WEAKLY POPULATED MULTINUCLEON TRANSFER CHANNELS STUDIED WITH A NEW TIME-OF-FLIGHT MAGNETIC SPECTROMETER

A new time-of-flight spectrometer with magnetic quadrupoles has been d eveloped. Its high detection efficiency and resolution allows one to i dentify ions produced with low cross sections in a binary reaction. Th e study of multinucleon transfer channels in the system Ca-48 + Sn-124 revealed a large drift of the experimental total cross sections with respect to calculations which include independent single nucleon trans fer modes. Incorporating pair and cu-cluster channels into theory acco unts, at least qualitatively, for the discrepancies. New data coming f rom the study of Ni-64 + U-238 show the striking presence of -1 alpha, -2 alpha and -3 alpha channels, supporting once more the idea that cl uster degrees of freedom must be considered in a correct description o f the reaction mechanism.