High-Z plasma facing components redeposit within the sheath through a combination of two distinct mechanisms: prompt (or geometric-driven) and local (or sheath-driven) redeposition. Experimental efforts are needed to determine the leading-order parameters influencing prompt-vs-local trade-off, which sets the fraction of material entering the scrape-off layer. In preparation for such experiments, leading-order parameters are isolated within the PYEAD-RustBCA-GITR coupled net erosion code using Sobol' sensitivity analysis. Then, experiments resolving prompt-vs-local trade-off under variation of these leading-order parameters are proposed using an isotopic coupon design with multifaceted diagnostic coverage. The measurability of these experiments is evaluated using synthetic diagnostics.
This paper investigates the redeposition of high-Z materials in tokamaks, which is crucial for understanding plasma-material interactions. The study aims to determine the leading factors that influence the trade-off between prompt and local redeposition, which affects the amount of material entering the scrape-off layer. The researchers propose experiments to resolve this trade-off and evaluate the measurability of these experiments using synthetic diagnostics.