The fractions in dispersive of the volume and surface absorption potential integral to the total real volume potential integral, were evaluated numerically for neutron-nucleus interaction. The dispersive fraction values have been adopted in modifying the accuracy of the optical potential of the reaction, which in turn improved the calculated cross-section for neutron-nucleus interaction in accordance with published experimental measurements. The use of dispersive fraction to the potential integral was applied for the (n+99Tc) reaction and the calculated cross-sections were compared with published works in neutron energy 30MeV.