, Scrape-Off Layer"): plasma-wall interaction ? E r "´??T Ion orbit losses ? plasma polarization E r Magnetic geometry: X-point Unbalanced vertical charge sep. ? E r Collisional damping: neoclassics ? v ? " K p? ? , ?q?T {eB neutrals ? collisional friction Common assumption of scale separation breaks down at the edge Equilibrium gradient length can reach a few tens of ? i Neoclassical &, Zonal Flows): Large fluctuations at the edge ? large E r ? Unconfined region