For the first time, the values of the atomic particle-solid body potential were obtained from experimental data on the energy spectra and angular dependences of backscattered particles. The proposed procedure for determining the potential has not previously been applied. It is shown that the obtained data do not depend on the potential approximation used. The interaction potential between an ion and a solid differs markedly from the potential describing collisions in the gas phase. The screening constant increases by 10-15%. The increase in screening is due to an increase in the density of the electron gas in the region between the incident particle and the scattering center.