Bethe-Bloch stopping-power parameters for Mylar, Kapton, and Havar targets derived from measurements with proton,α-particle, and carbon-ion projectiles

Recently reported measurements of the stopping powers of Mylar, Kapton, Havar, and nickel for proton, {α}-particle, and carbon-ion projectiles have been analyzed with a modified Bethe-Bloch formalism in order to ascertain values of various parameters and to test the additivity rule with mean excitation energies thus obtained. Extracted values of this parameter exceeded additivity predictions by 8--17 % for Mylar and by 5--9 % for Kapton, whereas the alloy Havar yielded mean excitation energies within -4% to +5% of the additivity value.