Stimulated Raman scattering in large plasmas

摘要: In long pulse, high‐energy experiments (4000 J, 2 nsec, 5×1014 W/cm2, 1.064 μm) at the Shiva laser facility, several percent of light has been observed to be Raman scattered. The spectrum Raman‐scattered was measured from 1.48 2.17 μm. scattering occurred principally electron densities much lower than quarter‐critical density. electrons expected in were indirectly these via their bremsstrahlung radiation. Additional show that instability a intensity threshold for longer pusle length and larger spot size. measurements 5320 A irradiated disk target are also reported. near 2λ0 or μm had both red‐ blue‐shifted component. At high intensities, very underdense plasma.