On Coulomb scattering in plasma - Quest for high-precision ion beam stopping experiments

Coulomb scattering is the most basic process in fully ionized plasma, yet it is not well understood. It still appears as a miracle that the classical Rutherford cross section applies equally to quantum scattering regimes, though it involves no h-bar. In this talk, I revisit Gordienko’s work [1] that traces this queer fact to a unique property of the 1/r potential. As another consequence, he found that ion stopping in fully ionized plasma involves Bohr’s classical Coulomb logarithm almost exclusively rather than the Bethe-Bloch quantum results. This is in contrast to what is written in most text books. It calls for experimental verification. It requires high-precision stopping experiments using fully-ionized dense plasma targets and fully stripped ion beams having different ion charges and energies. [1] S. Gordienko, D.V. Fisher, J. Meyer-ter-Vehn, Coulomb scattering in plasma revised, arXiv:physics/0305050 (2003).