36th International Field Emission Symposium
J. Phys. Colloques 50 (1989) C8-171-C8-174
DOI: 10.1051/jphyscol:1989830
INSTABILITIES IN LIQUID METAL ION EMITTERS
G.L.R. MAIRUniversity of Athens, Department of Physics, Division of Mechanics, Panepistimiopolis, GR-157 83 - Zografos, Athens, Greece
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.