Doctoral Dissertations

Orcid ID

https://orcid.org/0000-0002-0961-9139

Date of Award

8-2024

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Energy Science and Engineering

Major Professor

David C. Donovan

Committee Members

Theodore Biewer, Livia Casali, Ezekial Unterberg

Abstract

The economic and engineering success of magnetic confinement fusion reactors significantly depends upon the optimization of plasma facing component (PFC) design. For high-Z PFCs, the critical engineering condition is minimal net erosion (i.e. gross erosion – redeposition). Here, we present a high-Z net erosion model discriminating three primary redeposition mechanisms: prompt (geometric-driven), local (sheath-driven), and far (scrape-off-layer-driven). Using these distinctions, we show modeling for high-Z net erosion in magnetic-confinement fusion over a matrix of key plasma parameters. With Sobol’ methods we assess the sensitivity of each mechanism and show that prompt-vs-local trade-off critically explains underprediction in redeposition losses of up to two orders of magnitude across magnetic-field-to-PFC pitch angles. Finally, we report a “design-of-experiment” study exploring the measurability of prompt vs local distinctions in current experimental facilities. We use a combination of synthetic diagnostics and plasma-parameter optimization to propose an isotopic method of measurement by exploiting robust in situ and ex situ techniques. In principle, this approach provides a ready path forward for improving and validating PFC models needed to target optimal regimes of PFC design in future reactors.

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