Interaction physics for the shock ignition scheme of inertial confinement fusion targets

This paper presents an analysis of laser–plasma interaction risks of the shock ignition (SI) scheme and experimental results under conditions relevant to the corona of a compressed target. Experiments are performed on the LIL facility at the 10 kJ level, on the LULI 2000 facility with two beams at the kJ level and on the LULI 6-beam facility with 100 J in each beam. Different aspects of the interaction of the SI pulse are studied exploiting either the flexibility of the LULI 6-beam facility to produce a very high intensity pulse or the high energy of the LIL to produce long and hot plasmas. A continuity is found allowing us to draw some conclusions regarding the coupling quality and efficiency of the SI spike pulse. It is shown that the propagation of the SI beams in the underdense plasma present in the corona of inertial confinement fusion targets could strongly modify the initial spot size of the beam through filamentation. Detailed experimental studies of the growth and saturation of backscattering instabilities in these plasmas indicate that significant levels of stimulated scattering reflectivities (larger than 40%) may be reached at least for some time during the SI pulse.

[1]  O. Klimo,et al.  Laser plasma interaction studies in the context of shock ignition—Transition from collisional to collisionless absorption , 2011 .

[2]  Vladimir T. Tikhonchuk,et al.  Particle-in-cell simulations of laser–plasma interaction for the shock ignition scenario , 2010 .

[3]  Andrew J. Schmitt,et al.  Shock ignition target design for inertial fusion energy , 2010 .

[4]  P. B. Radha,et al.  Advanced-ignition-concept exploration on OMEGA , 2009 .

[5]  S Depierreux,et al.  Effect of the laser wavelength on the saturated level of stimulated Brillouin scattering. , 2009, Physical review letters.

[6]  L. Perkins,et al.  Shock ignition: a new approach to high gain inertial confinement fusion on the national ignition facility. , 2009, Physical review letters.

[7]  E Alozy,et al.  Laser smoothing and imprint reduction with a foam layer in the multikilojoule regime. , 2009, Physical review letters.

[8]  V. Tikhonchuk,et al.  Coherent forward stimulated-brillouin scattering of a spatially incoherent laser beam in a plasma and its effect on beam spray. , 2008, Physical review letters.

[9]  L. Perkins,et al.  Shock ignition of thermonuclear fuel with high areal density. , 2006, Physical review letters.

[10]  P. Masson-Laborde,et al.  Modeling parametric scattering instabilities in large-scale expanding plasmas , 2006 .

[11]  H. Rose,et al.  How much laser power can propagate through fusion plasma? , 2005, physics/0512271.

[12]  C. Labaune,et al.  Modeling of imaging diagnostics for laser plasma interaction experiments with the code PARAX , 2005 .

[13]  P. Michel,et al.  Laser–plasma interaction experiments in the context of inertial fusion , 2004 .

[14]  S. Depierreux,et al.  Thomson-scattering study of the subharmonic decay of ion-acoustic waves driven by the Brillouin instability. , 2004, Physical review letters.

[15]  J. Meyer-ter-Vehn,et al.  The physics of inertial fusion - Hydrodynamics, dense plasma physics, beam-plasma interaction , 2004 .

[16]  R. S. Craxton,et al.  Laser-plasma interactions in long-scale-length plasmas under direct-drive National Ignition Facility conditions , 1999 .

[17]  A. Schmitt,et al.  Time-dependent filamentation and stimulated Brillouin forward scattering in inertial confinement fusion plasmas , 1998 .

[18]  Guy Schurtz,et al.  Shock ignition: an alternative scheme for HiPER , 2008 .

[19]  Gregory A. Moses,et al.  Inertial confinement fusion , 1982 .