Curious Cross-Field Transport Effects in Multi-ion, Magnetized Plasmas

In contrast to single ion, multiple ion species plasma exhibits new, curious, and large transport effects. On short timescales, where ions exchange momentum, but it takes forty times longer for electrons to participate, the plasma behaves as a most unusual substance, compressible in number density, but incompressible in charge density. In this regime we identified the charge-incompressibility heat pump effect, transferring heat both spatially and between species [1]. Curiously, the direction of impurity transport strongly depends on plasma magnetization, characterized by the ratio of light ion gyrofrequency to the collision frequency between light and heavy ion species [2]. The expulsion of heavy ion impurities from a hotspot occurs sufficiently fast to be observable on MagLIF, so long as plasma becomes sufficiently collisionally magnetized under implosion. Even more curious, multi-ion transport changes its nature in partially ionized plasma, where ions occupy different charge states. We identify a partial-ionization deconfinement effect [3]. The combination of cross-field transport, ionization, and recombination leads to net ion charge moving across magnetic field lines on ion-ion transport timescale as opposed to the electron-ion transport timescale. Cross-field transport effects in multi-ion plasma are important in a number of applications, including nuclear fusion and plasma mass filters.