Evidence of plasma fluctuations and their effect on the growth of stimulated Brillouin and stimulated Raman scattering in laser plasmas

Journal Article · Fri May 01 04:00:00 EDT 1998 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.872868· OSTI ID:627793

Montgomery, D S; Afeyan, B B; Cobble, J A; Fernandez, J C; Wilke, M D; Glenzer, S H; Kirkwood, R K; MacGowan, B J; Moody, J D; Lindman, E L; Munro, D H; Wilde, B H; Rose, H A; Dubois, D F; Bezzerides, B; Vu, H X ^[1]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico87545 (United States)

The reflectivity levels of stimulated Brillouin scattering (SBS) in recent large scale length laser plasma experiments is much lower than expected for conditions where the convective gain exponent is expected to be large [J. C. Fern{acute a}ndez {ital et al.}, Phys. Plasmas {bold 4}, 1849 (1997)]. Long-wavelength velocity fluctuations caused during the plasma formation process, or by parametric instabilities themselves, have been proposed as a mechanism to detune SBS in these experiments and reduce its gain [W. L. Kruer {ital et al.}, Phys. Plasmas {bold 3}, 382 (1996); H. A. Rose, Phys. Plasmas {bold 4}, 437 (1997)]. Evidence of large-velocity fluctuation levels is found in the time-resolved SBS spectra from these experiments, and correlates with observed changes in the reflectivity of both SBS and stimulated Raman scattering (SRS). Evidence of fluctuations that increase with increasing plasma density is presented, and their effect on the growth of parametric instabilities is discussed. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 627793
• Report Number(s): CONF-971103--
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 5; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAM-PLASMA SYSTEMS
BRILLOUIN EFFECT
FLUCTUATIONS
LASER-PRODUCED PLASMA
LIGHT SCATTERING
PLASMA DENSITY
RAMAN EFFECT
REFLECTIVITY