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.