Commissioning and model validation of SVR divertor and validation of pumping design
2024 Research Campaign, Thrust: Shape Rise Divertor
Purpose of Experiment
The Shape and Volume Rise (SVR) project at DIII-D involved the removal of an in-vessel cryopump and modifying the divertor baffling structures with the goal of enabling tokamak plasma equilibrium shapes with larger volume, elongation and triangularity. These shape changes are predicted to enable a significant increase in confined plasma pressure. However, efficient particle removal is required to reach sufficiently low density to access the enhanced confinement regime, at which point the density can be increased dynamically to operate achieve very high confinement operation. It is therefore critical to the success to the SVR experimental campaign, in which there are several weeks’ worth of experiments planned in the next 2 years, that the pumping efficiency of the new divertor installation be tested and explored in this first experiment. The principles used in the design process for the newly installed divertor will be tested against measurements from this experiment, and plasma boundary modeling will be used to help evaluate the effectiveness of the pumping design. A piggyback experiment will also be performed to optimize the 3D error field correction in the new plasma shapes.