Low Fuel Convergence Path to Direct-Drive Fusion Ignition.

A new class of inertial fusion capsules is presented that combines multishell targets with laser direct drive at low intensity (2.8×10^{14}  W/cm^{2}) to achieve robust ignition. The targets consist of three concentric, heavy, metal shells, enclosing a volume of tens of μg of liquid deuterium-tritium fuel. Ignition is designed to occur well "upstream" from stagnation, with minimal pusher deceleration to mitigate interface Rayleigh-Taylor growth. Laser intensities below thresholds for laser plasma instability and cross beam energy transfer facilitate high hydrodynamic efficiency (∼10%).

[1]  J. Nuckolls,et al.  Laser Compression of Matter to Super-High Densities: Thermonuclear (CTR) Applications , 1972, Nature.

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

[3]  N. Johnson,et al.  Equilibrium ignition for ICF capsules , 2008 .

[4]  Ronald C. Kirkpatrick,et al.  The physics of DT ignition in small fusion targets , 1981 .

[5]  G. Dimonte.  Dependence of turbulent Rayleigh-Taylor instability on initial perturbations. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[6]  Peter A. Amendt,et al.  Assessing the prospects for achieving double-shell ignition on the National Ignition Facility using vacuum hohlraums , 2007 .

[7]  Peter A. Amendt,et al.  Indirect-Drive Noncryogenic Double-Shell Ignition Targets for the National Ignition Facility: Design and Analysis , 2001 .

[8]  L. J. Atherton,et al.  Progress Towards Ignition on the National Ignition Facility , 2013 .

[9]  M. V. Dyke,et al.  The converging shock wave from a spherical or cylindrical piston , 1982, Journal of Fluid Mechanics.

[10]  Guy Dimonte,et al.  Nonlinear evolution of the Rayleigh–Taylor and Richtmyer–Meshkov instabilities , 1998 .

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

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

[13]  R. S. Cooper,et al.  Structured fusion target designs , 1975 .

[14]  H. Bosch,et al.  ERRATUM: Improved formulas for fusion cross-sections and thermal reactivities , 1992 .