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1-D MHD Simulations of an Argon Z-pinch Implosion with Time-dependent Non-LTE Population Kinetics

Ouart, N.D.; Dasgupta, A.D.; Giuliani, J.G.; Jones, Brent M.; Ampleford, David A.; Harvey-Thompson, Adam J.; Jennings, Christopher A.; Maron, Y.M.; Clark, R.W.C.

Abstract not provided.

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TYPE Conference Poster YEAR 2018

OSTI

Development of a slit neutron imager for inertial confinement fusion experiments at the Sandia Z machine

Ampleford, David A.; Alberto, Perry J.; Ball, Christopher R.; Chandler, Gordon A.; Fisher, John A.; Hahn, Kelly D.; Jennings, Christopher A.; Jones, Brent M.; Torres, Jose A.; Vaughan, Jeremy V.; Fittinghoff, D.F.; May, M.J.M.; Gatu-Johnson, M.G.; Lahmann, B.L.

Abstract not provided.

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TYPE Conference Poster YEAR 2018

OSTI

Minimizing scatter-losses during pre-heat for magneto-inertial fusion targets

Physics of Plasmas

Geissel, Matthias G.; Harvey-Thompson, Adam J.; Awe, Thomas J.; Bliss, David E.; Glinsky, Michael E.; Gomez, Matthew R.; Harding, Eric H.; Hansen, Stephanie B.; Jennings, Christopher A.; Kimmel, Mark W.; Knapp, Patrick K.; Lewis, Sean M.; Peterson, Kyle J.; Schollmeier, Marius; Schwarz, Jens S.; Shores, Jonathon S.; Slutz, Stephen A.; Sinars, Daniel S.; Smith, Ian C.; Speas, C.S.; Vesey, Roger A.; Weis, Matthew R.; Porter, John L.

The size, temporal and spatial shape, and energy content of a laser pulse for the pre-heat phase of magneto-inertial fusion affect the ability to penetrate the window of the laser-entrance-hole and to heat the fuel behind it. High laser intensities and dense targets are subject to laser-plasma-instabilities (LPI), which can lead to an effective loss of pre-heat energy or to pronounced heating of areas that should stay unexposed. While this problem has been the subject of many studies over the last decades, the investigated parameters were typically geared towards traditional laser driven Inertial Confinement Fusion (ICF) with densities either at 10% and above or at 1% and below the laser's critical density, electron temperatures of 3-5 keV, and laser powers near (or in excess of) 1 × 1015 W/cm2. In contrast, Magnetized Liner Inertial Fusion (MagLIF) [Slutz et al., Phys. Plasmas 17, 056303 (2010) and Slutz and Vesey, Phys. Rev. Lett. 108, 025003 (2012)] currently operates at 5% of the laser's critical density using much thicker windows (1.5-3.5 μm) than the sub-micron thick windows of traditional ICF hohlraum targets. This article describes the Pecos target area at Sandia National Laboratories using the Z-Beamlet Laser Facility [Rambo et al., Appl. Opt. 44(12), 2421 (2005)] as a platform to study laser induced pre-heat for magneto-inertial fusion targets, and the related progress for Sandia's MagLIF program. Forward and backward scattered light were measured and minimized at larger spatial scales with lower densities, temperatures, and powers compared to LPI studies available in literature.

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TYPE Journal Article YEAR 2018

Scopus OSTI DOI

Data-driven compressed sensing tomography

IS and T International Symposium on Electronic Imaging Science and Technology

Kassubeck, Marc; Wenger, Stephan; Jennings, Christopher A.; Gomez, Matthew R.; Harding, Eric; Schwarz, Jens S.; Magnor, Marcus

This paper presents a new method for tomographic reconstruction of volumes from sparse observational data. Application scenarios can be found in astrophysics, plasma physics, or whenever the amount of obtainable measurement is limited. In the extreme only a single view of the phenomenon may be available. Our method uses input image data together with complex, user-definable assumptions about 3D density distributions. The parameter values of the user-defined model are fitted to the input image. This allows for incorporating complex, data-driven assumptions, such as helical symmetry, into the reconstruction process. We present two different sparsity-based reconstruction approaches. For the first method, novel virtual views are generated prior to tomography reconstruction. In the second method, voxel groups of similar target densities are defined and used for group sparsity reconstruction. We evaluate our method on real data of a high-energy plasma experiment and show that the reconstruction is consistent with the available measurement and 3D density assumptions. An additional experiment on simulated data demonstrates possible gains when adding an additional view to the presented reconstruction methods.

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TYPE Conference Poster YEAR 2018

Scopus OSTI DOI