Complete spin polarization of 0.5-to 500-eV electrons elastically scattered by argon atoms: Theoretical consideration

Within the framework of a phenomenological real optical potential, the elastic scattering of 0.5-to 500-eV electrons by argon atoms is studied in view of spin-orbit interaction. The energy dependences of the angular positions of minima in differential cross sections are calculated and compared with those obtained in experiments. The energies and angular positions of four critical points where the cross sections reach their minimal values are determined. It is found that the deepest minimum of three high-angle ones (with angles >90°) is located at (38.25 eV, 140.67°). The energy and angular neighborhoods of these minima where the parameter of spin polarization, the so-called Sherman function, reaches its extreme values (+1 and −1) are determined.