Universal fit formula for electronic stopping of all ions in carbon and silicon

Electronic stopping power curves of light and heavy ions in C and Si have b een constructed over the energy interval of E/M similar to 0.01-100 MeV/amu by combining experimental data at low and high energies. An excellent fit is obtained by an analytical expression approximating the asymptotic laws a t high and low velocities and interpolating the range in between. The coeff icients of this polynomial function obey simple monotonic dependencies on t he atomic number of the projectile, so that the stopping power of any proje ctile in C and Si can be predicted over the whole energy interval with a pr ecision of 10% or better. These results will be compared to the data provid ed by TRIM95. (C) 1998 Elsevier Science B.V. All rights reserved.