Stopping cross section in the low- to intermediate-energy range: Study of proton and hydrogen atom collisions with atomic N, O, and F

We report electron-nuclear dynamics calculations of energy loss, charge exchange, and nuclear, electronic, and total stopping cross sections for protons and hydrogen atoms incident on atomic nitrogen, oxygen, and fluorine targets for projectile energies from a few eV up to 25 keV. Particular emphasis is placed on the analysis of the impact parameter and charge-exchange dependence of the energy loss. It is found that at low energies the electronic stopping is not proportional to the projectile speed, but depends on the excitation spectrum of the target, manifested by having a threshold or a second maximum in the stopping cross section at low projectile energy. Agreement with other calculations and the available experimental data is good.