Determination of non-Rutherford cross-sections from simple RBS spectra using Bayesian inference data analysis

Analysis of RBS and ERDA data relies first and foremost on knowledge of the relevant stopping power and scattering cross-sections. Scattering cross-sections in the non-Rutherford region are often used for enhanced sensitivity to light elements, or for instance in 4He-ERDA measurement of hydrogen. Accurate experimental cross-section values in the energy and scattering angle regions of interest to IBA are thus essential to much analysis work. We developed a new method to determine scattering cross-sections experimentally, which consists in collecting many RBS spectra at different energies, and analysing them taking the cross-sections as fitting parameter. High quality simulations of resonances is essential. A Bayesian inference analysis leads not only to the cross-section curve that best fits the data, but also leads to confidence limits on the results obtained. We apply the method to several (p,p) resonances, and compare them to the literature experimental and evaluated values.