Abstrakt
Dust grains can be charged to a positive surface potential by various processes. Small grains or grains of irregular shapes can reach such high surface field even at the moderate potential, the field initiated self-discharging of such charged grains can be of high importance for determination of its equilibrium potential.
We present results obtained by in-situ charging experiments with a single glassy carbon dust grain trapped in the electrodynamic quadrupole. We investigated the field ion emission under various conditions.
The observed probability of ionization of particles leaving the grain surface is significantly higher than that of surrounding gas.