Measurement of the stopping cross-sections of Cu, Ag and Au for 0.2-1.9 MeV He ions

The stopping cross-sections of Cu, Ag and Au are measured for He ions in the energy range 0.2-1.9 MeV by using three Rutherford backscattering methods. The reliability of each method is assessed by examining the expected deviations of measured data due to the approximation introduced in the procedure for the determination of the stopping cross-section. The measured cross-sections which have expected deviations smaller than 0.5% are fitted into the empirical formula of Eppacher and Semrad with the weighting factors based on the errors of the measurements. For Cu, Ag and Au, the stopping cross-sections deduced from the present work are in good agreement with the data of ZBL-85 within 2, 8 and 7%, respectively. The limitations of each method are considerably improved and reliable data of the stopping cross-sections are obtained. ((orig.))