| dc.description |
The Born and closure approximations are used to obtain an expression (in the form of a series) for the dissociation cross section σ<sub>1</sub> for the process H<sub>2</sub><sup>+</sup> + He → H + H<sup>+</sup> + He. Taking the first term only of the series, and assuming the LCAO approximation for the H<sub>2</sub><sup>+</sup> wave function, that overlap terms can be neglected, and that the hydrogen and helium atoms are in their ground state after the collision, the high-energy limit for the dissociation cross section is found to be 1 59 × 10<sup>-14</sup>/E cm<sup>2</sup>, where E is the energy of the incident H<sub>2</sub><sup>+</sup> in keV, as compared with the experimental values 1 25 × 10<sup>-14</sup>/E cm<sup>2</sup>, or 1 10 × 10<sup>-14</sup>/E cm<sup>2</sup>. The effect of initial vibrational excitation of the H<sub>2</sub><sup>+</sup> is also examined, and found to increase σ<sub>1</sub> by up to 20%, comparable with the experimental results of Barnett and Ray, and McClure for the dissociation of H<sub>2</sub><sup>+</sup> in hydrogen gas. |
