Experimental Study of Photoemission from Glass Dust

Wednesday, 17 December 2014
Jiri Pavlu, Libor Nouzak, Zdenek Nemecek and Jana Safrankova, Charles University, Prague, Czech Republic
Solar radiation, especially its UV part, is considered as a main contributor to the space dust charging. On the other hand, the study of photoemission from a majority of space-related materials is difficult because the surface of insulators is quickly charged. We present experimental observations of photoemission charging of glass dust grains that could serve for example as a lunar regolith substitute. A single grain is kept in a 3D electrodynamic trap and a temporal evolution of the grain charge and other quantities are determined. Differentially pumped (He or Ar) discharge lamp is employed as a source of the UV radiation. Besides dynamic observations, we estimate the glass grain work function to be about 4.7 eV.