Measurements of laser-plasma instability relevant to ignition hohlraums

• DOI: 10.1063/1.872328
• Publication Date: 2002-07-26T12:39:37Z
• Authors: Juan C. Fernández; Bruno S. Bauer; James A. Cobble; D. F. DuBois; George A. Kyrala; D. S. Montgomery; Harvey A. Rose; H. X. Vu; Robert G. Watt; Bernhard H. Wilde; Mark D. Wilke; William M. Wood; Bruce H. Failor; R. Kirkwood; B. J. MacGowan
• Keywords: Hohlraum; National Ignition Facility; Saturation (graph theory)

The potential for laser-plasma instability is a serious concern indirect-drive inertial confinement fusion (ICF), where laser beams illuminate the interior of cavity (called hohlraum) to produce x-rays imploding capsule symmetrically. speckled nature used in ICF an important factor processes. For example, models which calculate spatial growth convective by properly accounting speckles successfully predict observed onsets backscattering due stimulated Brillouin and Raman scattering instabilities (SBS SRS). Assuming pump depletion as only saturation mechanism these results very large predicted levels SBS SRS from long-scale plasmas expected ignition hohlraums. However, studied Nova Trident lasers [E. M. Campbell, Rev. Sci. Instrum. 57, 2101 (1986) N. K. Moncur et al., Appl. Opt. 34, 4274 (1995)], are saturate much below depletion. While not understood at present, observations qualitatively understood.