Role of N/Z in giant dipole resonance γ rays as a probe of post-saddle nuclear dissipation

Using a Langevin model, we calculate the post-saddle giant dipole resonance (GDR) γ-ray multiplicity of the heavy nuclei 240Cf, 246Cf, 252Cf, and 240U at various post-saddle dissipation strengths. We find that with increasing the neutron-to-proton ratio N/Z of the Cf system, the sensitivity of the post-saddle γ emission to the dissipation strength decreases significantly, and it is insensitive to nuclear dissipation for the case of the high N/Z240U. The results suggest that in experiments to accurately obtain information of the post-saddle dissipation strength by measuring the GDR γ-ray multiplicity evaporated during the fission process of heavy nuclei, it is best to populate compound systems with low N/Z.