Non-invariance of both magnetic fluxes within flux tubes and global helicities in an ideal plasma and numerical demonstrations of generalized self-organization theory
KONDOH Yoshiomi, SERIZAWA Shunsuke, TAKAHASHI Toshiki1), James W. Van Dam 2)
1)Dept. of Electronic Engineering, Gunma University, Kiryu, Gunma 376-8515, Japan
It is proved that when we correctly use the full generalized Ohm's law instead of the simplified Ohm's law, both magnetic fluxes within flux tubes and global helicities (including the magnetic helicity and the self-helicity) are not invariant, even in an ideal MHD plasma. The identity of a flux tube cannot be maintained in a flowing turbulent plasma, even if the plasma itself is ideally conducting. The result is that topological quantities are not preserved during the turbulent flow of an ideally conducting plasma. This removes the physical basis for self-organization theories based on the concept of frozen-in magnetic field lines. It is also showed that the time rate of change of the self-helicity Ks and the time rate of change of the magnetic and kinetic energies Wm+k have exactly the same power-law dependence on the fluctuation wave number. This result implies that selective decay between Ks and Wm+k does not occur. Hence, theories based on helicity invariance have questionable relevance to relaxation and self-organized states in experimental plasmas.
References
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