Cryogneic-Target Performance and Implosion Physics Studies on OMEGA

Journal Article · Fri Mar 06 04:00:00 EST 2009 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3078102· OSTI ID:948811

Smalyuk, V A ^[1]; Betti, R; Boehly, T R; Craxton, R S; Delettrez, J A; Edgell, D H; Glebov, V Yu; Goncharov, V N; Harding, D R; Hu, S X; Knauer, J P; Marshall, F J; McCrory, R L; McKenty, P W; Meyerhofer, D D; Radha, R B; Regan, S P; Sangster, T C; Seka, W; Short, R W ; Shvarts, D; Skupsky, S; Soures, J M; Stoeckl, C; Yaakobi, B; Frenje, J A; Li, C K; Petrasso, R D; Seguin, F H

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1. Laboratory for Laser Energetics, University of Rochester, Rochester, NY

Recent progress in direct-drive cryogenic implosions on the OMEGA Laser Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is reviewed. Ignition-relevant areal densities of ~200 mg/cm^2 in cryogenic D2 implosions with peak laser-drive intensities of ~5 x 10^14 W/cm^2 were previously reported [T. C. Sangster et al., Phys. Rev. Lett. 100, 185006 (2008)]. The laser intensity is increased to ~10^15 W/cm^2 to demonstrate ignition-relevant implosion velocities of 3–4 x 10^7 cm/ s, providing an understanding of the relevant target physics. Planar-target acceleration experiments show the importance of the nonlocal electron-thermal-transport effects for modeling the laser drive. Nonlocal and hot-electron preheat is observed to stabilize the Rayleigh–Taylor growth at a peak drive intensity of ~10^15 W/cm^2. The shell preheat caused by hot electrons generated by two-plasmon-decay instability was reduced by using Si-doped ablators. The measured compressibility of planar plastic targets driven with high-compression shaped pulses agrees well with one-dimensional simulations at these intensities. Shock mistiming has contributed to compression degradation of recent cryogenic implosions driven with continuous pulses. Multiple-picket (shock-wave) target designs make it possible for a more robust tuning of the shock-wave arrival times. Cryogenic implosions driven with double-picket pulses demonstrate somewhat improved compression performance at a peak drive intensity of ~10^15 W/cm^2.

• Research Organization: Laboratory for Laser Energetics, University of Rochester
• Sponsoring Organization: USDOE
• DOE Contract Number: FC52-08NA28302
• OSTI ID: 948811
• Report Number(s): DOE/NA/28302-874; 2008-118; 1852
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 16; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COMPRESSIBILITY
CRYOGENICS
DEUTERIUM
ELECTRONS
IGNITION
IMPLOSIONS
LASERS
OMEGA FACILITY
PERFORMANCE