Enhanced Charging and Mobilization of Photoemitting Dust Particles in a Low-Density Plasma

We present the first observations of dust charging and mobilization in a combined vacuum ultraviolet (VUV) and plasma environment. It is experimentally demonstrated that exposing photoemitting dust particles to a low-density plasma enhanced the charge on the particles, accompanied by a significant increase in dust mobilization compared to VUV or plasma exposure alone. Measurements of the dust charge support a proposed ‘charge pumping’ mechanism, in which ambient electrons are collected by photoemitting dust surfaces, causing more photoelectrons to be pumped onto surrounding dust particles, increasing repulsive forces and leading to enhanced mobilization.