OMEGA polar-drive target designs

Journal Article · Tue Aug 07 04:00:00 EDT 2012 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4742320· OSTI ID:1052152

Radha, P. B. ^[1]; Marozas, J. A. ^[2]; Marshall, F. J. ^[2]; Shvydky, A. ^[2]; Collins, T. B. ^[2]; Goncharov, V. N. ^[2]; McCrory, R. L. ^[3]; McKenty, P. W. ^[2]; Meyerhofer, D. D. ^[3]; Sangster, T. C. ^[2]; Skupsky, S. ^[2]

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1. Laboratory for Laser Energetics, University of Rochester 1 , 250 E. River Road, Rochester, New York 14623, USA; Laboratory for Laser Energetics, University of Rochester, Rochester, NY
2. Laboratory for Laser Energetics, University of Rochester 1 , 250 E. River Road, Rochester, New York 14623, USA
3. Laboratory for Laser Energetics, University of Rochester 1 , 250 E. River Road, Rochester, New York 14623, USA; Department of Mechanical Engineering and Department of Physics, University of Rochester 2 , 250 E. River Road, Rochester, New York 14623, USA

Low-adiabat polar-drive (PD) [Skupsky et al., Phys. Plasmas 11, 2763 (2004)] implosion designs for the OMEGA [Boehly et al., Opt. Commun. 133, 495 (1997)] laser are described. These designs for cryogenic deuterium–tritium and warm plastic shells use a temporal laser pulse shape with three pickets followed by a main pulse [Goncharov et al., Phys. Rev. Lett. 104, 165001 (2010)]. The designs are at two different on-target laser intensities, with different in-flight aspect ratios (IFARs). These designs permit studies of implosion energetics and target performance closer to ignition-relevant intensities (~7 x 10¹⁴ W/cm² at the quarter-critical surface, where nonlocal heat conduction and laser–plasma interactions can play an important role) but at lower values of IFAR ~ 22 or at lower intensity (~3 x 10¹⁴ W/cm²) but at a higher IFAR (IFAR ~32, where shell instability can play an important role). PD geometry requires repointing of laser beams to improve shell symmetry. The higher-intensity designs optimize target performance by repointing beams to a lesser extent, compensating for the reduced equatorial drive by increasing the energies of the repointed beams. They also use custom beam profiles that improve equatorial illumination at the expense of irradiation at higher latitudes. These latter designs will be studied when new phase plates for the OMEGA Laser System, corresponding to the custom beam profiles, are obtained.

• Research Organization: Univ. of Rochester, NY (United States). Lab. for Laser Energetics
• Sponsoring Organization: USDOE
• DOE Contract Number: FC52-08NA28302
• OSTI ID: 1052152
• Report Number(s): DOE/NA/28302-1078; 2012-26; 2054
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 8 Vol. 19; ISSN 1070-664X
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English