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Surface modes and multi-power law structure in the early-time response of magnetic targets

Peter B. Weichman
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Abstract

It was recently demonstrated [P. B. Weichman, Phys. Rev. Lett. {\bf 91}, 143908 (2003)] that the scattered electric field from highly conducting targets following a rapidly terminated electromagnetic pulse displays a universal $t^{-1/2}$ power law divergence at early time. It is now shown that for strongly permeable targets, $μ_c/μ_b \gg 1$, where $μ_b$ is the background magnetic permeability, the early time regime separates into two distinct power law regimes, with the early-early time $t^{-1/2}$ behavior crossing over to $t^{-3/2}$ at late-early time, reflecting a spectrum of magnetic surface modes. The latter is confirmed by data from ferrous targets where $μ_c/μ_b = {\cal O}(10^2)$, and for which the early-early time regime is invisibly narrow.

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Peter B. Weichman. 2004-01-19. Surface modes and multi-power law structure in the early-time response of magnetic targets. https://doi.org/10.1103/physrevlett.93.023902

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