Mass-Spectra of Helium and Oxygen

Abstract

IN the course of my analyses of leads of different origins I have had opportunity of making some interesting observations on these two elements. While preparing a new discharge tube by preliminary running, a mixture of helium and oxygen was used and a search was made for the line due to He⁺⁺. The occurrence of doubly charged helium atoms in the discharge was inferred during the early work of Sir J. J. Thomson¹ and has recently been very beautifully demonstrated by Conrad,² but the evidence in each of these cases was indirect, namely, the prolongation of the normal helium parabola. All attempts so far made to photograph the line of He⁺⁺ as a satellite of the line H₂ by means of the mass-spectrograph have been unsuccessful.