The physics of the scrape-off layer and divertor plasma, which lies on open field line outside the separatrix, is related to but different from the physics of the edge pedestal plasma on closed field lines inside of the separatrix. Measurement and analysis of the particle flows and currents and the electrostatic potential in this region is a major area of current plasma physics research.
W. M. Stacey, “Effect on the Divertor and Scrape-Off Layer Plasma Properties of the Distribution of Power and Particle Influxes From the Core”. Physics of Plasmas 16, 032506 (2009).
W. M. Stacey, “An Investigation of Some Effects of Drifts and Magnetic Field Direction in the Scrape-Off Layer and Divertor of Tokamak Plasmas”. Physics of Plasmas 16, 042502 (2009).