The γ-ray spectrum in the giant dipole resonance (GDR) region associated with the reaction ${}_{}{}^{40}{}_{}{}^{}$Ar${+}^{70}$Ge at 10 MeV/nucleon has been measured in coincidence with residues of the heavy composite systems whose excitation energy was $E^{\mathrm{*}}$=230 MeV. From the statistical-model analysis, it is deduced that the GDR strength is consistent with 100% of the energy-weighted sum rule, the energy is 16±1 MeV while the width is ${13}_{\mathrm{-}2}^{+1\mathrm{}}$ MeV. This value is not very different from the one measured at $E^{\mathrm{*}}$=130 MeV, thus pointing to saturation effects in the damping of the GDR.

• Received 14 November 1988

DOI:https://doi.org/10.1103/PhysRevLett.62.2080