Operation of liquid–metalion sources based on palladium alloys that contain boron, arsenic, and phosphorus (singly or in combination) was studied. These sources, when run on refractory metal needles and heater ribbons, have exhibited high angular intensity (1.5–5 μA/sr), long lifetime (\u3e150 h), low energy spread (eV), and stable operation with extracted currents down to 2 μA
