| 摘要 |
1,088,268. Ion sources. COMMISSARIAT A L'ENERGIE ATOMIQUE. March 19, 1965 [March 27, 1964], No. 11756/65. Heading H1D. A thermionic ion source for use in mass spectrometry comprises a metallic heating filament coated with a layer of a refractory, stabilizing substance having a smooth surface, and an outer layer comprising a mixture of this substance and the sample to be analysed by mass spectrometry. The refractory substance reduces the rate of ion current decrease due to evaporation of the sample and may be TiP 2 O 7 , MgAl 2 O 4 , NiO or salts of Ca, Sr, Ba, Zr, Th and Hf. It may be deposited on a Pt, Re or W filament in the form of a gel and is subjected to slow calcination by passing a heating current through the filament. The outer layer is then applied and the aggregate is subjected to further calcination. The thickness of the filament coating may be between 0À2 and 1 mm., preferably 0À5 mm. |
