| 摘要 |
<PICT:1070406/C6-C7/1> In a method of generating an alkali metal vapour for use in coating photo-cathodes, an electrolyzing current is passed through a body of carrier material containing ions of the alkali metal, while heating a portion of the body. In particular, an electrolyzing current may be passed between inner and outer helical electrodes 3, 2 provided on a tubular body of alumina, which is either impregnated with a solution of caesium carbonate, or which has been dipped in a molten glass comprising equal weights of silica, boric acid and caesium carbonate. Alternatively, two interwound helical electrodes are embedded in a tubular body formed by electrophoresis of a suspension of alumina in a solution of sodium hydroxide. The body may be heated by passing a heating current through one of the electrodes, or by induction heating, or infrared radiation. Specific examples are given. |
