The kinetic energies of the plasma plume species and their control are critical to ensure the high quality of thin films grown by pulsed laser deposition. The maximum kinetic energies of ionic plasma species from different multicomponent materials, CaTiO₃, EuAlO₃, La_0.4Ca_0.6MnO₃, La_0.4Ca_0.6Mn_0.9Ru_0.1O₃, and YBa₂Cu₃O₇, have been analysed, revealing a wide range of energies of 100–700 eV. A direct relationship between the maximum kinetic energies and atomic masses has been found: the larger is the mass of an ion, the higher is its energy. This dependence varies with the kind of the ablated material and its slope is changing with laser fluence. The results are explained by the generation of a self-consistent ambipolar electric field in front of the expanding laser plume. The concept of a dynamic double layer has been considered, when heavier ions remain in the ambipolar field for a longer time as compared to lighter ions, thus resulting in stronger acceleration of heavy ions.