Intercomparison of atomic models for computing stopping parameters from the Bethe theory: Atomic hydrogen

The stopping cross section, the straggling parameter, and three higher moments over the energy-loss cross section have been evaluated for a moving point charge interacting with atomic hydrogen. The aim was to estimate the accuracy of predictions based on four commonly used models for computation of stopping parameters. The standard of reference was a straight evaluation of the Born approximation. All considered models, i.e., the dielectric theory, the binary-encounter model, the kinetic theory, and the harmonic-oscillator model, have been shown to be capable of providing reliable predictions within their respective regimes of feasibility, but distinct variations show up from lower to higher moments and from higher to lower projectile energy.