抄録
This article surveys the restricted fields with the properties related to isolated negative ions. The conception on the electron affinity and its determination methods are explained, especially the determination methods which have been developed recently, photodetachment by laser and charge exchange by cesium atoms are described relatively detailed. The formation processes of the negative ions are classified by three main processes, that are electron captures, ion-pair fomation and charge exchanges, and these individual processes are explained briefly. The exposition are also included the temperature effects for the negative ion formation by dissociative resonance electron capture.
Finally, as the problem should required near future, the formation procedures of the very intense deuterium negative ions for the negative ion based neutral beam injection into the devices of the magnetically confined fusion are reviewed.
