ENERGY-LOSS AND NUCLEON EXCHANGE IN THE REACTION OF KR-86 WITH ER-166

Projectile-like products from the reaction 86Kr on 166Er at 8.18 MeV/amu have been measured using a large-area position-sensitive ionization chamber. The observed element distributions for a given energy loss are found to be asymmetric. An analysis of the data in terms of the residual kinetic energy above the Coulomb barrier, however, yields symmetric and Gaussian-shaped element distributions. At large energy losses, the centroids of these Gaussian distributions exhibit a drift towards symmetric mass splits. The correlation between the variance of the element distribution σz2 and the number of exchanged nucleons Nex is discussed. The exchange mechanism, as described by a simple one-body dissipation model, can account for a large portion of the measured energy loss. © 1979.