Auburn University CTH and W7-X Research Progress and Plans

The Compact Toroidal Hybrid (CTH) is a torsatron/tokamak hybrid. The main goals of the CTH experiment currently are to study a variety of fusion related issues that bridge the gap from axisymmetric tokamaks to fully three dimensional stellarators. Recent non-resonant divertor experiments have measured for the first time the behavior of stike lines with large equilibrium changes due to varying Ohmic plasma currents. These strike line locations are observed to be resilient in location as the equilibrium varies. Runaway electron studies have developed a technique to study a well confined runaway beam on magnetic surfaces. Recent results will be overviewed, including the deployment of a new gamma ray imager, and their relevance to tokamaks will be discussed. Ongoing diagnostic development for the experiment includes development of new Hall probe array measurements in aid in vertical stability experiments, and new spectroscopic studies of W and other high Z materials. Auburn research on W7-X will be summarized including the study of drift effects on divertor operation, plans for plasma edge Tungsten optical measurements and core Tungsten transport experiments using x-ray spectroscopy. Discussion of new research directions on both CTH and W7-X will be presented.