INSTABILITIES IN LIQUID METAL ION EMITTERS

Abstract
As the voltage in a liquid metal ion source is raised above onset, a level of current is reached where the liquid cone-shaped anode begins to vibrate under the competing influences of electrostatic and surface tension forces. At this point, µs oscillations appear in the current. In this regime, break-up of the jet-like apex region of the cone, with concomitant droplet emission, is naturally enhanced ; however, the instability growth rates involved in this process are a few orders of magnitude higher than the 1 MHz deduced from current oscillograms and emission frequency spectra.