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Ablative Acceleration of Foils, Their Pulsations, and Interchange Instability

Published online by Cambridge University Press:  09 March 2009

N.A. Inogamov
N.A. Inogamov
Affiliation:
Landau Institute for Theoretical Physics, Kosygin Street, 2, 117334, Moscow, Russian Federation
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Abstract

The problem of hydrodynamic stability is important for inertial confinement fusion (ICF) systems based upon high compression of fuel before its ignition. This problem for the case of complicated multilayer foils has been studied here by a new approach describing the development of Rayleigh-Taylor or interchange instability in compressible media with inhomogeneous distribution of “entropy”s = ρ/ρk, ∂ where K = (∂ In ρ/∂ In ρ)s is an adiabatic derivative taken in the local hydrostatic values of ρ and ρ. Inhomogeneous distribution of s simulates the dynamics of development of perturbations of multilayer flyer foils and shells. Besides instability, the same approach has been used for analysis of ID pulsations of a levitated foil. The problem of pulsations is real in the case of foils. Indeed, (1) an ablative acceleration is equivalent to an effective gravity field, which causes the appearance of an atmospheric-type distribution of thermodynamic functions, (2) the duration of ablative flight of foil is at least several times larger than the time that is necessary for an acoustic wave to travel from one side of the foil to another side, and (3) there is a strong initial impulse that initiates the motion of foil. This impulse together with (1, 2) is a reason for the powerful pulsations of foils. The period of pulsations is defined by the velocity of sound in the foil material, which is dependent on the derivatives of an equation of state (EOS). The check of the derivatives gives us finer information concerning the current state of matter and the EOS than the usual measurements of material velocity and pressure that are rougher measures. Therefore, an analysis of pulsations seems to be a promising tool for tracking the dynamics of flyer foil and for the definition of thermodynamic properties of matter.

Type
Research Article
Information
Laser and Particle Beams , Volume 15 , Issue 4 , December 1997 , pp. 495 - 506
Copyright
Copyright © Cambridge University Press 1997

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References

REFERENCES

Agureikin, V.A. et al. 1984 Teplofizika visokikh temperatur 22, 964.Google Scholar
Anisimov, S.I. et al. 1984 Pis 'ma v JETP 39, 9.Google Scholar
Bluhm, H. 1996 Introduction to intense light ion beam generation and focusing. Report at the Inter-national Workshop dedicated to the Physics of High Energy Density in Matter.Google Scholar
Bud'ko, A.B. & Liberman, M.A. 1992 Phys. Fluids B4, 3499.CrossRefGoogle Scholar
Cox, J.P. 1980 Theory of Stellar Pulsation (Princeton University Press, Princeton, New Jersey).CrossRefGoogle Scholar
Kull, H.J. 1991 Physics Rep. 206, 197.CrossRefGoogle Scholar
Landau, L.D. & Lifshitz, E.M. 1974 Quantum Mechanics (Nauka, Moscow).Google Scholar
Letts, S.A. et al. 1994 ICF Quarterly Rep. LLNL 4, 54.Google Scholar
Marten, H. et al. 1996 Slowing down of an ablatively accelerated foil after impact of a stationary target. Report at the International Workshop dedicated to the Physics of High Energy Density in Matter.Google Scholar
McEachern, R. et al. 1993 ICF Quarterly Rep. LLNL 4, 25.Google Scholar
Meyer-Ter-Vehn, J. 1996 Fundamentals of ICF target physics. Report at the International Workshop dedicated to the Physics of High Energy Density in Matter.Google Scholar
Unno, W. et al. 1979 Nonradial Oscillations of Stars (University of Tokyo Press, Tokyo, Japan).Google Scholar