Simplistic shape and orientation fluctuation calculations are compared with the data for the system ${}^{28}\mathrm{Si}+{}^{58}\mathrm{Ni}$ at E(${}^{28}\mathrm{Si}$)$=100$ and 125 MeV. The collisional damping width (${\Gamma }_0$) is extracted under the shape fluctuation model analysis. A constant value of ${\Gamma }_0$ cannot reproduce the measured γ-spectra. The extracted value of ${\Gamma }_0$ is found to be independent of the average angular momentum $\langle J\rangle$, while showing a mild temperature dependence above an average temperature, $\langle T\rangle ~1.3$ MeV. Below, a very small value of ${\Gamma }_0~3.8$ MeV is found.

• Received 7 December 2005

DOI:https://doi.org/10.1103/PhysRevC.74.024608