Monte Carlo simulations of the Lewis effect

Recent experiments measuring the thick-target yield curve of narrow resonances in (p, γ) reactions on²³Na,²⁶Mg and²⁷Al nuclei clearly show the Lewis effect. We have studied this effect theoretically on the basis of a Monte Carlo simulation of the nuclear and electronic energy loss curve in the target. We are able to reproduce the experimental data qualitatively. We discuss possible implications of precision measurements of the Lewis effect.