Ion source of high brightness using liquid metal

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.