Measurement of Charge Exchange betweenH2and Low-Energy Ions with Charge States35≤q≤80

Charge-exchange cross sections for collisions between ${\mathrm{H}}_2$ and ions with unusually low center-of-mass energies (≈6 eV) and high-charge states (${\mathrm{Xe}}^{q+}:35, 43\le q\le 46$, ${\mathrm{Th}}^{q+}:73\mathrm{}\le q\le 80$) have been measured using a Penning ion trap. A nondestructive measurement technique permitted both primary and product ion analysis. The data, averaged over the charge states indicated above, are consistent with a total cross section that scales linearly with ion charge $q$. The true double-capture cross section is found to be about 25% of the total cross section at high $q$. The results are compared to predictions of the absorbing-sphere model.