Hydrodynamic instabilities in beryllium targets for the National Ignition Facility

Beryllium ablators offer higher ablation velocity, rate, and pressure than their carbon-based counterparts, with the potential to increase the probability of achieving ignition at the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)]. We present here a detailed hydrodynamic stability analysis of low (NIF Revision 6.1) and high adiabat NIF beryllium target designs. Our targets are optimized to fully utilize the advantages of beryllium in order to suppress the growth of hydrodynamic instabilities. This results in an implosion that resists breakup of the capsule, and simultaneously minimizes the amount of ablator material mixed into the fuel. We quantify the improvement in stability of beryllium targets relative to plastic ones, and show that a low adiabat beryllium capsule can be at least as stable at the ablation front as a high adiabat plastic target.

[1]  N. Izumi,et al.  Onset of hydrodynamic mix in high-velocity, highly compressed inertial confinement fusion implosions. , 2013, Physical review letters.

[2]  J. Kress,et al.  Calculations of the thermal conductivity of National Ignition Facility target materials at temperatures near 10 eV and densities near 10 g/cc using finite-temperature quantum molecular dynamics , 2011 .

[3]  Casanova,et al.  Kinetic simulation of a collisional shock wave in a plasma. , 1991, Physical review letters.

[4]  K. A. Moreno,et al.  Beryllium Capsule Coating Development for NIF Targets , 2007 .

[5]  Kamel Fezzaa,et al.  Quantitative characterization of inertial confinement fusion capsules using phase contrast enhanced x-ray imaging , 2005 .

[6]  P. Michel,et al.  Hohlraum energetics scaling to 520 TW on the National Ignition Facilitya) , 2013 .

[7]  Jay D. Salmonson,et al.  High-mode Rayleigh-Taylor growth in NIF ignition capsules , 2007 .

[8]  Mark Sherlock,et al.  A review of Vlasov-Fokker-Planck numerical modeling of inertial confinement fusion plasma , 2012, J. Comput. Phys..

[9]  L. J. Atherton,et al.  Point design targets, specifications, and requirements for the 2010 ignition campaign on the National Ignition Facility , 2010 .

[10]  D. Harris,et al.  Ignition target design and robustness studies for the National Ignition Facility , 1996 .

[11]  E. Dewald,et al.  Design of a high-foot high-adiabat ICF capsule for the national ignition facility. , 2013, Physical review letters.

[12]  D. A. Callahan,et al.  Fuel gain exceeding unity in an inertially confined fusion implosion , 2014, Nature.

[13]  Steven W. Haan,et al.  Three-dimensional HYDRA simulations of National Ignition Facility targets , 2001 .

[14]  J. Kilkenny,et al.  Large growth, planar Rayleigh–Taylor experiments on Nova , 1992 .

[15]  O A Hurricane,et al.  High-adiabat high-foot inertial confinement fusion implosion experiments on the national ignition facility. , 2014, Physical review letters.

[16]  Marilyn Schneider,et al.  Analysis of the National Ignition Facility ignition hohlraum energetics experiments a) , 2011 .

[17]  P. Michel,et al.  The role of a detailed configuration accounting (DCA) atomic physics package in explaining the energy balance in ignition-scale hohlraums , 2011 .

[18]  Sir William Thomson F.R.S. XLVI. Hydrokinetic solutions and observations , 1871 .

[19]  Edward I. Moses,et al.  The National Ignition Facility: Ushering in a new age for high energy density science , 2009 .

[20]  M. S. Plesset,et al.  On the Stability of Fluid Flows with Spherical Symmetry , 1954 .

[21]  O. Jones,et al.  Design and simulations of indirect drive ignition targets for NIF , 2004 .

[22]  L. J. Atherton,et al.  A high-resolution integrated model of the National Ignition Campaign cryogenic layered experimentsa) , 2012 .

[23]  J. Lindl Development of the indirect‐drive approach to inertial confinement fusion and the target physics basis for ignition and gain , 1995 .

[24]  G. Magelssen,et al.  Feedout coupling of Richtmyer–Meshkov and Rayleigh–Taylor instabilities in stratified, radiation-driven foils , 1999 .

[25]  Robert B Webster,et al.  Knudsen layer reduction of fusion reactivity. , 2012, Physical review letters.

[26]  O. Landen,et al.  X-ray ablation rates in inertial confinement fusion capsule materials , 2011 .

[27]  J. M. Koning,et al.  Short-wavelength and three-dimensional instability evolution in National Ignition Facility ignition capsule designs , 2011 .

[28]  Roy Kishony,et al.  Ignition condition and gain prediction for perturbed inertial confinement fusion targets , 2001 .

[29]  Lobatchev,et al.  Ablative stabilization of the deceleration phase rayleigh-taylor instability , 2000, Physical review letters.

[30]  Jay D. Salmonson,et al.  Simulations of high-mode Rayleigh-Taylor growth in NIF ignition capsules , 2007 .

[31]  R. B. Stephens,et al.  Inhomogeneous Copper Diffusion in NIF Beryllium Ablator Capsules , 2013 .

[32]  R J Wallace,et al.  Observation of high soft x-ray drive in large-scale hohlraums at the National Ignition Facility. , 2010, Physical review letters.

[33]  Jay D. Salmonson,et al.  Optimized beryllium target design for indirectly driven inertial confinement fusion experiments on the National Ignition Facility , 2014 .

[34]  Jason C. Cooley,et al.  Fabrication of Beryllium Capsules with Copper-Doped Layers for NIF Targets: A Progress Report , 2006 .

[35]  O. Landen,et al.  An in-flight radiography platform to measure hydrodynamic instability growth in inertial confinement fusion capsules at the National Ignition Facility , 2014 .

[36]  E. Meshkov Instability of the interface of two gases accelerated by a shock wave , 1969 .

[37]  John Lindl,et al.  Review of the National Ignition Campaign 2009-2012 , 2014 .

[38]  Stephen E. Bodner,et al.  Rayleigh-Taylor Instability and Laser-Pellet Fusion , 1974 .

[39]  Gilbert W. Collins,et al.  Experimental investigation of bright spots in broadband, gated x-ray images of ignition-scale implosions on the National Ignition Facility , 2013 .

[40]  J. Moody,et al.  X-ray conversion efficiency in vacuum hohlraum experiments at the National Ignition Facility , 2012 .

[41]  G. Taylor The instability of liquid surfaces when accelerated in a direction perpendicular to their planes. I , 1950, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[42]  Dan J. Thoma,et al.  The development and advantages of beryllium capsules for the National Ignition Facility , 1998 .

[43]  Jay D. Salmonson,et al.  Increasing robustness of indirect drive capsule designs against short wavelength hydrodynamic instabilities , 2004 .

[44]  Steven W. Haan,et al.  Nova indirect drive RayleighTaylor experiments with beryllium , 2002 .

[45]  Steven W. Haan,et al.  Modeling of Nova indirect drive Rayleigh–Taylor experiments , 1994 .

[46]  O. Landen,et al.  The physics basis for ignition using indirect-drive targets on the National Ignition Facility , 2004 .

[47]  Steven W. Haan,et al.  NIF capsule design update , 1997 .

[48]  Stephanie B. Hansen,et al.  Equation of state, occupation probabilities and conductivities in the average atom Purgatorio code , 2006 .

[49]  W. Goldstein Science of Fusion Ignition on NIF , 2012 .

[50]  V N Goncharov,et al.  Demonstration of the improved rocket efficiency in direct-drive implosions using different ablator materials. , 2013, Physical review letters.