SUMMARY

As part of the ARIES magnetic confinement fusion power plant study, a modular, helium-cooled, jet-impingement, finger-type divertor design that can accommodate an incident heat flux of 10 MW/m^2 has been proposed. However, to date, predictions of the thermal performance of this design are based on numerical and analytical studies. Therefore, in order to validate these predictions, an experimental study using air under dynamically similar conditions in a test section that closely resembles the actual design is proposed. The results of the experiments will be used to validate numerical simulations performed using a commercial computational fluid dynamics software package. The numerical model, once validated by the experimental results, will be employed to predict the performance of the finger-type divertor design under operating conditions beyond those easily achievable in the laboratory. Potential improvements in the thermal performance to be attained by adding arrays of cooling fins of varying geometries and configurations will also be studied using the validated numerical model. The experimental Nusselt number data for air will be translated to prototypical conditions with helium to determine whether the proposed design is practical for future fusion power plants by examining the relationships between coolant mass flow rate, pressure drop across the divertor, the maximum incident heat flux that can be accommodated by the divertor, and the temperature limits imposed by the materials comprising the divertor. The results of this study will provide designers of helium-cooled jet impingement type plasma-facing components in magnetic fusion energy reactors with the necessary experimentally-validated tools to optimize their design and operational parameters within the limits imposed by material properties.