Helical MRI in MHD Taylor-Couette flow

Magnetorotational Instability (MRI) is believed to be one of the most important instabilities on astrophysical scales. However, it is very difficult to observe it in a laboratory experiment. One possibility is to use a Taylor-Couette setup (a flow between two concentric rotating cylinders) where a liquid metal alloy is used. Problems arise since such metals are characterized by very small magnetic Prandtl number and consequently vast rotation rates are necessary. In the PROMISE experiment a special helical configuration of the applied magnetic field was used in order to dramatically reduce rotation rates. We present numerical simulations and relate it to experimental results confirming the existence of MRI of this type.