Kelvin-Helmholtz versus Hall magnetoshear instability in astrophysical flows

DANIEL GÓMEZ; CECILIA BEJARANO; PABLO MININNI

PHYSICAL REVIEW E

AMER PHYSICAL SOC

Lugar: New York; Año: 2014 vol. 89 p. 1 - 7

1539-3755

We study the stability of shear flows in a fully ionized plasma. Kelvin-Helmholtz is a well known, macroscopic and ideal shear-driven instability. In sufficiently low density plasmas, also the microscopic Hall magneto-shear instability can take place. We performed three-dimensional simulations of the Hall-MHD equations where these two instabilities are present, and carried out a comparative study. We find that when the shear flow is so intense that its vorticity surpasses the ion-cyclotron frequency of the plasma, the Hall magneto-shear instability is not only non-negligible, but it actually displays growth rates larger than those of the Kelvin-Helmholtz instability.