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SPECIAL AMO/QO PHYSICS COLLOQUIUM


"Progress in Inertial Confinement Fusion experiments on the NIF*"


Dr. Edward I. Moses
Lawrence Livermore National Laboratory, Livermore, CA

ABSTRACT 

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL), operational since March 2009, is making significant strides toward its ignition goal. The facility has demonstrated performance exceeding 1.8 MJ and 500 TW of 3ω light on target far exceeding all other high energy density science (HEDS) facilities making it the preeminent facility for ignition research. The facility has over 60 diagnostic systems operational and has demonstrated flexibility in laser pulse shape and performance to serve the needs of its multiple users including ignition science, HEDS, national security applications, and fundamental science. Progress on ignition continues toward demonstrating thermonuclear burn in the laboratory. Initial experiments have used indirect drive to explore the performance of CH capsules with shaped pulses producing low fuel adiabat implosions. Experiments using surrogate targets optimize shock timing and drive symmetry. Over forty experiments with cryogenic DT layers have explored the performance of ignition implosions. Fuel densities and velocities have been attained within 80% of that required for ignition and core pressures are within a factor of two needed for ignition. Yields are a factor of three to ten below simulation predictions. Possible explanations include low-mode asymmetry and ablation front mix that may be degrading the implosions. Experiments are underway investigating these effects. Recent experiments are investigating higher adiabat implosions that are predicted to be more stable to hydrodynamic instabilities. Initial results indicate that performance is closer to simulation predictions. Experiments using high-density carbon capsules have begun to study alternate ablator implosions. New platforms are being developed for HEDS and fundamental science. Equation-of-state experiments have obtained pressures of over 50 MBars in diamond, conditions never previously encountered in the laboratory and similar to those found in planetary interiors. NIF continues to expand its experimental capabilities. Advanced Radiographic Capability (ARC) is now being installed on NIF for high-energy radiography of imploded cores of ignition targets and for short pulse laserplasma interaction experiments. Other new diagnostics and incremental improvements in laser performance are being planned to continue enhancing the capability of NIF.

*This work performed under the auspices of the U.S. DoE by LLNL (Contract: DE-AC52-07NA27344).



Tuesday, October 29, 2013
MPHY 578, 2:00 p.m.
Hawking Auditorium


Department of Physics and Astronomy
Texas A&M University



Host: Dr. George R. Welch