||Secondary instabilities in the collisionless Rayleigh-Taylor instability: Full kinetic simulation
Umeda, TakayukiWada, Yasutaka
112117 , 2016-11-18 , AIP Publishing
The nonlinear evolution of the Rayleigh-Taylor instability (RTI) at a density shear layer transverse to magnetic field in collisionless plasma is investigated by means of a fully kinetic Vlasov simulation with two spatial and two velocity dimensions. The primary RTI in the MHD regime develops symmetrically in a coordinate axis parallel to gravity as seen in the previous MHD simulations. Small-scale secondary instabilities are generated due to secondary velocity shear layers formed by the nonlinear development of the primary RTI. The secondary instabilities take place asymmetrically in the coordinate axis parallel to gravity. It is suggested that these secondary instabilities correspond to the electron Kelvin-Helmholtz instability generated by the electron velocity shear, whose development depends on the polarity of the inner product between the magnetic field and the vorticity of the velocity shear layer.