The　emission　properties　of　nanosized　scandia-doped　dispenser　cathodes　tested　in　open-structure　Pierce　electron　guns　are　reported　in　this　paper.　Over　100　A/cm(2)　and　over　80　A/cm(2)　space-charge-limited　current　densities　have　been　obtained　at　the　operating　temperatures　of　950　degrees　C(b)　and　1025　degrees　C(b)　for　cathodes　with　planar　emitting　surfaces　and　cathodes　with　concave　emitting　surfaces,　respectively,　at　rated　anode　voltages.