The energy transferred to a tungsten lattice under bombardment by noble-gas and nitrogen ions has been measured for energies between 25 and 600 eV. A linear relationship was found between the energy transferred and the initial kinetic energy over the entire range for Xe+ and Kr+ and between 150 and 600 eV for N2+ and 75 to 600 eV for He+. A nonlinear relationship was found for Ne+ and Ar+ over most of the energy range. The fractional energy transferred was found to be between 0.4 and 0.6 for all gases measured. It is shown that the experimental data can be qualitatively explained on the basis of the binary-collision model. © 1974 The American Physical Society.