51st Annual Meeting of the APS Division of Plasma Physics
Volume 54, Number 15
Monday–Friday, November 2–6, 2009;
Atlanta, Georgia
Session NI2: ICF Capsules and Rayleigh-Taylor Instability
9:30 AM–12:30 PM,
Wednesday, November 4, 2009
Room: Centennial I
Chair: David Meyerhofer, University of Rochester
Abstract ID: BAPS.2009.DPP.NI2.2
Abstract: NI2.00002 : Shock-Tuned Cryogenic DT Implosion Performance on OMEGA
10:00 AM–10:30 AM
Preview Abstract
Abstract
Author:
T.C. Sangster
(Laboratory for Laser Energetics, U. of Rochester)
Cryogenic-target-compression experiments with low-adiabat (\textit{$\alpha $} $\sim $ 1 to 3)
continuous and multiple-picket-drive pulses are performed on the OMEGA laser
to understand the physics of fuel assembly in inertial confinement fusion.
Continuous-drive-pulse designs require accurate modeling of the compression
wave generated by the gradual rise in laser intensity. Uncertainties in the
ablator/fuel equation-of-state modeling and laser coupling can lead to
uncertainties in the predicted shock coalescence and fuel adiabat. The
multiple-picket-drive pulse designs replace the gradual intensity rise of
the continuous pulse with two or three narrow pickets (each picket is
approximately 100 ps long). These picket designs facilitate shock tuning
using an experimental cone-in-shell platform\footnote{ T. R. Boehly \textit{et al.}, Phys.
Plasmas \textbf{16}, 056302 (2008).} developed for the National Ignition
Campaign. The coalescing shocks are measured with VISAR. The required
shock-timing accuracy is achieved by adjusting the energies of the
individual pickets. The shock-tuned, multiple-picket-drive pulses have been
used to drive cryogenic DT targets to implosion velocities ($>$3 $\times $
10$^{7}$ cm/s) that exceed those reached using continuous-pulse
designs.\footnote{ T. C. Sangster \textit{et al.}, Phys. Rev. Lett. \textbf{100}, 185006
(2008).} This talk will present new multiple-picket shock-timing results and
target performance data (yield, areal density, and ion temperature) from
shock-tuned implosions on OMEGA. The areal density is inferred from the
spectra of knock-on deuterons and the primary neutron down-scattered
fraction using a magnetic recoil spectrometer (primary DT neutrons that
scatter in the dense fuel end up with energies well below 14 MeV; the ratio
of this yield to the primary yield is proportional to the fuel areal
density). Properly tuned implosions produce nearly 1-D areal densities. This
work was supported by the U.S. Department of Energy Office of Inertial
Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.DPP.NI2.2