Energy loss, dispersion and asymmetry in energy loss distribution curves of energetic ions in Terbium foils

Energy loss, dispersion (energy loss straggling) and asymmetry (skewness and kurtosis) of energy loss distribution curves of Li, C and O ions in varying thicknesses of terbium foils were measured. The measurements were performed, through transmission technique, by utilizing 15UD Pelletron accelerator at Inter-University Accelerator Centre (IUAC), New Delhi, India. These measured energy loss and straggling values were compared with the corresponding computed values adopting the most commonly used theoretical/semiempirical formulations. The purpose of this comparison was to identify the best theoretical formulation for the considered combinations. Benton and Henke formulation-based computed values showed better agreement with the measured energy loss values. Concerning energy loss straggling, Titeica theory's predicted values were found to be better. Asymmetric parameters (skewness and kurtosis) reveal that the shape of energy loss distributions of considered ions in terbium foils was mesokurtic-type Gaussian. The precise knowledge of these parameters is crucial for understanding energy loss distribution for considered ion-matter combinations. Further, these could be used as input in various computer codes (SIMNRA, RUMP and NDF) to simulate spectra obtained through different ion beam-based techniques. (author)