Abstrakt
Ion field emission from dust grains was studied using several glassy carbon grains of different radii from 1.64 to 2.97 $\mu$m as dust samples. Each grain was stored in a quadrupole trap under UHV conditions for a long time (days) and charged by argon ions to a high surface potential.
When the ion gun was switched off the charged grain started to discharge spontaneously. We found out that the discharging process is a combination of field ionization and field desorption.
A simple model for ion field emission was developed and the model results were compared with the measured data. Influence of the ion penetration depth on the field ion emission is discussed and compared with different measurements of ion diffusion and consecutive desorption of the implanted ions