Inverse cascade in simulated MHD turbulence driven by small scale source of magnetic helicity

R. Stepanov^{1, 2} - V. Titov¹

¹ Institute of Continuous Media Mechanics, 1 Korolyov str., Perm 614013, Russia
² State National Research Polytechnical University of Perm, 29 Komsomolskii ave., 614990 Perm, Russia

Abstract
We simulate an inverse cascade in three-dimensional magnetohydrodynamic turbulence driven by a large scale non-helical energy forcing and a small scale source of magnetic helicity. In particular, the magnetic force applied is conservative and injects only magnetic helicity. Using direct numerical simulation, MHD turbulence with oppositely directed spectral fluxes of energy is obtained, and magnetic helicity coexists in the inertial range. The magnetic field energy can reach the same level of equipartition as in the well-known case of MHD turbulence with helical large-scale forcing. In the context of astrophysical dynamos, our results indicate that a large-scale dynamo can be affected by magnetic helicity generated at small scales. Kinetic helicity does not play any role in the process at all. Figs 4, Refs 17.