Energy transfer in the reaction of He+ with O₂

The reactions of He+ ions with diatomic O2 molecules bear on the interesting problem of the escape of helium from the earth's atmosphere. Considerable effort [MacDonald, 1963; Rankama, 1963] has been put forth to establish the mechanism that deposits sufficient kinetic energy in He+ or He to account for the escape process. Nicolet [1961] noted that the rate of photoionization of helium was similar to estimated rates of helium escape. Hanson [1962] suggested that He+ might diffuse downward to altitudes at which molecular oxygen and nitrogen are present and give the He+ + O2 → HeO+ + O If stable HeO+ were produced, dissociative recombination HeO+ + e → He + O could occur, which would give sufficient kinetic energy to the product helium atom to account for its disappearance from the atmosphere.