Plasma Physics Seminar ( Phys 769)

Andrew Tillotson   CANCELED Dept. of Physics, University of Maryland Modeling the Magnetorotational Instability in Nearly Inviscid Systems A question of considerable interest in the astrophysical community involves the mechanism of angular momentum transport through accretion disks.  Accretion disks, like many astrophysical flows, are nearly inviscid, and consequently, it is unlikely that purely hydrodynamic turbulence could cause the dissipation required for gas to flow onto the central object. However, when the gas is warm enough to become partially ionized, accretion disks become magnetohydrodynamic fluids. When threaded by a weak magnetic field, these rotating fluids can show signs of the magnetorotational instability (MRI), a popular and promising candidate for the explanation of this orbital angular momentum transport in accretion disks. Basic characteristics of MRI are presented, as well as strong evidence which has recently emerged from UMD that the MRI is observable in a laboratory setting. Simulation results, which have succeeded in reproducing some of the key MRI features, are also presented.