Padé approximants from Born asymptotic cross-section expansions

Padé approximants are examined as a means for approximately summing the power-series expansions for inelastic Born cross sections developed in recent work. The advantages of the Padé cross section over the two-term series expansion in ${\left(\frac{v}{c}\right)}^{-2\mathrm{}}$ are indicated. Explicit calculations for the total electron-loss cross section for ${\mathrm{H}}^{-}$ ions incident on ${\mathrm{H}}_2$, He, and Ar are carried out. The results are compared with the available experimental data in the 10-keV to 1-MeV energy range and with the quasiclassical impulse approximation of Bates and Walker.