Slowing down of 2-11 MeV C-12, O-16, Si-28 and Cu-63 heavy ions through Si3N4 thin foil by using Time-of-Flight spectrometry

The stopping force and the energy-loss straggling of Cu-63, Si-28, O-16 and C-12 partially stripped heavy ions crossing silicon nitride foil has been determined over a continuous range of energies 2-11 MeV, by using a method based on the Heavy Ion-Elastic Recoil Detection Analysis (HI-ERDA) technique using a Time of Flight (ToF) spectrometer. The obtained energy loss straggling values corrected for non-statistical straggling and the thickness variation using the Besenbacher's method have been analyzed and compared with the corresponding computed values. For computed electronic straggling we have used alternatively the widely used formulations such as, the universal Bohr straggling deduced from the Bohr stopping model, and the Lindhard-Scharff formula including the Bunching effect given by Hvelplund-Firsov formula according to the Besenbacher approach. The aim of such comparison is to check the reliability and accuracy of the existing energy loss straggling formulations, in the light of the present experimental results. The experimental results of energy loss straggling of all ions are found to be greater than those predicted by the Bohr stopping model or Lindhard-Scharff prediction model. The introduction of the bunching effect improves, the comparison and gives an estimation of other effects such as charge exchange. (C) 2015 Elsevier B.V. All rights reserved