Spectroscopic observations of the radiative charge transfer and association of helium ions with neon atoms at thermal energy

The radiation emitted by the radiative charge transfer He⁺+Ne{→}He+Ne⁺+hν has been observed with the use of a selected-ion drift apparatus in conjunction with spectroscopic instrumentation. The two observed emission features with wavelengths around 4100 and 4240 {} evidently arise from transitions in the short-lived HeNe⁺ excited molecular ion which is formed in the collision. Mass-spectrometric observations of the product ions indicated that the reaction occurred with a rate coefficient of 1±{}0.3×{}10^-15 cm³/sec at a gas temperature of 300 K. In addition to charge transfer, a second associative reaction channel producing HeNe⁺ ions is found to have an effective rate coefficient of about 2×{}10^-16 cm³/sec.