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 ${\mathrm{He}}^{+}$+Ne→He+${\mathrm{Ne}}^{+}$+$h\nu$ 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 Å evidently arise from transitions in the short-lived He${\mathrm{Ne}}^{+}$ 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×${10}^{-15\mathrm{}}$ ${\mathrm{cm}}^3$/sec at a gas temperature of 300 K. In addition to charge transfer, a second associative reaction channel producing He${\mathrm{Ne}}^{+}$ ions is found to have an effective rate coefficient of about 2×${10}^{-16\mathrm{}}$ ${\mathrm{cm}}^3$/sec.