Early-Time Symmetry Tuning in the Presence of Cross-Beam Energy Transfer in ICF Experiments on the National Ignition Facility

• DOI: 10.1103/physrevlett.111.235001
• Publication Date: 2013-12-02T22:54:08Z
• Authors: E. L. Dewald; J. L. Milovich; P. Michel; O. L. Landen; J. L. Kline; S. Glenn; O. Jones; D. H. Kalantar; A. Pak; H. F. Robey; G. A. Kyrala; L. Divol; L. R. Benedetti; J. Holder; K. Widmann; A. Moore; M. B. Schneider; T. Döppner; R. Tommasini; D. K. Bradley; P. Bell; B. Ehrlich; C. A. Thomas; M. Shaw; C. Widmayer; D. A. Callahan; N. B. Meezan; R. P. J. Town; A. Hamza; B. Dzenitis; A. Nikroo; K. Moreno; B. Van Wonterghem; A. J. Mackinnon; S. H. Glenzer; B. J. MacGowan; J. D. Kilkenny; M. J. Edwards; L. J. Atherton; E. I. Moses
• Keywords: Hohlraum; Implosion; National Ignition Facility

On the National Ignition Facility, hohlraum-driven implosion symmetry is tuned using cross-beam energy transfer (CBET) during peak power, which controlled by applying a wavelength separation between cones of laser beams. In this Letter, we present early-time measurements instantaneous soft x-ray drive at capsule reemission spheres, show that also leads to significant CBET first shock, even though intensities are 30× smaller than peak. We demonstrate resulting early P2/P0 asymmetry can be minimized and <1% accuracy (well within ±7.5% requirement for ignition) varying relative input powers different These experiments provide time-resolved 2 ns drive, in good agreement with radiation-hydrodynamics calculations including linear model.