Experimental evidence for magnetorotational instability in a helical   magnetic field
  A recent paper [R. Hollerbach and G. Rudiger, Phys. Rev. Lett. 95, 124501 (2005)] has shown that the threshold for the onset of the magnetorotational instability (MRI) in a Taylor-Couette flow is dramatically reduced if both axial and azimuthal magnetic fields are imposed. In agreement with this prediction, we present results of a Taylor-Couette experiment with the liquid metal alloy GaInSn, showing evidence for the existence of the MRI at Reynolds numbers of order 1000 and Hartmann numbers of order 10. 
Frank Stefani, Thomas Gundrum, Gunter Gerbeth, G\"unther R\"udiger,   Manfred Schultz, Jacek Szklarski, Rainer Hollerbach