The Stopping Powers of Various Elements for Protons of Energies from 400 to 1050 kev

The proton-stopping powers of the elements nitrogen, neon, argon, krypton, xenon, nickel, and copper are reported in the energy range from 400 kev to 1050 kev. Comparisons are made with results of other experimental work and with theory. The measured stopping powers show a dependence on particle velocity and on the atomic number of the stopping element in general conformity with the theory of N. Bohr. For proton energies below 700 kev, the ratio of atomic stopping power to $Z^{\frac{1}{3}}$ for nickel and copper is lower than the corresponding ratio for the gases. Energy loss straggling is reported for nickel and copper and is of the same order of magnitude as theory predicts.