Laser Smoothing and Imprint Reduction with a Foam Layer in the Multikilojoule Regime

S. Depierreux (1) , C. Labaune (2) , D. Michel (3) , C. Stenz (4) , P. Nicolaï (4) , M. Grech (2) , G. Riazuelo (5) , S. Weber (6, 7) , C. Riconda (2) , V. Tikhonchuk (4) , P. Loiseau (8) , N. Borisenko (9) , W. Nazarov (10) , S. Hüller (11) , D. Pesme (11) , M. Casanova (12) , J. Limpouch (13) , C. Meyer (14) , P. Di-Nicola , R. Wrobel (1) , E. Alozy , P. Romary , G. Thiell , G. Soullié , C. Reverdin , B. Villette

1 DAM/DIF - DAM Île-de-France
2 LULI - Laboratoire pour l'utilisation des lasers intenses
3 LERMAB - Laboratoire d’Etude et de Recherche sur le Matériau Bois
4 CELIA - Centre d'Etudes Lasers Intenses et Applications
5 DPTA - Département de Physique Théorique et Appliquée
6 IJL - Institut Jean Lamour
7 LIEN - Laboratoire d'Instrumentation Electronique de Nancy
8 LCMCP (site Paris VI) - Laboratoire de Chimie de la Matière Condensée de Paris (site Paris VI)
9 LPI RAS - P. N. Lebedev Physical Institute of the Russian Academy of Sciences [Moscow]
10 University of St Andrews [Scotland]
11 CPHT - Centre de Physique Théorique [Palaiseau]
12 CEA-DAM - Centre d'Études de Limeil-Valenton
13 CTU - Czech Technical University in Prague
14 LCE - Laboratoire Chrono-environnement (UMR 6249)

This Letter presents first experimental results of the laser imprint reduction in fusion scale plasmas using a low-density foam layer. The experiments were conducted on the LIL facility at the energy level of 12 kJ with millimeter-size plasmas, reproducing the conditions of the initial interaction phase in the direct-drive scheme. The results include the generation of a supersonic ionization wave in the foam and the reduction of the initial laser fluctuations after propagation through 500  μm of foam with limited levels of stimulated Brillouin and Raman scattering. The smoothing mechanisms are analyzed and explained.

Domaines: Physique [physics]

S. Depierreux, C. Labaune, D. Michel, C. Stenz, P. Nicolaï, et al.. Laser Smoothing and Imprint Reduction with a Foam Layer in the Multikilojoule Regime. Physical Review Letters, 2009, 102 (19), pp.195005. ⟨10.1103/PhysRevLett.102.195005⟩. ⟨hal-04506287⟩