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Nano-Wrinkles, Compactons and Wrinklons Associated with Laser-Induced Rayleigh-Taylor Instability: I. Bubble Environment

We study dynamics, structure and organization of the new paradigm of wave-wrinkle structures associated with multipulse laser-induced Rayleigh-Taylor (RT) instability in the plane of a target surface in the circumferential zone (C-zone) of the spot. Irregular target surface, variation of the fluid layer thickness and of the fluid velocity affect the nonlinearity and dispersion. The fluid layer inhomogeneity establishes local domains arranged (organized) in the «domain network». The traveling wave-wrinkles become solitary waves and latter on become transformed into stationary soliton wave-wrinkle patterns. Their morphology varies in the radial direction of Gaussian-like spot ranging from the compacton-like solitons, to the aperiodic rectangular waves (with rounded top surface) and to the periodic ones. These wave-wrinkles may be successfully juxtapositioned with the exact solution of the nonlinear differential equations formulated in the Kadomtsev-Petviashvili sense taking into account the fluid conditions in particular domain. The cooling wave that starts at the periphery by the end of the pulse causes sudden increase of density and surface tension: the wave-wrinkle structures become unstable what causes their break-up. The onset of solidification causes formation of an elastic sheet which starts to shrink generating lateral tension on the wave-wrinkles. The focusing of energy at the constrained boundary causes the formation of wrinklons as the new elementary excitation of the elastic sheets.

Laser-matter interaction ; Rayleigh-Taylor instability ; Nonlinear waves ; Partial differential equations ; Solitary waves ; Compactons ; Wrinklons

PUBLISHER: Cambridghe University Press