Energy Loss of Low Energy Protons and Deuterons in Evaporated Metallic Films

Abstract

The energy losses, the energy stragglings, and the charge-exchanges of protons and deuterons in the evaporated metallic films Be, Al, Cu, Ag, and Au were measured in the energy range of the incident particles from 7 to 40 keV. The experimental stopping cross-sections of Be, Al, Cu, Ag, and Au for protons are approximately proportional to V 0.8 and are also approximately proportional to square roots of the atomic numbers of the stopping substances. The electronic stopping cross-section of Cu for protons shows a good agreement, in the velocity scale, with that for deuterons measured with the same foil within the experimental error. The experimental energy straggling \(\varOmega^{2}/\varDelta E\) is proportional to E 0.8 and to the 0.68-th power of the atomic number of the stopping substance. The experimental stopping cross-sections and energy stragglings are compared with the Lindhard's theoretical calculations. The measured population ratios of hydrogen atoms to protons in the emergent beam were found to agree approximately with the theoretical calculations by Bohr and Lindhard.