Isotope effect in yields of nuclear reactions

.S.D The analysis results of the isotopic yields for products obtained in reactions of protons at energies 0.66,1,8.1 G eV with separated tin isotopes are presented. The experim ental data are com pared in form ofreactionsofelem entcrosssections fortwo targetsofdi(cid:11) erent isotope com positions. The scaling behaviour have been shown in the dependence ofthis ratios from neutron and proton com position at the reaction products. The discussion of scaling param eters allows to explain the m echanism of light and m edium m ass fragm ent production.