skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Turbulent hydrodynamics experiments using a new plasma piston

Abstract

A new method for performing compressible hydrodynamic instability experiments using high-power lasers is presented. A plasma piston is created by supersonically heating a low-density carbon based foam with x-rays from a gold hohlraum heated to {approx}200 eV by a {approx}1 ns Nova laser pulse [E. M. Campbell et al., Laser Part. Beams 9, 209 (1991)]. The piston causes an almost shockless acceleration of a thin, higher-density payload consisting of a layer of gold, initially 1/2 {mu}m thick, supported on 10 {mu}m of solid plastic, at {approx}45 {mu}m/ns{sup 2}. The payload is also heated by hohlraum x-rays to in excess of 150 eV so that the Au layer expands to {approx}20 {mu}m prior to the onset of instability growth. The Atwood number between foam and Au is {approx}0.7. Rayleigh-Taylor instability, seeded by the random fibrous structure of the foam, causes a turbulent mixing region with a Reynolds number >10{sup 5} to develop between piston and Au. The macroscopic width of the mixing region was inferred from the change in Au layer width, which was recorded via time resolved x-radiography. The mix width thus inferred is demonstrated to depend on the magnitude of the initial foam seed. For a small initial seed,more » the bubble front in the turbulent mixing region is estimated indirectly to grow as {approx}0.036{+-}0.19 [{integral}{radical}(Ag)dt]{sup 2} which would imply for a constant acceleration 0.036{+-}0.019 Agt{sup 2}. More direct measurement techniques must be developed in larger scale experiments to remove potential complicating factors and reduce the error bar to a level that would permit the measurements to discriminate between various theories and models of turbulent mixing. (c) 2000 American Institute of Physics.« less

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [2]
  1. Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)
  2. Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States) (and others)
Publication Date:
OSTI Identifier:
20216075
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 7; Journal Issue: 5; Other Information: PBD: May 2000; Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; PISTONS; TURBULENCE; PLASMA; HYDRODYNAMICS; REYNOLDS NUMBER; PLASMA INSTABILITY; MIXING; NOVA FACILITY; LASER-PRODUCED PLASMA; EXPERIMENTAL DATA; THEORETICAL DATA

Citation Formats

Edwards, J., Glendinning, S. G., Suter, L. J., Remington, B. A., Landen, O., Turner, R. E., Shepard, T. J., Lasinski, B., Budil, K., and Robey, H. Turbulent hydrodynamics experiments using a new plasma piston. United States: N. p., 2000. Web. doi:10.1063/1.874177.
Edwards, J., Glendinning, S. G., Suter, L. J., Remington, B. A., Landen, O., Turner, R. E., Shepard, T. J., Lasinski, B., Budil, K., & Robey, H. Turbulent hydrodynamics experiments using a new plasma piston. United States. doi:10.1063/1.874177.
Edwards, J., Glendinning, S. G., Suter, L. J., Remington, B. A., Landen, O., Turner, R. E., Shepard, T. J., Lasinski, B., Budil, K., and Robey, H. Mon . "Turbulent hydrodynamics experiments using a new plasma piston". United States. doi:10.1063/1.874177.
@article{osti_20216075,
title = {Turbulent hydrodynamics experiments using a new plasma piston},
author = {Edwards, J. and Glendinning, S. G. and Suter, L. J. and Remington, B. A. and Landen, O. and Turner, R. E. and Shepard, T. J. and Lasinski, B. and Budil, K. and Robey, H.},
abstractNote = {A new method for performing compressible hydrodynamic instability experiments using high-power lasers is presented. A plasma piston is created by supersonically heating a low-density carbon based foam with x-rays from a gold hohlraum heated to {approx}200 eV by a {approx}1 ns Nova laser pulse [E. M. Campbell et al., Laser Part. Beams 9, 209 (1991)]. The piston causes an almost shockless acceleration of a thin, higher-density payload consisting of a layer of gold, initially 1/2 {mu}m thick, supported on 10 {mu}m of solid plastic, at {approx}45 {mu}m/ns{sup 2}. The payload is also heated by hohlraum x-rays to in excess of 150 eV so that the Au layer expands to {approx}20 {mu}m prior to the onset of instability growth. The Atwood number between foam and Au is {approx}0.7. Rayleigh-Taylor instability, seeded by the random fibrous structure of the foam, causes a turbulent mixing region with a Reynolds number >10{sup 5} to develop between piston and Au. The macroscopic width of the mixing region was inferred from the change in Au layer width, which was recorded via time resolved x-radiography. The mix width thus inferred is demonstrated to depend on the magnitude of the initial foam seed. For a small initial seed, the bubble front in the turbulent mixing region is estimated indirectly to grow as {approx}0.036{+-}0.19 [{integral}{radical}(Ag)dt]{sup 2} which would imply for a constant acceleration 0.036{+-}0.019 Agt{sup 2}. More direct measurement techniques must be developed in larger scale experiments to remove potential complicating factors and reduce the error bar to a level that would permit the measurements to discriminate between various theories and models of turbulent mixing. (c) 2000 American Institute of Physics.},
doi = {10.1063/1.874177},
journal = {Physics of Plasmas},
issn = {1070-664X},
number = 5,
volume = 7,
place = {United States},
year = {2000},
month = {5}
}