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

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 tomore » benchmark computational models used in astrophysics and fusion research.« less
Authors:
 [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)
Publication Date:
OSTI Identifier:
1167484
Report Number(s):
LA-UR--15-20272
TRN: US1500372
DOE Contract Number:
AC52-06NA25396
Resource Type:
Technical Report
Resource Relation:
Related Information: Dissertation
Research Org:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
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