Transition to chaos in magnetized, weakly coupled plasmas

Andrea Carati; Francesco Benfenati; Alberto Maiocchi; Luigi Galgani; Matteo Zuin

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arXiv · 1209.4289

Transition to chaos in magnetized, weakly coupled plasmas

Andrea Carati·Francesco Benfenati·Alberto Maiocchi·Luigi Galgani·Matteo Zuin

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Abstract

We report the results of numerical simulations for a model of a one component plasma (a system of N point electrons with mutual Coulomb interactions) in a uniform stationary magnetic field. We take N up to 512, with periodic boundary conditions, and macroscopic parameters corresponding to the weak coupling regime, with a coupling parameter \Gamma=1/64. We find that a transition from order to chaos takes place when the density is increased or the field decreased so that the ratio \omega_p/\omega_c between plasma and cyclotron frequencies becomes of order 1 (or equivalently the ratio r_L/\lambda_D between Larmor radius and Debye length becomes of order 1). The result is in agreement with the theoretical prediction obtained in [1], on the basis of an old estimate of Iglesias, Lebowitz and MacGowan [2] for the intensity of the electric field acting on one electron and due to all the other ones. A comparison can be made with the threshold obtained from kinetic theory arguments, which corresponds to the condition \nu_{ee}/\omega_c=1, where \nu_{ee} is the electron collision frequency. The latter threshold has a completely different dependence on the physical parameters and, for \Gamma=1/64, gives a critical value of \omega_p about 80 times larger.

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Andrea Carati, Francesco Benfenati, Alberto Maiocchi, Luigi Galgani, Matteo Zuin. 2012-09-19. Transition to chaos in magnetized, weakly coupled plasmas. https://arxiv.org/abs/1209.4289

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