The Effect of External Magnetic Fields on the Hall Effect of a Dusty Plasma Tornado*

We present results from our experiment designed to characterize the way external magnetic fields influence the Hall Effect of a turbulent granular system, and we report on the measured voltage fluctuations. We agitated polystyrene particles in a vertical cylindrical annulus using a swirling flow of air, thus creating a model of a dusty plasma tornado. Because colliding particles lose or gain charge through the process of granular electrification, we observe a voltage difference between the concentric cylinders, confining the flow. The apparatus is placed inside of a vertical magnetic field of strength 0.62 T and aligned with the dipole. We observe a difference in voltage with varied strength of the magnetic field. The turbulent flow of collisionally charged particles produces a large fluctuation in voltage due to magnetic field. The nature of the spontaneous discharge produces random fluctuations, which are observed to be larger than the Hall Effect. This experiment has applications to systems undergoing granular electrification resulting in stochastic discharge.