Abstract: Knowledge of Ve-Fe/Pb differential cross sections for a^e energy below several tens of MeV scale is believed to be crucial in understanding supernova physics. In a segmented detector at a spallation neutron source, ve energy reconstructed from the electron range measurement is strongly affected because both multiple scattering and electromagnetic showers occur along the electron passage in target materials. In order to estimate these effects, a simulation study has been performed with a cube block model assuming perfect tracking precision. The energy spectrum distortion is observed to be proportional to the atomic number of the target material. Feasibility of unfolding the distorted ~ energy spectrum is studied for both Fe and Pb. An evaluation of the statistical accuracy attainable is therefore provided for a segmented detector.