
Measurements of parametric instabilities at laser intensities relevant to strong shock generation.
Physics of Plasmas. Roč. 25, č. 1 (2018), s. 1-12, č. článku 012702. ISSN 1070-664X. E-ISSN 1089-7674
R&D Projects: GA MŠMT EF15_008/0000162; GA ČR GA17-05076S
EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE; European Commission(XE) 284464 - LASERLAB-EUROPE
Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162
Institutional support: RVO:68378271
Keywords : stimulated Raman-scattering * inhomogeneous plasmas * Brillouin-scattering * 2-Plasmon Decay * Prague Asterix Laser System facility
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 1.913, year: 2018

Parametric instabilities at laser intensities in the range (2–6) x 1015 W/cm2 (438 nm, 250 ps, 100–300 J) have been investigated in planar geometry at the Prague Asterix Laser System facility via calorimetry and spectroscopy. Experimental data show that Stimulated Brillouin Scattering (SBS) is more effective than Stimulated Raman Scattering (SRS) in degrading laser-plasma coupling, therefore reducing the energy available for the generation of the shock wave. The level of the SBS backscatter and laser reflection is found to be in the range between 3% and 15% of the incident laser energy, while Backward SRS (BRS) reflectivity ranges between 0.02% and 0.2%, depending on the delay between the pulses. Half-integer harmonic emission is observed and provides a signatureof Two Plasmon Decay (TPD) occurring around the quarter of the critical density. Our measurements indicate, besides others, that hot electrons are predominantly produced by SRS rather than TPD.
Permanent Link: http://hdl.handle.net/11104/0284364