In the 2014 year’s campaign of Experimental Advanced Superconducting Tokamak (EAST), a series of Magnetohydrodynamics (MHD) instabilities were observed as the launching of Neutral Beam Injection (NBI), the most interesting one of which is the neoclassical tearing mode (NTM). Evidence clearly shows that a kink mode present after a strong sawtooth-like (ST-like) crash leaves a perturbation near t...

The weakly non-linear interaction of slow magnetoacoustic and torsional Alfvén waves propagating along an unperturbed poloidal magnetic field in a stellar interior is studied in the high plasma β limit. It is shown that slow magnetoacoustic waves parametrically drive torsional modes with the half frequency and wave number. Therefore global slow magnetoacoustic waves which have a radial velocity...

Whistler-mode wave packets with fields exceeding the ambient dc magnetic field have been excited in a large, high electron-beta plasma. The waves are induced with a loop antenna with dipole moment either along or opposite to the dc field. In the latter case the excited wave packets have the topology of a spheromak but are propagating in the whistler mode along and opposite to the dc magnetic fi...

The properties of linear Alfvén, slow, and fast magnetoacoustic waves for uniform plasmas in relativistic magnetohydrodynamics (MHD) are discussed, augmenting the well-known expressions for their phase speeds with knowledge on the group speed. A 3 + 1 formalism is purposely adopted to make direct comparison with the Newtonian MHD limits easier and to stress the graphical representation of their...

Abstract We present high-resolution 2D and 3D simulations of magnetized decaying turbulence in relativistic, resistive magnetohydrodynamics. The show dynamic formation large-scale intermittent long-lived current sheets being disrupted into plasmoid chains by the tearing instability. These are locations enhanced magnetic-field dissipation heating plasma. find magnetic energy spectra ∝ k −3/2 , t...

The saturation of the tearing mode in a plasma column is investigated in the framework of the resistive magnetohydrodynamics approximation. In particular, a perturbative procedure is adopted to evaluate the structure of the magnetic island in three relevant physical conditions, depending on the model for the evolution of the resistivity, which may be affected by the growth of the mode. In cylin...

Black hole accretion flows are the hot, magnetized, turbulent plasma that surround black holes in astrophysical settings and in some cases make them the most luminous objects in the universe. I review recent developments in the numerical modeling of these plasmas. For weakly radiating flows it is now possible to follow the dynamics of the plasma by integrating the equations of general relativis...

A Sweet-Parker-type scaling analysis for asymmetric antiparallel reconnection in which the reconnecting magnetic field strengths and plasma densities are different on opposite sides of the dissipation region is performed. Scaling laws for the reconnection rate, outflow speed, the density of the outflow, and the structure of the dissipation region are derived from first principles. These results...