Experimental observation and characterization of the magnetorotational instability

Daniel R. Sisan, Nicolas Mujica, W. Andrew Tillotson, Yi-Min Huang, William Dorland, Adil B. Hassam, Thomas M. Antonsen, Daniel P. Lathrop

Published 2004-02-25, updated 2004-06-29Version 2

Differential rotation occurs in conducting flows in accretion disks and planetary cores. In such systems, the magnetorotational instability can arise from coupling Lorentz and centrifugal forces to cause large radial angular momentum fluxes. We present the first experimental observation of the magnetorotational instability. Our system consists of liquid sodium between differentially rotating spheres, with an imposed coaxial magnetic field. We characterize the observed patterns, dynamics and torque increases, and establish that this instability can occur from a hydrodynamic turbulent background.