Gas targets have been used to measure the scattering length in neutron-proton (n-p) scattering experiments. Changes in electron dynamics within the gas target have a negligible effect on the dynamics of nucleons. However, electron dynamics are sensitively related to the specific form of the n-p interaction during the scattering process. We propose a theoretical approach to explore electron dynamics and determine the parameters of the n-p interaction. This approach is based on a three-body scattering process involving a neutron, a proton and an electron. Numerical results indicate significant differences in electron dynamics with varying values of n-p interaction parameters, providing additional information beyond scattering cross-sections to accurately determine these parameters.