Influence of the dynamic plasma screening on the Ramsauer phenomena for the polarization collision in thermal plasmas

The dynamic plasma screening effects on the Ramsauer phenomena for the electron-atom polarization collision are investigated in dense plasmas. The phase theory and the effective Buckingham potential with the dynamic Debye length are employed to obtain the phase shift and total collision cross section as functions of the collision energy, and Debye length, polarizability, scattering length, and thermal energy. The result shows that the energy for the Ramsauer minimum increases with an increase of the thermal energy. It is also found that the dynamic plasma screening effect suppresses the total polarization cross section below the Ramsauer energy. However, it is found that the dynamic plasma screening effect enhances the total polarization cross section above the Ramsauer energy. The screening effect on the Ramsauer energy is also discussed. (C) 2012 American Institute of Physics. [http://dx.doi.org.access.hanyang.ac.kr/10.1063/1.4707400