Production of atomic negative ion beams of the Group IA elements

This paper reports on a method developed which enables the direct sputter generation of atomic negative ion beams of all members of the Group IA elements (Li, Na, K, Rb, and Cs). The method consists of the use of sputter samples formed by pressing mixtures of the carbonates of the Group IA elements and 10% (atomic) Cu, Ag, or other metal powder. The following intensities are typical of those observed from carbonate samples subjected to ∼3 KeV cesium ion bombardment Li-: ≥0.5 μA; Na-: ≥0.5 μA; K-: ≥0.5 μA; Rb-: ≥0.5 μA; Cs-: ≥0.2 μA