[en] Inclusive cross section of production isotopes from ¹H to ⁸Li with kinetic energy 10-50 MeV/N in collisions of 3.33 GeV/N α particles with Ag and Au nuclei are analyzed. Variation of coalescsence model is suggested to describe spectra in that energy range. In the model together with the usual parameter P₀ - the radius of coalescence sphere in momentum representation a new parameter Esub(c) is used. It characterizes Coulomb potential of the fragment source. To obtain spectra of nucleons from which fragments have been formed the experimnental ratio formed with the help of the found nucleon distributions give ⁶He, sup(6, 7, 8)Li spectra. Comparison of the results with experimental data shows a good agreement. The parameters P₀ and Esub(c) have been found and the simplest interpretation is considered. For α-particle source the value of charge number Zsub(r)=30 and 1.4 normal nuclear density value have been obtained