Stimulated Raman scattering in inhomogeneous collisional laser-produced plasmas

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.870758· OSTI ID:6684953

Barr, H C; Boyd, T J.M.; Mackwood, A P ^[1]

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1. Department of Physics, University of Essex, Colchester, C04 3SQ (United Kingdom)

Convective gain and absolute growth of stimulated Raman scattering (SRS) are determined for a hot inhomogeneous collisional plasma using an integrated global model that includes the effects of wave propagation and both collisional and Landau damping in a density ramp. This unifies the time asymptotic theory of SRS occurring near the quarter-critical density of the laser light and that occurring at lower densities. The level of collisions has a striking effect on the convective behavior of the instability. When collisions are weak, no significant regime of convective gain exists. In consequence, absolute resonances are very sensitive and susceptible to detuning, particularly so near the quarter-critical density. This is shown to be a key factor in understanding the Raman gap'' seen in experiments. No such gap appears in highly collisional regimes in which the absolute resonances are insensitive and significant convective gain occurs over the whole range of wavelengths.

• OSTI ID: 6684953
• Journal Information: Physics of Plasmas; (United States), Journal Name: Physics of Plasmas; (United States) Vol. 1:4; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340 -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
700350* -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
COLLISIONAL PLASMA
CONVECTIVE INSTABILITIES
DAMPING
HOT PLASMA
INHOMOGENEOUS PLASMA
INSTABILITY
LANDAU DAMPING
LASER-PRODUCED PLASMA
PLASMA
PLASMA INSTABILITY
RAMAN EFFECT
RESONANCE