We present measurements of the stopping power of 800-keV ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ ions channeled along the Si〈100〉 axis, as a function of the incidence angle. We compare the experimental results with theoretical calculations by using the impact-parameter-dependent energy loss obtained from the solution of the time-dependent Schrödinger equation through the coupled-channel method. This nonperturbative calculation provides reliable energy-loss results which are in good agreement with the experimental results.

DOI:https://doi.org/10.1103/PhysRevB.55.4332