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Title: The Destruction of 3He by Rayleigh-Taylor Instability on the First Giant Branch

Abstract

No abstract prepared.

Authors:
; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
908910
Report Number(s):
UCRL-CONF-230059
TRN: US200722%%968
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Conference
Resource Relation:
Conference: Presented at: IAU General Assembly 2006, Prague, Czech Republic, Aug 14 - Aug 25, 2006
Country of Publication:
United States
Language:
English
Subject:
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; RAYLEIGH-TAYLOR INSTABILITY; HELIUM 3; LAWRENCE LIVERMORE NATIONAL LABORATORY

Citation Formats

Eggleton, P P, Dearborn, D P, and Lattanzio, J C. The Destruction of 3He by Rayleigh-Taylor Instability on the First Giant Branch. United States: N. p., 2007. Web.
Eggleton, P P, Dearborn, D P, & Lattanzio, J C. The Destruction of 3He by Rayleigh-Taylor Instability on the First Giant Branch. United States.
Eggleton, P P, Dearborn, D P, and Lattanzio, J C. Fri . "The Destruction of 3He by Rayleigh-Taylor Instability on the First Giant Branch". United States. doi:. https://www.osti.gov/servlets/purl/908910.
@article{osti_908910,
title = {The Destruction of 3He by Rayleigh-Taylor Instability on the First Giant Branch},
author = {Eggleton, P P and Dearborn, D P and Lattanzio, J C},
abstractNote = {No abstract prepared.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Apr 06 00:00:00 EDT 2007},
month = {Fri Apr 06 00:00:00 EDT 2007}
}

Conference:
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  • We have found a deep-mixing process which occurs during First Giant Branch (FGB) evolution. It begins at the point in evolution where the surface convection zone (SCZ), having previously grown in size, starts to shrink, and it is driven by a local minimum that develops in the mean molecular weight as a result of the burning of {sup 3}He. This mixing can solve two important observational problems. One is why the interstellar medium (ISM) has not been considerably enriched in {sup 3}He since the Big Bang. The other is why products of nucleosynthesis such as {sup 13}C are progressively enrichedmore » on the upper FGB, when classical stellar modeling says that no further enrichment should take beyond the First Dredge-Up (FDU) episode, somewhat below the middle of the FGB.« less
  • Convolute laminations, ball-and-pillow structures, load casts, flame structures, and heavy mineral sags are thought to form from a gravitationally unstable gradient of bulk density, but little field data exist to test the hypothesis. The authors collected wavelengths, amplitudes, bed thicknesses, and grain sizes of deformation structures in 286 pairs of sand-mud beds, and compared the geometries to the solutions of the Rayleigh-Taylor theory for two layers with Newtonian viscosities. The data come from hummocky cross-stratified sequences in the Upper Cretaceous Parkman Sandstone Member, Elk and Big Horn basins, Wyoming, and Tertiary nearshore marine sediments from Mal Pais, Costa Rica. Stepwisemore » multiple regression reveals that 72.3% of the variance in wavelength or spacing, lambda, of the structures is accounted for by the thickness, h/sub 1/, of the overlying (denser) bed, and 7.8% is accounted for by the thickness, h/sub 2/, of the underlying bed. Although actual field geometries show denser layers of finite thickness loading less dense layers of finite thickness, wave numbers calculated as 2..pi..h/sub 2//lambda compare favorably with those predicted from the Rayleigh-Taylor theory where an infinitely thick denser layer of viscosity, ..mu../sub 1/, loads a lower layer of finite thickness and viscosity ..mu../sub 2/. The mean wave numbers are not statistically different for convolute laminations, flames, and ball-and-pillow structures. However, the mean values for load casts and convolute laminations are statistically different, suggesting that the sediment behaved hydroplastically during deformation, and that the load-cast spacings may not be adequately predicted by a model that assumes Newtonian viscosities for the involved sediments.« less
  • The aim of this paper is to report on some recent studies that were performed in order to further extend the understanding of the late time evolution of the Rayleigh-Taylor (RT) instability. We report results on: (a) Two-dimensional nonlinear interaction of a small number of modes: (b) Three-dimensional single mode and two-mode-coupling evolution as compared with 2D nonlinear results: (c) RT evolution in three-dimensional spherical geometry under conditions relevant to intertial confinement fusion targets. (AIP) [ital American] [ital Institute] [ital of] [ital Physics]
  • A two dimensional hydrodynamic study indicates that convectively unstable gradients which develop during core collapse and bounce give rise to large scale core overturn. It is also shown that the concomitant release of neutrinos can deposit large amounts of energy and momentum in the infalling envelope and give rise to a powerful supernova explosion.
  • Statistical theories for the outer envelope of the Rayleigh-Taylor mixing layer refer to a simplified dynamics of fundamental modes and their interactions. These modes are bubbles of light fluid entrained in the mixing layer between the undisturbed light and heavy fluids. The dynamics can be understood in terms of the motion of a single mode and the interactions between modes. The single mode dynamics has to be solved self-consistently in a background field of random bubbles. The dominant interaction is bubble merger, i.e., the spreading of larger bubbles at the bubble envelope. Merger leads to dynamically increasing length scales, andmore » thus to a dynamic renormalization of scaling dimensions. The mechanism for bubble merger is the differential motion of physically adjacent single bubble modes. This paper is focused on the above topics: single bubble motion, bubble interactions and statistical models. 10 refs., 4 figs., 2 tabs.« less