Abstract
The screw dynamo is a critical phenomenon—a self-excitation that occurs only when the magnetic Reynolds number (Rm) reaches some threshold value. Temporal magnetic field growth is shown to occur at Rm slightly smaller than this critical value. The appearance of temporal growth is also limited from below by the second critical value of Rm. If, however, a seed magnetic field is present permanently, and not just at the initial time of evolution, temporal subcritical magnetic field growth gives rise to a stationary magnetic configuration. This stationary magnetic field turns out to be particularly strong if the seed field in the form of a traveling wave coincides in phase velocity with the magnetic field that emerges in the presence of a self-excitation. The possibilities for detecting such a resonance in the subcritical regime of operation of an experimental setup based on the screw dynamo are considered.
Similar content being viewed by others
REFERENCES
E. Parker, Cosmical Magnetic Fields (Claredon, Oxford, 1979; Mir, Moscow, 1982).
Ya. B. Zel’dovich, A. A. Ruzmaikin, and D. D. Sokoloff, Magnetic Fields in Astrophysics (Gordon and Breach, New York, 1983).
Ya. B. Zel’dovich, Sov. Phys. JETP 4, 460 (1956).
D. D. Sokoloff, R. A. Stepanov, and P. G. Frik, Phys. Usp. 57, 292 (2014).
E. Yushkov, A. Lukin, and D. Sokoloff, Phys. Rev. E 97, 063108 (2018).
Yu. B. Ponomarenko, Prikl. Mekh. Tekh. Fiz., No. 6, 47 (1973).
A. Gailitis and Ya. Zh. Freiberg, Magn. Gidrodin., No. 2, 3 (1976).
A. Gailitis and G. Lipsbergs, Magnetohydrodynamics 53, 349 (2017).
P. Frick, V. Noskov, S. Denisov, et al., Magnetohydrodynamics 38, 143 (2002).
A. Gailitis, O. Lielausis, S. Dement’ev, et al., Phys. Rev. Lett. 84, 4365 (2000).
R. Stepanov, R. Volk, S. Denisov, et al., Phys. Rev. E 73, 046310 (2006).
S. A. Denisov, V. I. Noskov, R. A. Stepanov, and P. G. Frick, JETP Lett. 88, 167 (2008).
P. Frick, V. Noskov, S. Denisov, et al., Phys Rev. Lett. 105, 184502 (2010).
R. Khalilov, I. Kolesnichenko, and R. Stepanov, Magnetohydrodynamics 49, 73 (2013).
M. Peyrot, F. Plunian, and C. Normand, Phys. Fluids 19, 054109 (2007).
V. V. Titov, R. A. Stepanov, and D. D. Sokoloff, J. Exp. Theor. Phys. 126, 566 (2018).
F. Stefani, A. Giesecke, and T. Weier, Solar Phys. 294, 60 (2019).
A. Kalinin and D. Sokoloff, Magnetohydrodynamics 55, 193 (2019).
V. Noskov, R. Stepanov, P. Frick, et al., Magnetohydrodynamics 55, 149 (2019).
Funding
This work was financially supported by the Russian Science Foundation (project no. 18-41-06201).
Author information
Authors and Affiliations
Corresponding author
Additional information
Translated by V. Astakhov
Rights and permissions
About this article
Cite this article
Titov, V.V., Stepanov, R.A. & Sokoloff, D.D. Transient Regimes of the Screw Dynamo. J. Exp. Theor. Phys. 130, 287–292 (2020). https://doi.org/10.1134/S1063776120010100
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S1063776120010100