von Karman-Howarth Equation for Hall Magnetohydrodynamics: Hybrid Simulations

0506444 - ÚFA 2020 RIV US eng J - Journal Article
Hellinger, Petr - Verdini, A. - Landi, S. - Franci, L. - Matteini, L.
von Karman-Howarth Equation for Hall Magnetohydrodynamics: Hybrid Simulations.
Astrophysical Journal Letters. Roč. 857, č. 2 (2018), č. článku L19. ISSN 2041-8205. E-ISSN 2041-8213
Institutional support: RVO:68378289
Keywords : numerical methods * plasmas * solar wind
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 8.374, year: 2018
Method of publishing: Open access
https://iopscience.iop.org/article/10.3847/2041-8213/aabc06

A dynamical vectorial equation for homogeneous incompressible Hall-magnetohydrodynamic( MHD) turbulence together with the exact scaling law for third-order correlation tensors, analogous to that for the incompressible MHD, is rederived and applied to the results of two-dimensional hybrid simulations of plasma turbulence. At large (MHD) scales the simulations exhibit a clear inertial range where the MHD dynamic law is valid. In the sub-ion range the cascade continues via the Hall term, but the dynamic law derived in the framework of incompressible Hall-MHD equations is obtained only in a low plasma beta simulation. For a higher beta plasma the cascade rate decreases in the sub-ion range and the change becomes more pronounced as the plasma beta increases. This break in the cascade flux can be ascribed to nonthermal (kinetic) features or to others terms in the dynamical equation that are not included in the Hall-MHD incompressible approximation.
Permanent Link: http://hdl.handle.net/11104/0297687