Critical Analysis of the Modified Firsov Model II. Sensitivity to the Average Speed of Atomic Electrons

摘要

Cheshire's modification to the Firsov model for calculating the low-velocity electronic stopping cross section (S/sub e/) is shown to be highly sensitive to the use of an average () rather than a r.m.s. speed (v/sub rms/) for atomic electrons in the evaluation of S/sub e/. We demonstrate that a reduction by a factor of approx. 1/2 in the predicted values for S/sub e/ is generally observed when one uses as prescribed by the original theory, instead of v/sub rms/ as is commonly used in the calculations. The results of this study are compared with experimental data for amorphous carbon targets as well as for channeling measurements in the <110> direction for silicon crystals. A brief discussion is presented regarding the importance of the other factors that could affect the outcome of the calculations. (ERA citation 04:055647)