Dust mobilization in the presence of magnetic fields.

Abstract

We present a study of surface dust mobilization due to photoelectric charging in the presence of a magnetic field. Dust mobilization is observed to be inhibited in certain regions and is correlated with the orientation of the magnetic field. The recent patched charge model, which describes a mechanism for dust charging and mobilization, is extended to explain the effects of magnetic fields seen in our laboratory results. We propose that ambient electrons collected in photoemitting areas precipitate changes in the emission and reabsorption of photoelectrons inside microcavities between dust grains. This affects the charging, repulsion, and subsequent mobilization of the dust grains surrounding the microcavities. The magnetic field controls the movement of ambient electrons across the dusty surface, resulting in active and inactive regions of dust mobilization. Computer simulations show that regions of ambient electron accumulation as imposed by the magnetic field match the areas of high dust activity.