Charge Separation and Electric Field at a Cylindrical Plasma Edge

Comment on “Equilibrium potential well due to finite Larmor radius effects at the tokamak edge” [Phys. Plasmas 24, 081204 (2017)]

“…There are a number of physical situations where plasmas neutrality breaks down through boundary layers which are either free or in contact with a wall. We would like to draw attention that the fundamental physics of the problem of the formation of an electric field at a free plasma edge or at a plasma-wall transition, caused by the difference in gyroradii between electrons and ions in the presence of spatial inhomogeneity, has been studied in more than two dozen publications for close to fifteen years, in planar and cylindrical geometry, by solving both the gyrokinetic equations approximation 2-8 and the full kinetic Vlasov equation [9][10][11][12][13][14][15][16][17][18][19][20][21] for plasmas using Eulerian Vlasov codes. These publications present also the pertinent numerical details for the numerical solution of these equations.…”