Answers are grounded in this paper and cite their sources.
The beam from an EHD ion source using liquid gallium has been shown to have a brigtness of 0.9×105 A cm−2 sr−1 at 21 kV and an energy spread of 12 eV at 10-μA total current. The effective source diameter was 0.2 μm as imaged by a 2-cm-long Einzel lens with a 0.12-mm aperture. Cesium was significantly poorer and mercury much poorer than gallium.
No takes yet. Share an insight, caveat, or question.
Krohn et al. (1975) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: