Publications

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Pulsed-power driven inertial confinement fusion development at Sandia National Laboratories

Proposed for publication in 5th Special Issue of the IEEE Transactions on Plasma Science Z-Pinch Plasmas.

Cuneo, M.E.; Mazarakis, Michael G.; Lamppa, Derek C.; Kaye, Ronald J.; Nakhleh, Charles N.; Bailey, James E.; Hansen, Stephanie B.; McBride, Ryan D.; Herrmann, Mark H.; Lopez, A.; Peterson, Kyle J.; Ampleford, David A.; Jones, Michael J.; Savage, Mark E.; Jennings, Christopher A.; Martin, Matthew; Slutz, Stephen A.; Lemke, Raymond W.; Christenson, Peggy J.; Sweeney, Mary A.; Jones, Brent M.; Yu, Edmund Y.; McPherson, Leroy A.; Harding, Eric H.; Knapp, Patrick K.; Gomez, Matthew R.; Awe, Thomas J.; Stygar, William A.; Leeper, Ramon J.; Ruiz, Carlos L.; Chandler, Gordon A.; Mckenney, John M.; Owen, Albert C.; McKee, George R.; Matzen, M.K.; Leifeste, Gordon T.; Atherton, B.W.; Vesey, Roger A.; Smith, Ian C.; Geissel, Matthias G.; Rambo, Patrick K.; Sinars, Daniel S.; Sefkow, Adam B.; Rovang, Dean C.; Rochau, G.A.

Abstract not provided.

Penetrating radiography of imploding and stagnating beryllium liners on the Z accelerator

Physical Review Letters

McBride, Ryan D.; Peterson, Kyle J.; Sefkow, Adam B.; Nakhleh, Charles N.; Laspe, Amy R.; Lopez, Mike R.; Smith, Ian C.; Atherton, B.W.; Savage, Mark E.; Stygar, William A.; Slutz, Stephen A.; Rogers, Thomas J.; Jennings, Christopher A.; Sinars, Daniel S.; Cuneo, M.E.; Herrmann, Mark H.; Lemke, Raymond W.; Martin, Matthew; Vesey, Roger A.

Abstract not provided.

Measurements of Magneto-Rayleigh-Taylor instability growth in initially solid liners on the Z facility

Sinars, Daniel S.; Edens, Aaron E.; Lopez, Mike R.; Smith, Ian C.; Slutz, Stephen A.; Shores, Jonathon S.; Bennett, Guy R.; Atherton, B.W.; Savage, Mark E.; Stygar, William A.; Leifeste, Gordon T.; Herrmann, Mark H.; Cuneo, M.E.; Peterson, Kyle J.; McBride, Ryan D.; Jennings, Christopher A.; Vesey, Roger A.; Nakhleh, Charles N.

Abstract not provided.

Measurements of magneto-Rayleigh-Taylor instability growth during the implosion of initially solid metal liners

Physics of Plasmas

Sinars, Daniel S.; Edens, Aaron E.; Lopez, Mike R.; Smith, Ian C.; Shores, Jonathon S.; Slutz, Stephen A.; Bennett, Guy R.; Atherton, B.W.; Savage, Mark E.; Stygar, William A.; Leifeste, Gordon T.; Herrmann, Mark H.; McBride, Ryan D.; Cuneo, M.E.; Jennings, Christopher A.; Peterson, Kyle J.; Vesey, Roger A.; Nakhleh, Charles N.

Abstract not provided.

Measurements of Magneto-Rayleigh-Taylor instability growth in solid liners on the 20 MA Z facility

Sinars, Daniel S.; Edens, Aaron E.; Lopez, Mike R.; Smith, Ian C.; Shores, Jonathon S.; Bennett, Guy R.; Atherton, B.W.; Savage, Mark E.; Stygar, William A.; Leifeste, Gordon T.; Slutz, Stephen A.; Herrmann, Mark H.; Cuneo, M.E.; Peterson, Kyle J.; McBride, Ryan D.; Vesey, Roger A.; Nakhleh, Charles N.; Tomlinson, Kurt T.

The magneto-Rayleigh-Taylor (MRT) instability is the most important instability for determining whether a cylindrical liner can be compressed to its axis in a relatively intact form, a requirement for achieving the high pressures needed for inertial confinement fusion (ICF) and other high energy-density physics applications. While there are many published RT studies, there are a handful of well-characterized MRT experiments at time scales >1 {micro}s and none for 100 ns z-pinch implosions. Experiments used solid Al liners with outer radii of 3.16 mm and thicknesses of 292 {micro}m, dimensions similar to magnetically-driven ICF target designs [1]. In most tests the MRT instability was seeded with sinusoidal perturbations ({lambda} = 200, 400 {micro}m, peak-to-valley amplitudes of 10, 20 {micro}m, respectively), wavelengths similar to those predicted to dominate near stagnation. Radiographs show the evolution of the MRT instability and the effects of current-induced ablation of mass from the liner surface. Additional Al liner tests used 25-200 {micro}m wavelengths and flat surfaces. Codes being used to design magnetized liner ICF loads [1] match the features seen except at the smallest scales (<50 {micro}m). Recent experiments used Be liners to enable penetrating radiography using the same 6.151 keV diagnostics and provide an in-flight measurement of the liner density profile.

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Pulsed power driven Magneto-Rayleigh-Taylor experiments

Slutz, Stephen A.; Herrmann, Mark H.; Vesey, Roger A.; Sefkow, Adam B.; Sinars, Daniel S.; Rovang, Dean C.; Peterson, Kyle J.; Cuneo, M.E.

Numerical simulations indicate that significant fusion yields (>100 kJ) may be obtained by pulsed-power-driven implosions of cylindrical metal liners onto magnetized and preheated deuterium-tritium fuel. The primary physics risk to this approach is the Magneto-Rayleigh-Taylor (MRT) instability, which operates during both the acceleration and deceleration phase of the liner implosion. We have designed and performed some experiments to study the MRT during the acceleration phase, where the light fluid is purely magnetic. Results from our first series of experiments and plans for future experiments will be presented. According to simulations, an initial axial magnetic field of 10 T is compressed to >100 MG within the liner during the implosion. The magnetic pressure becomes comparable to the plasma pressure during deceleration, which could significantly affect the growth of the MRT instability at the fuel/liner interface. The MRT instability is also important in some astronomical objects such as the Crab Nebula (NGC1962). In particular, the morphological structure of the observed filaments may be determined by the ratio of the magnetic to material pressure and alignment of the magnetic field with the direction of acceleration [Hester, ApJ, 456, 225 1996]. Potential experiments to study this MRT behavior using the Z facility will be presented.

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Assessment of radiography for diagnosing short wavelength instability growth and mix in NIF ignition capsules

Peterson, Kyle J.; Vesey, Roger A.; Herrmann, Mark H.

Understanding and controlling hydrodynamic instabilities is critical to achieving ignition at National Ignition Facility (NIF). High resolution x-ray radiography of a NIF capsule may be able to measure key aspects of short wavelength instability growth including time dependent areal density variations, the dominant wavelength of growth, amount of growth from isolated capsule defects on the ablator and ice surfaces, and growth of perturbations as a result of the fill tube or dust contaminants. Radiography of the capsule limb may also place constraints on the width of the ice/ablator mix layer. Measurement of these various observables are important to determine what effect target design changes has on instability growth and to validate code predictions. We present an analysis of 2D and 3D HYDRA simulations and demonstrate how radiography can be used to diagnose signatures of mix in NIC capsules.

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Fill-Tube-Induced Mass Perturbations on X-Ray-Driven, Ignition-Scale, Inertial-Confinement-Fusion Capsule Shells and the Implications for Ignition Experiments

Physical Review Letters

Bennett, Guy R.; Keller, Keith L.; Mulville, Thomas D.; Peterson, Kyle J.; Sinars, Daniel S.; Smith, Ian C.; Vesey, Roger A.; Herrmann, Mark H.; Christenson, Peggy J.; Cuneo, M.E.

We present on the first inertial-confinement-fusion ignition facility, the target capsule will be DT filled through a long, narrow tube inserted into the shell. μg-scale shell perturbations Δm' arising from multiple, 10–50 μm-diameter, hollow SiO2 tubes on x-ray-driven, ignition-scale, 1-mg capsules have been measured on a subignition device. Finally, simulations compare well with observation, whence it is corroborated that Δm' arises from early x-ray shadowing by the tube rather than tube mass coupling to the shell, and inferred that 10–20 μm tubes will negligibly affect fusion yield on a full-ignition facility.

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Results 151–175 of 185
Results 151–175 of 185