Abstract
A study of ternary recombination of He2+ ions with electrons was carried out using flowing afterglow apparatus equipped with axially movable Langmuir probe (FALP). The flow tube was cooled down to 77 K and the number density of helium buffer gas was varied in the range of $1\times 10^{17} cm^{-3}$ – $5\times 10^{17} cm^{-3}$.
At these conditions, there are three main processes of recombination – dissociative recombination, ternary recombination (helium assisted) and collisional radiative recombination - CRR (the third particle is an electron). We observed the dependence of effective recombination rate coefficient αeff on helium buffer gas density with the ternary rate coefficient $K_He = (9.0 \pm 3.0)\times 10^{-26} cm^6s^{-1}$ while the extrapolation of this dependence towards low helium density gives the value of ternary recombination rate coefficient of CRR of He2+ ions with electrons $K_{CRR}=(2,2\pm0.8)\times10^{-17}cm^6s^{-1}$.
These results are in good agreement with theoretical predictions.