Analysis of Positive Ions Emitted by a new Source

Abstract

Certain iron oxide crystals containing about one percent of some alkali metal or alkaline earth have been developed by the Fixed Nitrogen Research Laboratory for use as catalysts in the synthesis of ammonia. It has been found that these substances also have great experimental utility as constant and abundant emitters of positive ions. The writers have tested various methods of mounting and heating these emitters. They have also analyzed their emission by the use of a mass spectrograph which has been described by Smyth. Separate catalyst samples containing respectively Na, K, Rb, Cs, Mg, Ca, and in one case both Ba and Sr have been shown in this way to emit only the corresponding singly charged positive ion. No doubly charged ions were observed, nor any ions of the other elements composing the catalysts. The alkali metal ions were emitted at lower temperatures than the alkaline earth ions. Particularly in the case of the latter, a preliminary treatment consisting of reduction at red heat in an atmosphere of hydrogen increased the emission.Emission from hot platinum was also observed consisting of ${\mathrm{Na}}^{+}$ and ${\mathrm{K}}^{+}$ ions. This was a surface effect and diminished rapidly with time.