Stimulated Brillouin backscattering from underdense expanding plasmas in a regime of strong filamentation

Anno: 1999

Autori: Giulietti A., Macchi A., Schifano E., Biancalana V., Danson C., Giulietti D., Gizzi LA., Willi O.

Affiliazione autori: CNR, Ist Fis Atom & Mol, I-56127 Pisa, Italy;
Scuola Normale Super Pisa, Pisa, Italy;
Univ Pisa, Ist Nazl Fis Mat, Sez A, Pisa, Italy;
Univ Siena, Dipartimento Fis, I-53100 Siena, Italy;
Rutherford Appleton Lab, Cent Laser Facil, Chilton, England;
Univ Pisa, Dipartimento Fis, Pisa, Italy;
Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London, England

Abstract: Stimulated Brillouin backscattering (B-SBS) from delayed interaction with a preformed, long scale-length expanding plasma was experimentally investigated in a regime favorable to strong self-focusing (SF) and filamentation. An extremely low backscattering reflectivity (of the order of 10(-4)) was measured and anomalous time-resolved spectra were observed. Spectral and temporal features of the reflectivity suggest a strong effect of SF on B-SBS: In the early phase of the interaction SF lowers the B-SBS threshold and possibly leads to rapid saturation, while in the late phase there is a substantial decoupling of the SBS active regions from the plasma bulk due to their motion towards the laser beam. This motion is attributed to a moving focus effect driven by ponderomotive SF.

Giornale/Rivista: PHYSICAL REVIEW E

Volume: 59 (1)      Da Pagina: 1038  A: 1046

Parole chiavi: laser hot-spots; scattering; light; propagation; waves
DOI: 10.1103/PhysRevE.59.1038

Citazioni: 22
dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2024-03-24
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