Proton-silicon interaction potential extracted from high-resolution measurements of crystal rainbows

This study provides a way to produce very accurate ion-atom interaction potentials. We present the high-resolution measurements of angular distributions of protons of energies between 2.0 and 0.7 MeV channeled in a 55 nm thick (0 0 1) silicon membrane. Analysis is performed using the theory of crystal rainbows in which the Molière's interaction potential is modified to make it accurate both close to the channel axis and close to the atomic strings defining the channel. This modification is based on adjusting the shapes of the rainbow lines appearing in the transmission angle plane, with the resulting theoretical angular distributions of transmitted protons being in excellent agreement with the corresponding experimental distributions.