Elastic scattering of protons from hydrogen atoms at energies 15-200 keV

Differential and integrated cross sections for the elastic process ${\mathrm{H}}^{+}+\mathrm{H}\mathrm{}\left(1s\right)\mathrm{}\to {\mathrm{H}}^{+}+\mathrm{H}\mathrm{}\left(1s\right)\mathrm{}$ were calculated with the use of results of coupled-state calculations in the energy range 15-200 keV. Results are presented and, at 60 keV, compared favorably with preliminary experimental data. The asymptotic form of the elastic amplitude for $b\gg a_0$ (where $b$ is the impact parameter) is derived for the two cases $\lambda \ll 1$ and $\lambda \gg 1$, where $\lambda$ is the ratio of the collision duration to the orbital period. The asymptotic form for $\lambda \gg 1$ provides a useful test on the numerical accuracy of the amplitudes.