Paper is devoted to development of the potential barrier model allowing to take into account the interaction between elastic reflection of particles and plasmatron walls. The coaxial magneto-plasma accelerator which has been put into practice is considered.Plasma clot change of speed and weight depending on the coordinate determined by both power characteristics and gas dynamic regularities of hypersonic jet currents in the cylindrical channel was investigated in the accelerator. Potential function and force field type modeling spatial restriction of plasma particles scattering is presented. Dynamics ofcharged particles distribution in electromagnetic field andthe plot of energy balance taking into account the erosion of channel walls have been presented. The developed model of the coaxial magneto-plasma accelerator taking into account an erosion caused by particles distribution on a low-frequency helixhas been shown.Low-frequency helixpath motion is presented as superposition of longitudinal and transverse motions. Differential equations were solved using the fourth-order Runge-Kutta fixed-step method.