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(IF/P-16) Test of an Indirect Drive Fast Ignition Target Concept

R.B. Stephens1), S.P. Hatchett2), R.E. Turner2), K.A. Tanaka3), R. Kodama3), J.M. Sources4)
1) General Atomics, San Diego, USA
2)Lawrence Livermore National Laboratory, Livermore, Caifornia, USA
3) Institute for Laser Engineering, Osaka University, Osaka, Japan
4) Laboratory for Laser Energetics, University of Rochester, Rochester, New York, USA

Abstract.  A Fast Ignition IFE target must allow a controlled, short path to the assembled fuel mass for the short pulse from the ignitor laser. One can achieve that by protecting one axis of the target from the compression driver and the resulting blowoff with a hollow cone whose tip is near the collapse point of the DT ice shell. Modeling suggests that the presence of the cone substantially changes implosion dynamics: One should achieve the most compact target with an asymmetric drive. There is also a concern that material from the cone might mix into the assembled fuel mass, and hinder ignition. We have tested the model on Omega with an indirect-drive realization of this target concept. Each collapse was radiographed with an x-ray framing camera that took a sequence of 16 x-radiographs. With this we were able to find implosion velocity and diameter, density, and symmetry at stagnation. We also took pictures alternately through different filters to identify any gold contamination in the assembled fuel. Results will be discussed and compared to simulations. *Work done under the auspices of DOE Contracts DE-FG03-01SF22229, W-7405-ENG-48, and with the corporate support of General Atomics.

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IAEA 2003