Viscosity Measurements in Shock-compressed Epoxy

ORAL

Abstract

Viscosity gives insight into the momentum transport in a system and plays a crucial role in mixing and growth of hydrodynamic instabilities. Viscosity measurements in High Energy Density(HED) states are particularly important to accurately develop hydrodynamic models and to bridge the gap between simulations and experimental results of complex systems such as Inertial Confinement Fusion (ICF). Inclusion of viscous dissipation in the modelling of ICF implosions has led to a better understanding of hot spot turbulence (C. R. Weber, 2014), (B. M. Haines, 2014), demonstrating the importance of further studies in the direction.

We measured viscosity at high pressures (peak⁓248 GPa), in CH under laser-driven shock compression.We measured viscosity in dynamically compressed Stycast 1266 (CH, 1.1

g/cc) by tracing the acceleration of particles embedded in the target. The OMEGA-60 laser facilitywas used to drive a shock (peak⁓248 GPa) through the CH target, which was embedded with stainless steel (7.8 g/cc) and titanium (4.56 g/cc) microspheres that were accelerated by the flow behind theshock. The particle positions were recorded with time-resolved X-ray radiography. The velocities of the particles and Stycast were used to determine the viscous and inviscid force contributions acting on the particles using a shock-particle forcing model. From the forces, we calculated the dynamic viscosity of Epoxy to be O(1) Pa-sec. We have perfomed X-ray diffraction experiments to determine the physical state of shocked Epoxy, to understand its effect on the magnitude of viscosity. A Quasi-steady analysis of the problem is also being performed to study the viscous effects on deformed particle and compare it with the viscosity calculated from the force model.

*The experiment was conducted at the Omega Laser Facility at the University of Rochester's Laboratory for Laser Energetics with the beam time through the Laboratory Basic Sciences (LBS) program. This work was supported by US DOE and NNSA under the joint HEDLP program under grant DE-SC0019329 and DE-NA0004134. Partial support from grants NSF PHY-2020249, DE-SC0020229 and DE-NA0003914 is also acknowledged.

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Publication: B. M. Haines, E. L. (2014). The effects of plasma diffusion and viscosity on turbulent
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hydrocarbons at 1--10 Mbar using laser-driven shock waves. Physics
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C. R. Weber, D. S. (2014). Inhibition of turbulence in inertial-confinement-fusion hot
spots by viscous dissipation. Physical review. E, Statistical, nonlinear,
and soft matter physics, 053106.
Parmar, M. a. (2011). Generalized Basset-Boussinesq-Oseen equation for
unsteady forces on a sphere in a compressible flow. Physical review
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Presenters

  • Afreen Syeda

    • University of Rochester

Authors

  • Afreen Syeda

    • University of Rochester

  • Jessica K Shang

    • University of Rochester

  • Hussein Aluie

    • University of Rochester

  • Nitish Acharya

    • University of Rochester

  • Kelin Kurzer-Ogul

    • Dept. of Mechanical Eng, University of Rochester

  • Hadley Michelle Pantell

    • University of Rochester

  • D. A. Alexander Chin

    • University of Rochester
    • Laboratory for Laser Energetics

  • Danae N Polsin

    • Laboratory for Laser Energetics

  • James R Rygg

    • Laboratory for Laser Energetics, University of Rochester
    • University of Rochester

  • Riccardo Betti

    • Laboratory for Laser Energetics, University of Rochester
    • Laboratory for Laser Energy, Rochester, NY, USA.

  • Gilbert W Collins

    • Laboratory for Laser Energetics
    • University of Rochester
    • Laboratory for Laser Energetics, University of Rochester

  • Arianna E Gleason

    • SLAC - Natl Accelerator Lab
    • SLAC National Accelerator Laboratory

  • John J Ruby

    • Lab for Laser Energetics

  • Anjeli Estrada Alvarez

    • University of Rochester