Demonstration of the shock-timing technique for ignition targets on the National Ignition Facility
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14645 (United States)
- Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
- Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)
A high-performance inertial confinement fusion capsule is compressed by multiple shock waves before it implodes. To minimize the entropy acquired by the fuel, the strength and timing of those shock waves must be accurately controlled. Ignition experiments at the National Ignition Facility (NIF) will employ surrogate targets designed to mimic ignition targets while making it possible to measure the shock velocities inside the capsule. A series of experiments on the OMEGA laser facility [Boehly et al., Opt. Commun. 133, 495 (1997)] validated those targets and the diagnostic techniques proposed. Quartz was selected for the diagnostic window and shock-velocity measurements were demonstrated in Hohlraum targets heated to 180 eV. Cryogenic experiments using targets filled with liquid deuterium further demonstrated the entire timing technique in a Hohlraum environment. Direct-drive cryogenic targets with multiple spherical shocks were used to further validate this technique, including convergence effects at relevant pressures (velocities) and sizes. These results provide confidence that shock velocity and timing can be measured in NIF ignition targets, allowing these critical parameters to be optimized.
- OSTI ID:
- 21277173
- Journal Information:
- Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 16; ISSN PHPAEN; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Experimental validation of a diagnostic technique for tuning the fourth shock timing on National Ignition Facility
LLE Review 117 (October-December 2008)