title: Laser smoothing and imprint reduction with a foam layer in the multikilojoule regime.
abstract: 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 mum of foam with limited levels of stimulated Brillouin and Raman scattering. The smoothing mechanisms are analyzed and explained.
authors.affiliation: CEA, DAM, DIF, F-91297 Arpajon, France.
authors.forename: S
authors.initials: S
authors.lastname: Depierreux
authors.forename: C
authors.initials: C
authors.lastname: Labaune
authors.forename: D T
authors.initials: DT
authors.lastname: Michel
authors.forename: C
authors.initials: C
authors.lastname: Stenz
authors.forename: P
authors.initials: P
authors.lastname: Nicolaï
authors.forename: M
authors.initials: M
authors.lastname: Grech
authors.forename: G
authors.initials: G
authors.lastname: Riazuelo
authors.forename: S
authors.initials: S
authors.lastname: Weber
authors.forename: C
authors.initials: C
authors.lastname: Riconda
authors.forename: V T
authors.initials: VT
authors.lastname: Tikhonchuk
authors.forename: P
authors.initials: P
authors.lastname: Loiseau
authors.forename: N G
authors.initials: NG
authors.lastname: Borisenko
authors.forename: W
authors.initials: W
authors.lastname: Nazarov
authors.forename: S
authors.initials: S
authors.lastname: Hüller
authors.forename: D
authors.initials: D
authors.lastname: Pesme
authors.forename: M
authors.initials: M
authors.lastname: Casanova
authors.forename: J
authors.initials: J
authors.lastname: Limpouch
authors.forename: C
authors.initials: C
authors.lastname: Meyer
authors.forename: P
authors.initials: P
authors.lastname: Di-Nicola
authors.forename: R
authors.initials: R
authors.lastname: Wrobel
authors.forename: E
authors.initials: E
authors.lastname: Alozy
authors.forename: P
authors.initials: P
authors.lastname: Romary
authors.forename: G
authors.initials: G
authors.lastname: Thiell
authors.forename: G
authors.initials: G
authors.lastname: Soullié
authors.forename: C
authors.initials: C
authors.lastname: Reverdin
authors.forename: B
authors.initials: B
authors.lastname: Villette