Time dependent radiation pressure and time dependent, 2D ionisation rate for heliospheric modelling

We present an analytical model of the time-dependent, small-amplitude deformation of a free liquid surface caused by a spatially localized, axisymmetric, pulsed or continuous, acoustic or electromagnetic radiation pressure exerted on the surface. By exactly solving the unsteady Stokes equation, we predict the surface dynamics in all dynamic regimes, namely inertial, intermediate and strongly damped regimes. We demonstrate the validity of this model in all dynamic regimes by comparing its prediction to experiments consisting of optically measuring the time-dependent curvature of the tip of a hump created at a liquid surface by the radiation pressure of an acoustic pulse. Finally, we present a numerical scheme simulating the behaviour of a fluid–fluid interface subjected to a time-dependent radiation pressure and show its accuracy by comparing the numerical predictions with the analytical model in the intermediate and strongly damped regimes.

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Remarks on the Abraham–Minkowski problem, in relation to recent radiation pressure experiments

International Journal of Modern Physics A ◽

10.1142/s0217751x19410033 ◽

2019 ◽

Vol 34 (28) ◽

pp. 1941003 ◽

Cited By ~ 1

Author(s):

Iver Brevik

Keyword(s):

Radiation Pressure ◽

Present Note ◽

Casimir Effect ◽

Surface Forces ◽

Electromagnetic Energy ◽

Time Dependent ◽

Minkowski Problem ◽

Focus Attention ◽

Dielectric Surfaces ◽

Lorentz Forces

The classic electromagnetic energy–momentum problem in matter (usually called the Abraham–Minkowski problem) has attracted increased interest, as is natural in relation to the several impressive radiation pressure experiments that have appeared recently. Our intention with the present note is to focus attention on some of these results, and also to give a warning against premature interpretations of the observations. One sees often in the literature that the observable deflections of dielectric surfaces are interpreted so as to mean that the so-called Abraham term is a chief ingredient. Usually this is not so, however. Most of the experimental results are actually explainable by the surface forces at the dielectric surfaces, eventually augmented by Lorentz forces in the interior, and do not involve the Abraham momentum as such. For concreteness we focus mainly on a simplified version of the experiment of Kundu et al. (2017), but extend the analysis somewhat by including time-dependent resonance phenomena. In a short appendix we discuss also the connection with the Casimir effect.

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