Electronic stopping power and effective charge of 50- to 230-keVD+andHe+in carbon, aluminum, gold, and cesium

With 50- to 230-keV ${\mathrm{He}}^{+}$ and ${\mathrm{D}}^{+}$ ions, electronic stopping powers are measured in transmission through about-100-nm foils of carbon, aluminum, gold, and cesium. For hydrogen ions, the data agree with semiempirical fits of compiled experimental results by Andersen and Ziegler. In the case of helium ions there exists an agreement with corresponding fits by Ziegler for carbon and aluminum but not for cesium (the present results are 25% lower) and gold (the present results are 30% higher). With the use of the same target foil for measurements with ${\mathrm{He}}^{+}$ and ${\mathrm{D}}^{+}$ the corresponding stopping-power ratios taken at the same ion velocity show a strong dependence on target material projectile velocity.