Momentum-Exchange Current Drive, Alpha Channeling, and Rotation (PhD Oral-24)

The electric field associated with a planar electrostatic wave has no average momentum, and thus as the waves damp, the momentum of the plasma has to be conserved. We examine various implications of this momentum conservation. In the planar problem, we show how wave-mediated momentum exchange between nonresonant and resonant particles can drive net currents in spite of the constraint [1]. This momentum-exchange current drive can provide a possible magnetogenesis mechanism in astrophysical settings. Adding spatial wave structure, important for application to steady-state laboratory devices, introduces new momentum terms. We discuss the implications of our results for wave-mediated perpendicular momentum transport in magnetized plasmas with hot ion gradients, drawing analogies with collisional momentum transport in rotating ExB plasmas [2-4]. \\ 1) I.E. Ochs and N.J. Fisch, Physics of Plasmas 27(6), 062109 (2020).\\ 2) E.J. Kolmes, I.E. Ochs, M.E. Mlodik, J.M. Rax, R. Gueroult, and N.J. Fisch, Physics of Plasmas 26(8), 082309 (2020).\\ 3) I. E. Ochs and N. J. Fisch, Physical Review Letters 121, 235002 (2018).\\ 4) I. E. Ochs and N. J. Fisch, Physics of Plasmas 25(12), 122306 (2018).