Rotational state populations in O16+154Sm near-barrier fusion

The ground state rotational band populations for the 4n evaporation channel have been measured at three O16 bombarding energies. The populations for the He4+166Er reaction, which populates the same residual nucleus at above-barrier energies, have also been measured to calibrate the statistical model which has been used to relate the observed populations to the compound nuclear spin distribution. The mean compound nuclear angular momenta are somewhat less than obtained in a previous gamma ray multiplicity investigation and are in better agreement with coupled channels calculations.