Stimulated Raman backscattering instability in short pulse laser interaction with helium gas

Journal Article · Wed May 01 04:00:00 EDT 1996 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871688· OSTI ID:282889

Malka, V; De Wispelaere, E; Marques, J R; Bonadio, R; Amiranoff, F ^[1]; Blasco, F; Stenz, C ^[2]; Mounaix, P ^[3]; Grillon, G; Nibbering, E ^[4]

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1. Laboratoire pour lUtilisation des Lasers Intenses, Ecole Polytechnique, 91128 Palaiseau Cedex (France)
2. Groupe de Recherches sur lEnergetique des Milieux Ionises, Universite dOrleans, 45067 Orleans Cedex 2 (France)
3. Centre de Physique Theorique, Ecole Polytechnique, 91128 Palaiseau (France)
4. Laboratoire dOptique Appliquee, Ecole Nationale Superieure des Techniques Avancees, 91120 Palaiseau (France)

Experimental and theoretical results on the stimulated Raman backscattering (SRS) reflectivity of a short laser pulse (120 fs) interaction with an optically ionized helium gas are presented. The reflectivity is measured as a function of the gas pressure from 1 to 100 Torr. A monodimensional (1-D) theoretical model, including the refraction induced during the ionization process, describes the dependence of the SRS reflectivity with the gas pressure and explains its maximum at around 35 Torr. In the very low pressure case ({lt}15 Torr), the radial ponderomotive force expels the electrons out of the propagation region before the laser pulse reaches its peak intensity and significantly reduces the observed reflectivity. A 1-D hydrodynamic calculation, included in the model, describes this density depletion and a good agreement is obtained between theory and experiments in the whole range of pressures. {copyright} {ital 1996 American Institute of Physics.}

• OSTI ID: 282889
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 3; ISSN 1070-664X; ISSN PHPAEN
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BACKSCATTERING
BEAM-PLASMA SYSTEMS
HELIUM
IONIZED GASES
LASER RADIATION
LASER-PRODUCED PLASMA
PARAMETRIC INSTABILITIES
PHOTON-ATOM COLLISIONS
PLASMA INSTABILITY
PONDEROMOTIVE FORCE
RAMAN EFFECT