Implementation of a near backscattering imaging system on the National Ignition Facility

A near backscattering imaging diagnostic system is being implemented on the first quad of beams on the National Ignition Facility. This diagnostic images diffusing scatter plates, placed around the final focus lenses on the National Ignition Facility target chamber, to quantitatively measure the fraction of light backscattered outside of the focusing cone angle of incident laser beam. A wide-angle imaging system relays an image of light scattered outside the lens onto a gated charge coupled device camera, providing 3 mm resolution over a 2 m field of view. To account for changes of the system throughput due to exposure to target debris the system will be routinely calibrated in situ at 532 and 355 nm using a dedicated pulsed laser source.

[1]  S. Glenzer.  Electronic property measurements of solid density plasmas with x-ray scattering , 2003 .

[2]  F. D. Lee,et al.  Full aperture backscatter station measurement system on the National Ignition Facility , 2004 .

[3]  J. Moody,et al.  Imaging backscattered and near to backscattered light in ignition scale plasmas (invited) , 1997 .

[4]  J Schein,et al.  Radiation-driven hydrodynamics of high- hohlraums on the national ignition facility. , 2005, Physical review letters.

[5]  P. Bell,et al.  Calibration facilities at Bechtel Nevada–Livermore operations (abstract) , 2001 .

[6]  E. Campbell.  Recent results from the Nova program at LLNL , 1991 .

[7]  J. D. Moody,et al.  Laser–plasma interactions in ignition‐scale hohlraum plasmas , 1996 .

[8]  Edward I. Moses,et al.  The National Ignition Facility: enabling fusion ignition for the 21st century , 2004 .

[9]  E. Michael Campbell,et al.  The National Ignition Facility - applications for inertial fusion energy and high-energy-density science , 1999 .

[10]  J. Moody,et al.  Calibration of initial measurements from the full aperture backscatter system on the National Ignition Facility , 2004 .

[11]  A. B. Langdon,et al.  On the dominant and subdominant behavior of stimulated Raman and Brillouin scattering driven by nonuniform laser beams , 1998 .

[12]  R. Kirkwood,et al.  Full-aperture backscatter measurements on the National Ignition Facility , 2004 .

[13]  Joshua E. Rothenberg,et al.  Hohlraum energetics with smoothed laser beams , 2000 .