Stimulated Brillouin backscatter of a short-pulse laser

Journal Article · Fri Sep 01 04:00:00 EDT 1995 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871126· OSTI ID:115896

Hinkel, D E; Williams, E A; Berger, R L ^[1]

---

1. Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)

Stimulated Brillouin backscattering (SBBS) from a short-pulse laser, where the pulse length is short compared to the plasma length, is found to be qualitatively different than in the long pulse regime, where the pulse length is long compared to the plasma length. After an initial transient of order the laser pulse length transit time, the instability reaches a steady state in the variables {ital x}{sup {prime}}={ital x}{minus}{ital V}{sub {ital g}}{ital t}, {ital t}{sup {prime}}={ital t}, where {ital V}{sub {ital g}} is the pulse group velocity. In contrast, SBBS in a long pulse can be absolutely unstable and grows indefinitely, or until nonlinearities intervene. The motion of the laser pulse induces Doppler related effects that substantially modify the backscattered spectrum at higher intensities, where the instability is strongly coupled (i.e., has a growth rate large compared to the ion acoustic frequency). {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

• Research Organization: Lawrence Livermore National Laboratory
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 115896
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 9 Vol. 2; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BACKSCATTERING
BRILLOUIN EFFECT
DOPPLER EFFECT
INSTABILITY GROWTH RATES
ION ACOUSTIC WAVES
LASER RADIATION
LIGHT SCATTERING
PULSED IRRADIATION