The nonlocality of the imaginary part of the microscopic optical potential is investigated for neutron elastic scattering on ${}^{16}\mathrm{O}, {}^{40}\mathrm{Ca}, {}^{48}\mathrm{Ca}$, and ${}^{208}\mathrm{Pb}$ at incident energies up to 30 MeV. The potential is derived within the particle-vibration coupling framework using fully self-consistent Skyrme-Hartree-Fock plus random-phase approximation (RPA) calculations with the SLy5 interaction, without ad hoc adjustable parameters. By fitting the nonlocality coordinate dependence of the absorptive potential $W(R,s)\equiv \mathrm{Im}\mathrm{\Delta }\mathrm{\Sigma }$, where $\mathrm{\Delta }\mathrm{\Sigma }$ is the dynamical part of the nucleon self-energy, to a Gaussian form at representative volume and surface radial positions, we extract the radius- and energy-dependent nonlocality function $\beta (R,E)$, whose values range from 1.01 to 2.03 fm, with a clear dependence on radial position, incident energy, and target mass. These results demonstrate that, for the absorptive part of the optical potential, a single universal constant such as the Perey-Buck value $\beta =0.85\mathrm{fm}$ cannot capture the radial, energy, and target-mass dependence of the nonlocality, and that nucleus-dependent, energy-dependent, and radially resolved descriptions of the absorptive potential $W$ are required for precision nuclear reaction calculations.

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• Elastic scattering reactions
• Models & methods for nuclear reactions
• Nuclear reactions
• Nuclear structure & decays
• Nucleon induced nuclear reactions