Revelations from stopping power analyses

Recent measurements of the stopping powers of various composite-material targets have been analyzed in the presence of Barkas-effect and Bloch corrections in order to extract appropriate values of Bethe-Bloch parameters. Mylar, Kapton, and Havar targets have been studied in particular, primarily using measurements with light projectiles. The present investigation focuses on results for Havar analyses, where dispersion among sets of measurements appears to separate extracted parameter-values into at least two groups. An hypothesis pertaining to target properties is advanced in explanation. In another study, analyses of experimental results for alpha particle projectiles traversing Ti and V targets have yielded parameter-values reasonably consistent with expectation. Finally, the importance of including all pertinent correction terms when analyzing data with Bethe-Bloch stopping power theory is emphasized.