Energy Loss and Stopping Power of ⁴He Ions in mylar Foils

The energy loss and stopping power of ⁴He ions in mylar foils were determined in a transmission geometry. The experimental stopping power data were compared to the previous measurements at higher energies. At lower energies, no previous measurements exist. The present results were also compared to the commonly used semiempirically theoretical predictions by Ziegler and Manoyan, and significant deviations were observed.