Electron capture by heavy multicharged ions from atomic hydrogen at low velocities

Total cross sections for capture of an electron by ${\mathrm{Xe}}^{q+}\left(2\mathrm{}\le q\le 12\right)$, ${\mathrm{Ar}}^{q+}\left(2\mathrm{}\le q\le 9\right)$, and ${\mathrm{Fe}}^{q+}\mathrm{}(q=5,6\mathrm{})\mathrm{}$ colliding with atomic and molecular hydrogen have been measured for velocities between ${10}^7$ and ${10}^8$ cm/s. The cross sections vary from below 1 × ${10}^{-16\mathrm{}}$ ${\mathrm{cm}}^2$, with the measured values for $q\ge 4$ all greater than 37 × ${10}^{-16\mathrm{}}$ ${\mathrm{cm}}^2$. The cross sections are independent of ionic species for a given $q$ and are generally constant with changing velocity. The cross sections increase linearly with $q$ up to $q=9\mathrm{}$, but for the highest-charge states $q=9-12\mathrm{}$, the data suggest that the cross sections do not continue to increase as rapidly with increasing $q$.