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Direct drive double shell target implosion hydrodynamics on OMEGA

Published online by Cambridge University Press:  07 June 2005

GEORGE A. KYRALA
Affiliation:
Los Alamos National Laboratory, Los Alamos, New Mexico
NORMAN DELAMATER
Affiliation:
Los Alamos National Laboratory, Los Alamos, New Mexico
DOUGLAS WILSON
Affiliation:
Los Alamos National Laboratory, Los Alamos, New Mexico
JOYCE GUZIK
Affiliation:
Los Alamos National Laboratory, Los Alamos, New Mexico
DON HAYNES
Affiliation:
Los Alamos National Laboratory, Los Alamos, New Mexico
MARK GUNDERSON
Affiliation:
Los Alamos National Laboratory, Los Alamos, New Mexico
KENNETH KLARE
Affiliation:
Los Alamos National Laboratory, Los Alamos, New Mexico
ROBERT W. WATT
Affiliation:
Los Alamos National Laboratory, Los Alamos, New Mexico
WILLIAM M. WOOD
Affiliation:
Los Alamos National Laboratory, Los Alamos, New Mexico
WILLIAM VARNUM
Affiliation:
Los Alamos National Laboratory, Los Alamos, New Mexico

Abstract

Imploding indirect-drive double shell targets may provide an alternative, non-cryogenic path to ignition at the National Ignition Facility (NIF). Experiments are being pursued at OMEGA to understand the hydrodynamics of these implosions and the possibility of scaling it to the NIF design. We have used 40 beams from the OMEGA laser to directly drive the capsules, and we have used the remaining 20 beams to backlight the imploding shells from two different directions at multiple times. We will review the recent experiments to measure the hydrodynamics of the targets using two-view X-ray radiography of the capsules. We will present data on measured yields from the targets. We will present a measured time history of the hydrodynamics of the implosion. Experiments were pursued using direct drive in which the M-band effect (experienced in the indirect drive experiments) could be eliminated or controlled. It was learned in the direct drive experiments that the best performing capsules were those that had a thin outer layer of gold. This effectively causes M-band pre-heat effects giving implosion hydrodynamics and performance closer to the indirect drive case. We will review the methods used to radiograph the targets and the techniques used to extract useful information to compare with calculations. The effect of imperfections in the target construction will be shown to be minimal during the initial stage of implosion. The yields from the targets were observed to be uniformly low compared to indirect-drive.

Type
Research Article
Copyright
2005 Cambridge University Press

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Footnotes

This paper was presented at the 28th ECLIM conference in Rome, Italy.

References

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