title: Amplification of light in a plasma by stimulated ion acoustic waves driven by multiple crossing pump beams.
abstract: Experiments demonstrate the amplification of 351 nm laser light in a hot dense plasma similar to those in inertial confinement fusion ignition experiments. A seed beam interacts with one or two counter-propagating pump beams, each with an intensity of 1.2×10(15) W/cm2 at 351 nm, crossing the seed at 24.8° at the position where the flow is Mach 1, allowing resonant stimulation of ion acoustic waves. Results show that the energy and power transferred to the seed are increased with two pumps beyond the level that occurs with a single pump, demonstrating that, under conditions similar to ignition experiments where each beam has a low gain exponent, the total scatter produced by the multiple beams can be significantly larger than that of the individual beams. It is further demonstrated that the amplification is greatly reduced when the pump polarization is orthogonal to the seed, as expected from models of stimulated scatter.
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Kirkwood
authors.forename: P
authors.initials: P
authors.lastname: Michel
authors.forename: R A
authors.initials: RA
authors.lastname: London
authors.forename: D
authors.initials: D
authors.lastname: Callahan
authors.forename: N
authors.initials: N
authors.lastname: Meezan
authors.forename: E
authors.initials: E
authors.lastname: Williams
authors.forename: W
authors.initials: W
authors.lastname: Seka
authors.forename: L
authors.initials: L
authors.lastname: Suter
authors.forename: C
authors.initials: C
authors.lastname: Haynam
authors.forename: O
authors.initials: O
authors.lastname: Landen