He3+andHe4+in 300°K Helium Plasmas: Their Effect on Recombination Loss of Electrons

The work reported here establishes the existence of $\mathrm{He}_{3}^{}{}_{}{}^{+}$ and $\mathrm{He}_{4}^{}{}_{}{}^{+}$ at room temperature (300\ifmmode^\circ\else\textdegree\fi{}K) in a helium afterglow. The data presented in this paper indicate that the often-measured electron-ion recombination coefficient in 300\ifmmode^\circ\else\textdegree\fi{}K helium afterglows is mainly attributable to electron recombination with $\mathrm{He}_{3}^{}{}_{}{}^{+}$ rather than, as is usually assumed, with the dominant ion $\mathrm{He}_{2}^{}{}_{}{}^{+}$.