We present cross section experimental data required for modeling beam production, attenuation and energy loss in the heavy-ion beam probe technique, namely, electron-loss cross sections for anionic gold projectiles and Ar and N2 targets in the energy range from 30 keV to 1 MeV. The results agree well with low-energy measured values from the literature for the Ar target. The present results are also compared with literature results for the H− projectile and the Ar target, displaying similar velocity dependences. This similarity led to the use of a simple semi-classical model to calculate the projectile-electron-loss cross sections in a wide energy range. This model employs the total scattering cross sections for free electrons and the momentum distribution of the Au− electrons. The present experimental results are in good agreement with this model, allowing a reliable estimate of the cross section values up to 100 MeV. Our results indicate that previously calculated cross sections are overestimated by at least a factor of two. This previous overestimation of electron-loss cross sections leads to significant errors in the modeling of charge-state fractions of gold beams, with consequences in the optimization of beam energy resolution and intensity for HIBP with megaelectronvolts gold beams.
State-selective electron capture by Ar from H*() and H(): implications for charge exchange recombination spectroscopy diagnostics