MIYAKE Kiyoshi Hitachi Ltd., Hitachi Res.Lab., Senior Researcher, 日立研究所, 主任研究員
SASAO Mamiko Natl.Inst.for Fusion Science, Ass.Prof., 助教授 (00144171)
WADA Motoi Doshisha Univ., Dept.of Electronics, Ass.Prof., 工学部, 助教授 (30201263)
A simple and small ion source (-1 cm^3) was developed to produce negative ions of even those elements having electron affinity less than -1 eV.A powdery sample (-10 mg) deposited on a gauze (G, -0.1 cm^2) was bombarded with electrons (up to -3 mA and -300 eV) emitted from a filament (F). The ions desorbed from G were easily extracted because F was mounted beneath G.Those ions of H^-, D^-, Li^-, Cl^-, Na^-, F^- and Ag^- were readily produced from various samples such as alkali hydrides and halides. The total ion current, its density and the ion yield (ion to electron current ratio) of H^- from NaH, for example, were as large as -0.1 mA, -1 mA cm^<-2> and -1%, respectively, although the electric power to heat F was only -5 W.Similarly, H^+ was readily produced. Introduction of H_2 had little effect upon the yield of H^<(〕SY.+-.〔)>.