Considering energy dependence of the barrier radius in heavy-ion fusion
reactions, a modified Siwek-Wilczy\'{n}ski (MSW) fusion cross section formula
is proposed. With the MSW formula, the fusion barrier parameters for 367
reaction systems are systematically extracted, based on 443 datasets of
measured cross sections. We find that the fusion excitation functions for about
60% reaction systems can be better described by introducing the energy
dependence of the barrier radius which is due to the dynamical effects at
energies near and below the barrier. Considering both the influence of the
geometry radii and that of the reduced de Broglie wavelength of the colliding
nuclei, the barrier heights are well reproduced with only one model parameter.
The extracted barrier radius parameters linearly decrease with the effective
fissility parameter, and the width of the barrier distribution relates to the
barrier height and as well as the reduced de Broglie wavelength at energies
around the Coulomb barrier.Comment: 9 figures, 1 table, accepted for publication in Atomic Data and
Nuclear Data Table