Atomic Physics in ITER - The Foundation for the Next Step to Fusion Power

ITER represents the next step towards practical magnetic confinement fusion power. Its primary physics objective is to study plasmas in which the fusion power exceeds the external heating power by a factor of 5 to 10; its technological objectives include the use of superconducting magnets and remote maintenance. We will describe the ITER experiment and then detail the fundamental roles that will be played by atomic physics processes in facilitating the achievement of ITER's objectives. First, atoms and molecules generated by the interaction of the ITER plasma with surrounding material surfaces will impact and, in some respects, dominate the particle, momentum, and energy balances in both the adjacent and confined, core plasmas. Second, impurity radiation in the edge plasma, either from intrinsic or extrinsic species, will ensure that heat coming out from the core is spread more uniformly over the surrounding material surfaces than it would otherwise. Third, many of the diagnostics used to monitor the dense (ne ∼ 1020 m-3), hot (∼ 1 x 108 K) core plasma leverage off of atomic physics effects