National Ignition Facility targets driven at high radiation temperature: Ignition, hydrodynamic stability, and laser–plasma interactions

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Abstract
A target design driven indirectly to ignition at a radiation temperature of 350 eV for the National Ignition Facility (NIF) is reported in integrated radiation-hydrodynamic simulations which detail the necessary specifications to achieve ignition and burn. The target is further analyzed to determine its hydrodynamic stability as well as its vulnerability to laser–plasma interactions. This target shows enhanced hydrodynamic stability over targets previously designed at lower radiation temperatures [S. W. Haan, S. M. Pollaine, J. D. Lindl et al., Phys. Plasmas 2, 2480 (1995); W. J. Krauser, N. M. Hoffman, D. C. Wilson et al., ibid.3, 2084 (1996); D. C. Wilson, P. A. Bradley, N. M. Hoffman et al., ibid.5, 1953 (1998); P. A. Bradley and D. C. Wilson, ibid.6, 4293 (1999)]. To control laser–plasma instabilities, both polarization and temporal smoothing of the spatially smoothed NIF laser beams is necessary. Analyses of laser scatter in target blow-off at peak power demonstrate saturation in both the 300 and 350 eV designs by nonlinear processes such as rescatter of the scattered laser light and the Langmuir decay instability.