The ⁴He⁺ ion population decay under different Ne pressures (a) and the corresponding decay rates plotted against Ne number densities (b)

Figure 4. The ⁴He⁺ ion population decay under different Ne pressures (a) and the corresponding decay rates plotted against Ne number densities (b). The rate coefficient found in (b) is used to estimate k_loss for CH₄.

Abstract

We report our measured values for the sum of single and double charge transfer rate coefficients between ³He^{2 +} and H₂, CH₄, N₂ and CO. Our values are 2.4 ± 0.2 × 10⁻⁹ cm³ s⁻¹ for H₂, 6.3 ± 0.9 × 10⁻⁹ cm³ s⁻¹ for CH₄, 4.0 ± 0.3 × 10⁻⁹ cm³ s⁻¹ for N₂ and 4.7 ± 0.4 × 10⁻⁹ cm³ s⁻¹ for CO. The values are obtained at equivalent temperatures of 1200–2400 K.