ELASTIC STOPPING OF FAST HEAVY-IONS BY ELECTRONS IN SOLIDS

Stopping of fast heavy ions by electrons in solids is studied. The contribution of elastic (with respect to the bombarding ion) scattering is shown to dominate in the velocity interval Z//1**1**/**3 nu //0 less than nu less than Z//1**2**/**3 nu //0 ( nu //0 is the Bohr velocity, nu and Z//1 are the velocity and atomic number of the projectile). Known experiments show a more rapid increase of stopping cross-section with nu for velocities of the order of Z//1**1**/**3 nu //0 than the existing theories predicted. The authors explain such increases as due to elastic scattering, and analyze the velocity dependence of stopping cross-section for higher velocity values.