Bulletin of the American Physical Society
63rd Annual Meeting of the APS Division of Plasma Physics
Volume 66, Number 13
Monday–Friday, November 8–12, 2021; Pittsburgh, PA
Session BO03: HED: Hydrodynamics and Magnetohydrodynamics IOn Demand
|
Hide Abstracts |
Chair: Joshua Sauppe, Los Alamos National Laboratory Room: Rooms 302-303 |
Monday, November 8, 2021 9:30AM - 9:42AM |
BO03.00001: Quantifying the Effect of Heterogeneous Mix on Thermonuclear Burn in the Marble Campaign Thomas J Murphy, Brian J Albright, Melissa R Douglas, James H Cooley, Thomas Day, Carlos A Di Stefano, Rob A Gore, Mark A Gunderson, Jeff Haack, Brian M Haines, Chris E Hamilton, Yongho Kim, Matthew N Lee, Tana Morrow, John A Oertel, Rick E Olson, Randall B Randolph, Joseph M Smidt, Lin Yin, Rahul C Shah The recently concluded Marble campaign [T J Murphy et al, J Phys:Conf Series 717, 012072 (2016)] on the National Ignition Facility quantified the effect of heterogeneous mix on thermonuclear burn for comparison to a probability distribution function (PDF) burn model. [J R Fincke, unpublished; J R Ristorcelli, Phys Fluids 29, 020705 (2017).] MARBLE utilized plastic capsules filled with deuterated plastic foam and tritium-containing gas. The final experiments, which utilized an argon-tritium gas mixture, show the expected decrease in DT/DD yield ratio with non-uniform initial foam morphology, while previous experiments with a hydrogen-tritium gas mixture did not. [T J Murphy et al, High Energy. Dens. Phys. 38,100929 (2021).] |
Monday, November 8, 2021 9:42AM - 9:54AM |
BO03.00002: Divergent Shock-Bubble Interactions in High Energy Density Plasmas Pawel M Kozlowski, Yongho Kim, Brian M Haines, Joseph M Smidt, Tana Morrow, Shaun G Newman, Thomas J Murphy, Melissa R Douglas, Brian J Albright Shock-bubble interaction (SBI) experiments are a building block for understanding supersonic flows in inhomogeneous media. Although SBI have been studied extensively in low energy systems, data in the high energy density (HED) regime have focused primarily on convergent SBI. We present the Marble VC platform, fielded on Omega-60, for studying divergent SBI in HED plasma flows. Using computer vision techniques we identify features characteristic of divergent SBI, and directly compare these features to highly constrained radiation-hydrodynamic simulations in xRAGE. Using the initial target and laser conditions, with no additional energy tuning, we find good agreement with features identified in experiment. This work connects the classical hydrodynamic theory of SBI, based on acoustic impedance and baroclinicity, to the HED plasma regime via identification of features characteristic of divergent SBI, and thereby provides a basis for understanding generalized plasma flows through inhomgeneous media using the classical theory. This has implications for plasma flows through porous media, as observed in NIF Marble separated reactants experiments. LA-UR-21-26677 |
Monday, November 8, 2021 9:54AM - 10:06AM |
BO03.00003: Modeling Radiative Shock Propagation through Heterogenous Media in High-Energy-Density Regime Lauren Green, Yongho Kim, Brian M Haines, Pawel M Kozlowski, Thomas J Murphy The MARBLE campaign at Los Alamos National Laboratory (LANL) is a series of inertial confinement fusion (ICF) experiments employing plastic foams with engineered macro-pores designed to investigate heterogeneous material mixing during laser driven shock implosions. Accurately modeling the dynamics of these foams is challenging for radiation-hydrodynamics codes due to the complex geometry that stresses multi-material modeling of equation of state (EOS) opacity, thermal conduction, and thermonuclear burn. We employed xRAGE, a LANL Eulerian radiation-hydrodynamics code, to perform the simulations and study the material effects and shock propagation in comparison with the results of companion MARBLE Void Collapse experiments performed on the OMEGA laser at the Laboratory for Laser Energetics (LLE). Experimental shock propagation data helped guide three numerical simulation approaches using xRAGE: (1) a 2D homogenous foam approximation (2) a 2D toroidal-pore approximation (3) a full 3D calculation simulating spherical macro-pores. These simulation results agree with each other within 5% uncertainty demonstrating that the mixed EOS models are sufficient to model the shock speeds and the 2D approximations do not degrade accuracy in estimating shock propagation through heterogeneous macro-pore foams. |
Monday, November 8, 2021 10:06AM - 10:18AM |
BO03.00004: Effect of Fill Pressure and Species on Low-Convergence Implosions David T Bishel, Philip M Nilson, David A Chin, John J Ruby, Suxing X Hu, J. Ryan R Rygg, Gilbert Collins, Edward V Marley Implosions present a fruitful platform for conducting atomic physics studies of mid-Z materials under compression as fusion-related design constraints can be relaxed. We will present on the use of fill pressure and dopant species to modify the thermodynamic trajectory of an imploded plastic shell with an embedded mid-Z tracer layer. To ensure that the tracer layer remains localized within the shell, a low-convergence implosion design is used, producing greater hydrodynamic stability than higher-convergence implosions traditionally used in inertial confinement fusion. Targets consist of 880-μm-outer-diameter, 30-μm-thick spherical CH capsules filled with D2 at various pressures (2 atm or 20 atm) and with various dopant species (1.27 at % Ar or Kr); a 0.2-μm bilayer of Cr and Ni is recessed 8 μm from the inner surface. The targets were driven with 27 kJ of laser energy over 1 ns. The effect of the gas fill on radiative power loss of the core, stagnated core radius, and thermodynamic states accessed by the shell is inferred from forward-fitting synthetic data from an implosion model to observed imaging and spectral data. |
Monday, November 8, 2021 10:18AM - 10:30AM |
BO03.00005: Mitigation of the Kelvin-Helmholtz Instability in HED conditions by a strong external magnetic field Alexis Casner, Victorien Bouffetier, Luke Ceurvorst, Gabriel Perez Callejo, Thibault GOUDAL, Hong W Sio, Jonathan L Peebles, Petros Tzeferacos, Vladimir Smalyuk, Omar A Hurricane The Kelvin-Helmholtz Instability (KHI) is ubiquitous in the Universe, governing coronal mass ejections as well as planetary magnetospheres. In HED and ICF, KHI is encountered in hohlraum wall plasmas and during the late phase of evolution of Rayleigh-Taylor Instability spikes. We present a novel platform developed on OMEGA for exploring the magnetized Kelvin-Helmholtz Instability in HED conditions. While the stabilizing effect of a tangential magnetic field along the velocity shear is well known since Chandrasekhar’s book, few experimental validations exist in the literature. Based on recent numerical studies [1], we show theoretically how a strong external magnetic field (40 T) could mitigate the instability in blast wave flow conditions. Taking advantage of dual MIFEDS development on OMEGA recent results of the magKHI platform commissioning will be presented. Future plans for leveraging this platform to investigate KHI in supersonic sustained flows conditions are discussed. This project have deep implications across a wide range of HED physics research, including laboratory astrophysics, mix studies, and magnetized ICF designs. |
Monday, November 8, 2021 10:30AM - 10:42AM |
BO03.00006: Vorticity induced mixing in the Rayleigh-Taylor Instability Adrianna Angulo, Sabrina R Nagel, Gareth N Hall, Chris Weber, Harry F Robey, Alexandre Do, Louisa Pickworth, Carolyn C Kuranz In high-energy-density physics (HEDP), mixing due to the Rayleigh-Taylor instability (RTI) is prevalent in a wide range of flows relevant to inertial-confinement fusion (ICF) and astrophysics. As the mixing increases, nonlinearities and secondary instabilities develop. Eventually, these instabilities dominate in the mixing process and contribute to cooling the hot fuel in ICF. HED experiments conducted on the National Ignition Facility (NIF) have primarily focused on measuring the layer width of mixed materials caused by RTI. With diagnostic improvements, recent experimental radiographs have imaged secondary instability growth along the RT spike tip. In contrast, simulations that assume an ideal interface as an initial condition fail to reproduce this growth of secondary structures. Here we discuss what causes these secondary instabilities to appear, as well as their contribution to the mixing process. We then use simulations and synthetic radiographs to highlight the contribution of a non-ideal initial interface to vorticity-induced mixing on the RT rollup. Continued improvements in resolution can shed further light on the involvement of the RTI and secondary instabilities in mixing. |
Monday, November 8, 2021 10:42AM - 10:54AM |
BO03.00007: Effects of ablation and mode coupling on the deeply nonlinear stages of the Rayleigh-Taylor instability Luke Ceurvorst, Alexis Casner, Vladimir Smalyuk, Laurent Masse, David A Martinez, Shahab Khan, Nobuhiko Izumi, Igor Igumenshchev, Valeri N Goncharov, Gabriel Perez Callejo, Thibault GOUDAL The Rayleigh-Taylor Instability (RTI) can be found at the interface of a light fluid pushing against a heavy fluid, causing any surface perturbations to grow exponentially in time. It occurs at all scales of the universe and is one of the canonical hydrodynamic instabilities leading to turbulence. Despite its prevalence, a great deal of uncertainty still surrounds its nonlinear stage of evolution. A recent experiment at the National Ignition Facility (NIF) explored the ablative form of this phenomenon and demonstrated that its nonlinear development is strongly influenced by the interface’s initial conditions [1]. However, while this behavior is well explained by recent theoretical work at the early stages of nonlinearity [2], its latest-time behavior deviates significantly from expectations. To address this, a new experiment has been designed at the NIF both to examine the cause of this disagreement and to explore the role of ablation in the system’s overall development. The first day of shots is scheduled for October 2021 and will provide valuable insights into the dynamic interplay of multimode bubble evolution. |
Monday, November 8, 2021 10:54AM - 11:06AM |
BO03.00008: High-Resolution X-Ray Imaging of Blast-Wave–Driven Instabilities Philip M Nilson, Frederic J Marshall, Timothy J Collins, Reuben Epstein, David T Bishel, David A Chin, John J Ruby, Joshua Kendrick, Dale Guy, Steven T Ivancic, Christian Stoeckl, Valeri N Goncharov, Dustin H Froula Two-dimensional x-ray radiography was used to measure hydrodynamic-instability growth at a modulated, blast-wave–driven interface between a laser-driven plastic pusher and a low-density foam. The ablatively driven system was generated on the OMEGA Laser System with up to few-nanosecond-duration laser pulses at focused intensities above 1014 W/cm2. Radiographs were obtained using a 4.75-keV Ti He-like resonance line area backlighting source coupled to a Fresnel phase zone plate imager and an SI-800 x-ray charge-coupled device. Resolution grid tests confirm the achievement of micron-level static spatial resolution. With few-micron dynamic resolution, the data show clear bubble and spike growth and the effects of vorticity and asymmetric shear on the spike-tip morphology. Of note is the clarity in the imaged material response to the counter-rotating vortex pairs that form at the spike tips during roll-up. The data are compared with synthetic x-ray radiographs generated from numerical simulations using the computer codes DRACO and SPECT3D. |
Monday, November 8, 2021 11:06AM - 11:18AM |
BO03.00009: Interaction between a strong laser-ablation shock and a shock wave from the supersonic-to-subsonic transition of radiation Felicie Albert, Dean R Rusby, Stephen D Murray, Allen Toreja, Shon T Prisbrey We present the results of an experiment carried out at the Omega laser facility to study the interaction between a strong (multi-Mbar) shock driven by direct laser ablation and a weaker shock induced by the supersonic-to-subsonic transition of radiation in silica (SiO2) aerogel. The physics package is comprised of a silica foam cylinder exposed to a ~100 eV radiation drive created by a laser-driven halfraum, which induces a supersonic radiation front propagating axially into the cylinder. A counter-propagating shock is generated using directly laser-driven CH and Al foils which collides with the transitioning super-to-sub sonic shock. X-ray radiography shows the counter-propagation of both shocks and their interaction. This process is observed in several high-energy-density experiments and our campaign demonstrates that it can be accurately simulated with the radiation hydrodynamic code KULL. |
Monday, November 8, 2021 11:18AM - 11:30AM Not Participating |
BO03.00010: Investigation of pulse length’s effect on direct laser ablation and shock generation at Intensity of 1015 Wcm-2 Tanner Cordova A significant threat for exo-atmospheric objects is thermomechanical shock via x-ray irradiation. Utilizing direct laser-driven ablation as a surrogate, simulations and experimental data show a direct relationship between the laser pulse length and ablation plasma properties and shock generation. Experiments were carried out at the OMEGA-EP Laser Facility at the Laboratory for Laser Energetics (LLE) at the University of Rochester where 3-layer targets of Silicon (50mm), Copper (25mm) and Quartz (500mm) were irradiated at a fixed total intensity of 1015 Wcm-2 with varying pulse lengths of 100ps, 500ps, 1ns and 10ns duration. In this study, we experimentally observed that the generated shock velocities increase with the laser pulse length. Further, we observed increases in the ablation plasma scale length, electron temperature and ablation pressure with increasing laser pulse length. A comparison with 2D radiation-hydrodynamic simulations will be presented. |
Monday, November 8, 2021 11:30AM - 11:42AM |
BO03.00011: HED same-sided successive-shock instability experiments at the NIF Elizabeth C Merritt, Carlos A Di Stefano, Forrest W Doss, Kirk A Flippo, Harry F Robey, Alexander Rasmus, Joseph M Levesque, Ryan F Sacks, Derek Schmidt, Marius Millot The presence of multiple shocks interacting with multiple material interfaces is ubiquitous in ICF, but is often poorly validated in these complex systems. The LANL NIF MShock campaign is developing a capability to study RM/RT growth in a multiple layer, multiple-shock regime. We previously demonstrated the novel ability to generate 2 successive shocks from the same direction in a planar target. The physics of successive shocks accesses a much richer space than a single shock or an opposite reshock, not easily accessed in classical shock tubes. Idealized fluid theory [Mikaelian, PRA 1985] predicts 15 different growth cases for a single mode under successive shocks. Mshock single-mode and two-mode experiments demonstrate that perturbations can re-invert, freeze, or continue to grow based the experiment initial conditions, as predicted by theory. We are able to vary both the initial perturbation and the relative strengths and timings of the two shocks to vary the instability growth. Shock strength and timing experiments take advantage of a new simultaneous VISAR and imaging target that allows acquisition of a drive measurement and completed image data set in a single 3 shot, 24 hour sequence. |
Monday, November 8, 2021 11:42AM - 11:54AM |
BO03.00012: Studying successive shock effects on heavy-to-light instabilities Forrest W Doss, E. C Merritt, C. A Di Stefano, H. F Robey, K. A Flippo, R. F Sacks, A. M Rasmus, J. M Levesque The Richtmyer-Meshkov instability of shocked interfaces is believed to be a major contributor to mix in shaped-pulse ICF capsules, where multiple shocks typically pass through the inner interfaces and converge near the center. Sending multiple successive shocks through a heavy-to-light interface can lead to distinct outcomes compared to either a single shock or a shock followed by reshock from the opposite direction. This can theoretically include partial or complete `freeze-out’ of the perturbation after the second shock, reducing total mix width. We review some of the theory of successively shocked heavy-to-light interfaces as previously developed by Mikaelian[1], and results from a recent planar halfraum-drive experiment which has verified some of these ideas. |
Monday, November 8, 2021 11:54AM - 12:06PM |
BO03.00013: Modeling of a hybrid direct/indirect-drive scheme for producing complex hydrodynamic profiles involving copropagating shocks Carlos A Di Stefano, Elizabeth C Merritt, Forrest W Doss, Kirk A Flippo, Alexander Rasmus, Joseph M Levesque, Ryan F Sacks, David D Meyerhofer, Harry F Robey, Brian M Haines, Barbara G DeVolder, Tiffany R Desjardins, Derek Schmidt, Lynn Kot, Theodore S Perry Co-propagating shocks are important in many HED situations, yet are significantly more challenging to produce than counter-propagating shocks and thus remain understudied. Los Alamos has developed an experimental platform, using sequential direct and indirect drive in a single halfraum, to create such co-propagating shocks and study their effects. This talk will discuss aspects of the modeling capability developed to support the experimental platform. Since the hybrid drive scheme requires the second shock to form under dynamically-evolving plasma conditions, there is significant demand on the capacity of simulations for capturing the evolution of the shocks, for example in the physics of the laser interaction with the system and the transport mechanisms from the deposition region to the shock front. We will discuss some of these considerations, as well as our current predictive capability. |
Monday, November 8, 2021 12:06PM - 12:18PM |
BO03.00014: Experiments studying the impact of the initial conditions on multimode HED hydrodynamic instability growth Alexander Rasmus, Carlos A Di Stefano, Forrest W Doss, Kirk A Flippo, Joseph M Levesque, Elizabeth C Merritt Hydrodynamic instabilities are ubiquitous on interfaces that interact with shocks. These instabilities are often seeded by surface roughness that is too computationally expensive to resolve directly. Furthermore, the instability growth is often initially laminar, so that the best way to initialize sub-grid turbulence models isn't readily apparent. Here, we present recent Omega-EP experiments designed to address the impact of initial conditions on mix by resolving multimode Richtmyer-Meshkov with delayed onset Rayleigh-Taylor growth at both linear and deeply non-linear times. Three initial conditions are compared. The wavelengths of the nine modes present and overall perturbation amplitude are kept constant across perturbations, whereas the weighting between long and short modes is varied across perturbations. |
Monday, November 8, 2021 12:18PM - 12:30PM |
BO03.00015: Exploring the Landau-Darrieus instability in High Energy Density conditions: Analytical model and FLASH simulations Thibault GOUDAL, Laurent Masse, Shahab F Khan, David A Martinez, Luke Ceurvorst, Gabriel Perez Callejo, Victorien Bouffetier, Nobuhiko Izumi, Daniel H Kalantar, Marius Millot, Vladimir Smalyuk, Bruce Remington, Arnaud Colaïtis, Alexis Casner Recent experimental work has been presented [Direct Drive Fast Ignition Workshop, T.Goudal] which was designed to observe the Landau-Darrieus Instability (LDI) for the first time in the context of laser-driven ablation fronts1,2,3. The most recent experiments were conducted at the National Ignition Facility (NIF) and build upon previous work conducted at OMEGA EP. In order to design future experiments and build a reliable tool to be compared with experimental results, a coherent analytical model4,5 has been developed to describe the hydrodynamic system within the conduction zone. Under certain assumptions, this model enables the study of the linear stability of the system and highlights the effect of LDI at the ablation front. To avoid stabilizing the LDI, the conduction zone length Dc must be smaller than the studied wavelength. To compare to and benchmark this model, 1D/2D FLASH simulations have been performed to study the instability’s behavior at the ablation front. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700