52nd Annual Meeting of the APS Division of Plasma Physics
Volume 55, Number 15
Monday–Friday, November 8–12, 2010;
Chicago, Illinois
Session QI3: Direct-Drive ICF; X-Ray Diagnostics
3:00 PM–5:00 PM,
Wednesday, November 10, 2010
Room: Grand Ballroom EF
Chair: Christina Back, General Atomics
Abstract ID: BAPS.2010.DPP.QI3.1
Abstract: QI3.00001 : Low-Adiabat, High-Compression Cryogenic Deuterium--Tritium Implosions on OMEGA
3:00 PM–3:30 PM
Preview Abstract
Abstract
Author:
V.N. Goncharov
(Laboratory for Laser Energetics, U. of Rochester)
The performance of cryogenic deuterium--tritium (DT) spherical
implosions using triple-picket designs is reported. These designs
facilitate control of shock heating in low-adiabat inertial
confinement fusion targets. The perturbation growth in
triple-picket designs is controlled by the adiabat shaping
imposed by a series of decaying shocks launched by individual
pickets. Taking advantage of enhanced ablative stabilization of
Rayleigh--Taylor instability makes it possible to simplify target
design by replacing wetted foam in the pusher material with solid
plastic (CH). As reported previously,\footnote{V.N. Goncharov
\textit{et al., }Phys. Rev. Lett. \textbf{104},
165001 (2010).} areal density up to 300 mg/cm$^{2}$, the highest
ever measured in cryogenic-DT implosions, have been measured
using these designs with the implosion velocity $\sim $3 $\times
$ 10$^{7}$ cm/s. This talk will summarize the results on
improving target performance and the progress in theoretical
understanding of cryogenic implosions on OMEGA.
To identify the main limiting sources in target performance and
to improve target yield and ion temperature at the peak
compression, extensive 2-D simulations using the hydrocode
\textit{DRACO} have been performed. Using these simulations,
target sensitivities to different levels of laser-nonuniformity
smoothing, ice roughness, laser-power imbalance, and target
offset were identified. To minimize both the effective beam
mispointing and pulse-shape distortion induced by a 1-Thz,
1-color-cycle SSD system, 0.3-Thz, 3-color-cycle SSD smoothing
was implemented on the OMEGA Laser System. In addition, to
improve target quality, isolated defects in the ice at the
point of contact of the stalk mount with target surface were
mitigated by applying IR heating (ice shimming). This work was
supported by the U.S. Department of Energy (DOE) 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.2010.DPP.QI3.1