Simple and accurate spectra normalization in ion beam analysis using a transmission mesh-based charge integration

Accurate and reproducible determination of the number of impact ions is essential for quantitative IBA measurements. Herewith we present an in-beam charge-collection device, consisting of a tungsten mesh enclosed by two negatively biased annular electrodes and a shaping slit. The charge-collection efficiency was measured as a function of aperture bias and the reproducibility of charge collection at different bias voltages studied. Scanning transmission ion microscopy (STIM) was used to check the effect of beam scattering at the mesh on its energy distribution. The effect of the device on the primary beam energy distribution was calculated for the beams typically used in Rutherford backscattering spectroscopy (RBS) and elastic recoil detection analysis (ERDA). Excellent characteristics of the device were demonstrated.