Rayleigh-Taylor-instability evolution in colliding-plasma-jet experiments with magnetic and viscous stabilization

Technical Report · Thu Jan 15 00:00:00 EST 2015

DOI:https://doi.org/10.2172/1167484· OSTI ID:1167484

Adams, Colin Stuart ^[1]

---

1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States); Univ. of Washington, Seattle, WA (United States)

The Rayleigh-Taylor instability causes mixing in plasmas throughout the universe, from micron-scale plasmas in inertial confinement fusion implosions to parsec-scale supernova remnants. The evolution of this interchange instability in a plasma is influenced by the presence of viscosity and magnetic fields, both of which have the potential to stabilize short-wavelength modes. Very few experimental observations of Rayleigh-Taylor growth in plasmas with stabilizing mechanisms are reported in the literature, and those that are reported are in sub-millimeter scale plasmas that are difficult to diagnose. Experimental observations in well-characterized plasmas are important for validation of computational models used to make design predictions for inertial confinement fusion efforts. This dissertation presents observations of instability growth during the interaction between a high Mach-number, initially un-magnetized plasma jet and a stagnated, magnetized plasma. A multi-frame fast camera captures Rayleigh-Taylor-instability growth while interferometry, spectroscopy, photodiode, and magnetic probe diagnostics are employed to estimate plasma parameters in the vicinity of the collision. As the instability grows, an evolution to longer mode wavelength is observed. Comparisons of experimental data with idealized magnetohydrodynamic simulations including a physical viscosity model suggest that the observed instability evolution is consistent with both magnetic and viscous stabilization. These data provide the opportunity to benchmark computational models used in astrophysics and fusion research.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1167484
• Report Number(s): LA-UR-15-20272; TRN: US1500372
• Resource Relation: Related Information: Dissertation
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
79 ASTRONOMY AND ASTROPHYSICS
FLUTE INSTABILITY
RAYLEIGH-TAYLOR INSTABILITY
PLASMA JETS
INERTIAL CONFINEMENT
ICF DEVICES
TIME DEPENDENCE
EXPERIMENTAL DATA
INSTABILITY GROWTH RATES
STABILIZATION
COMPARATIVE EVALUATIONS
MAGNETIC PROBES
SUPERNOVA REMNANTS
VALIDATION
VISCOSITY
MAGNETIC FIELDS
BENCHMARKS
DESIGN
PLASMA DIAGNOSTICS
IMPLOSIONS
COLLISIONS
INTERFEROMETRY
MIXING
SIMULATION
SPECTROSCOPY
MATHEMATICAL MODELS