Decay of 160Er* in 16O + 144Nd and 64Ni + 96Zr Fusion Reactions


N. G. Nicolis
J. L. Barreto
D. G. Sarantites
R. J. Charity
L. G. Sobotka
D. W. Stracener
D. C. Hensley
J. R. Beene
C. Baktash
M. L. Halbert
M. Thoennessen
Abstract

The population of evaporation residue entry states in the decay of the compound nucleus 160Er*(54 MeV) is investigated in a cross-bombardment employing the reactions 160 + 144Nd and 64Ni + 96Zr. Evaporation residue cross sections and entry state 7-ray fold distributions of the dominant exit channels were obtained for each reaction, using a 4π 7-ray detection system. An entrance-channel dependence of the 7-ray fold distributions of the xn products is observed. This effect is described successfully by the statistical model making use of compound nucleus angular momentum distributions obtained with a fusion model that provides a good description of the bombarding energy dependence of fusion data for both reactions. In accordance with recent findings on the decay of 164Yb*, it is suggested that the observed differences in the population of the dominant exit channels originate from the primary spin distributions rather than a possible dependence of the compound nucleus decay on the formation mode.

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