Investigation of stimulated raman scattering using short-pulse diffraction limited laser beam near the instability threshold

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Lasers and Particle Beams

OSTI ID:960939

Kline, John L ^[1]; Montgomery, David S ^[1]; Flippo, Kirk A ^[1]; Rose, Harvey A ^[1]; Yin, L ^[1]; Albright, B J ^[1]; Johnson, R P ^[1]; Shimada, T ^[1]; Bowers, K ^[1]; Rousseaux, C ^[2]; Tassin, V ^[2]; Baton, S D ^[3]; Amiranoff, F ^[3]; Hardin, R A ^[4]

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1. Los Alamos National Laboratory
2. CEA
3. FRANCE
4. WEST VIRGINIA UNIV

Short pulse laser plasma interaction experiments using diffraction limited beams provide an excellent platform to investigate the fundamental physics of Stimulated Raman Scattering. Detailed understanding of these laser plasma instabilities impacts the current inertial confinement fusion ignition designs and could potentially impact fast ignition when higher energy lasers are used with longer pulse durations ( > 1 kJ and> 1 ps). Using short laser pulses, experiments can be modeled over the entire interaction time of the laser using particle-in-cell codes to validate our understanding quantitatively. Experiments have been conducted at the Trident laser facility and the LULI (Laboratoire pour l'Utilisation des Lasers Intenses) to investigate stimulated Raman scattering near the threshold of the instability using 527 nm and 1059 nm laser light respectively with 1.5-3.0 ps pulses. In both experiments, the interaction beam was focused into a pre-ionized He gas-jet plasma. Measurements of the reflectivity as a function of intensity and k{lambda}{sub D} were completed at the Trident laser facility. At LULI, a 300 fs Thomson scattering probe is used to directly measure the density fluctuations of the driven electron plasma and ion acoustic waves. Work is currently underway comparing the results of the experiments with simulations using the VPIC [K. J. Bowers, et at., Phys. Plasmas, 15 055703 (2008)] particle-in-cell code. Details of the experimental results are presented in this manuscript.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: DOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 960939
• Report Number(s): LA-UR-08-06659; LA-UR-08-6659
• Journal Information: Lasers and Particle Beams, Journal Name: Lasers and Particle Beams
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAMS
DENSITY
DIFFRACTION
ELECTRONS
ENERGY
FLUCTUATIONS
FUNCTIONS
IGNITION
INERTIAL CONFINEMENT
INSTABILITY
INTERACTIONS
ION ACOUSTIC WAVES
LASERS
PHYSICS
PLASMA
PULSES
RAMAN EFFECT
REFLECTIVITY
SCATTERING
THOMSON SCATTERING