Dynamic hohlraum radiation hydrodynamics

Journal Article · Mon May 15 00:00:00 EDT 2006 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2177640· OSTI ID:20783149

Bailey, J E; Chandler, G A; Slutz, S A; Rochau, G A; Cooper, G; Lake, P W; Leeper, R J; Lemke, R; Mehlhorn, T A; Nash, T J; Nielsen, D S; Peterson, K L; Ruiz, C L; Varnum, W ^[1]; Mancini, R C; Buris-Mog, T J ^[2]; Bump, M; Dunham, G; Moore, T C ^[3]; Golovkin, I ^[4]

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1. Sandia National Laboratories, Albuquerque, New Mexico 87185-1196 (United States)
2. University of Nevada, Reno, Nevada 89557 (United States)
3. K-tech Corporation, Albuquerque, New Mexico 87185 (United States)
4. Prism Computational Sciences, Madison, Wisconsin 53703 (United States)

Z-pinch dynamic hohlraums are a promising indirect-drive inertial confinement fusion approach. Comparison of multiple experimental methods with integrated Z-pinch/hohlraum/capsule computer simulations builds understanding of the hohlraum interior conditions. Time-resolved x-ray images determine the motion of the radiating shock that heats the hohlraum as it propagates toward the hohlraum axis. The images also measure the radius of radiation-driven capsules as they implode. Dynamic hohlraum LASNEX [G. Zimmerman and W. Kruer, Comments Plasma Phys. Control. Fusion 2, 85 (1975)] simulations are found to overpredict the shock velocity by {approx}20-40%, but simulated capsule implosion trajectories agree reasonably well with the data. Measurements of the capsule implosion core conditions using time- and space-resolved Ar tracer x-ray spectroscopy and the fusion neutron yield provide additional tests of the integrated hohlraum-implosion system understanding. The neutron yield in the highest performing CH capsule implosions is {approx}20-30% of the yield calculated with unperturbed 2D LASNEX simulations. The emissivity-averaged electron temperature and density peak at approximately 900 eV and 4x10{sup 23} cm{sup -3}, respectively. Synthetic spectra produced by postprocessing 1D LASNEX capsule implosion simulations possess spectral features from H-like and He-like Ar that are similar in duration to the measured spectra. However, the simulation emissivity-averaged density peaks at a value that is four times lower than the experiment, while the temperature is approximately 1.6 times higher. The agreement with the capsule trajectory measurements and the ability to design capsule implosions that routinely produce implosion cores hot and dense enough to emit fusion neutrons and Ar spectra are evidence for a respectable degree of dynamic hohlraum understanding. The hohlraum shock velocity and implosion core discrepancies imply that calculations of the hohlraum radiation driving capsule implosions require further refinement.

• OSTI ID: 20783149
• Journal Information: Physics of Plasmas, Vol. 13, Issue 5; Other Information: DOI: 10.1063/1.2177640; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CAPSULES
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
ELECTRON TEMPERATURE
EMISSIVITY
EV RANGE
HYDRODYNAMICS
ICF DEVICES
IMPLOSIONS
INERTIAL CONFINEMENT
ION TEMPERATURE
NEUTRONS
PLASMA
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA SIMULATION
SHOCK WAVES
TIME RESOLUTION
X RADIATION
X-RAY SPECTROSCOPY