Stopping powers of several composite materials for 2.4 and 3.5 MeV deuterons and 5.5 MeV α particles

Stopping powers of the alloys Havar, Mu Metal, and Permalloy 4750 have been determined for 2.4- and 3.5- MeV deuterons. Similar measurements were made with foils of Havar, Mu Metal, Teflon, and Mylar for ²⁴¹Am α particles. Mean excitation energies extracted from the data were compared with values obtained from Bragg's rule. Whereas results for Havar, Mu Metal, and Teflon generally agree with additivity predictions, the experiment-based mean excitation energy of Mylar lies 10% above, and that of Permalloy 4750 6% below, the Bragg's-rule calculation.