The effective optical potential of the electron–atom interaction in dense semiclassical helium plasma is derived. The Hartree–Fock, polarization, and exchange potentials consider the collective screening effect and the quantum-mechanical effect of diffraction. It was shown that when three components of the optical potential act together the characteristics of electron–helium scattering change significantly in comparison with results based on their separate involvement. The influence of the quantum-mechanical effect of diffraction was also discussed.

We present the effective optical potential of the interaction of an electron with an atom in dense semiclassical plasma of noble gases. This potential takes into account the collective screening effect and the quantum mechanical effect of diffraction. The influence of diffraction and screening effects on the characteristics of electron–atom collisions was investigated. Scattering phase shifts decrease with increase of the de Broglie wave. The electron–atom momentum-transfer cross-section at $\lambda _{B}\to 0$ tends to the data obtained earlier with a neglecting of the diffraction effect.