Diagnostic Needs for Divertor and Edge Physics

Abstract

In order to determine the diagnostic needs for divertor and edge physics, it is important to understand the current state of divertor research and the goals driving that work. In future large tokamak reactors, such as that envisioned by ITER-FEAT, the divertor, and edge plasma, must meet several goals and criteria. The divertor must first be able to handle the power that crosses the separatrix into the Scrape-Off-Layer (SOL), by careful design of the target plates and use of plasma radiation to disperse the heat load. The divertor must also sufficiently pump helium that is produced by fusion reactions in order to avoid dilution of the central plasma. The boundary solution must also provide fueling for the main chamber to reach the high density that is required for optimal production of fusion energy. Finally the boundary solution must be designed to contain impurities that are produced at the plasma facing surfaces and prevent them from contaminating the main plasma.