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Title: Conceptual design of a pre-loaded liquid lithium divertor target for NSTX-U

Journal Article · · Fusion Engineering and Design

In this study, a conceptual design for a pre-filled liquid lithium divertor target for the National Spherical Torus Experiment Upgrade (NSTX-U) is presented. The design is aimed at facilitating experiments with high lithium flux from the plasma facing components (PFCs) in NSTX-U and investigating the potential of capillary based liquid lithium components. In the design, lithium is supplied from a reservoir in the PFC to the plasma facing surface via capillary action in a wicking structure. This working principle is also demonstrated experimentally. Next, a titanium zirconium molybdenum (TZM) prototype design is presented, required to withstand a steady state heat flux peaking at 10 MW m–2 for 5 s and edge localized modes depositing (130 kJ in 2 ms at 10 Hz). The main challenge is to sufficiently reduce the thermal stresses. This is achieved by dividing the surface into brushes and filling the slots in between with liquid lithium. The principle of using this liquid “interlayer” allows for thermal expansion and simultaneously heat conduction, and could be used to significantly reduce the demands to solids in future PFCs. Lithium flow to the surface is analyzed using a novel analytical model, ideally suited for design purposes. Thermal stresses in the PFC are analyzed using the finite element method. As a result, the requirements are met, and thus a prototype will be manufactured for physical testing.

Research Organization:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
Sponsoring Organization:
USDOE
OSTI ID:
1335696
Journal Information:
Fusion Engineering and Design, Vol. 112, Issue C; ISSN 0920-3796
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 11 works
Citation information provided by
Web of Science

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Cited By (5)

Critical Exploration of Liquid Metal Plasma-Facing Components in a Fusion Nuclear Science Facility journal June 2019
Power handling limit of liquid lithium divertor targets journal July 2018
Power handling and vapor shielding of pre-filled lithium divertor targets in Magnum-PSI journal March 2019
Using 3D-printed tungsten to optimize liquid metal divertor targets for flow and thermal stresses journal March 2019
Vapor shielding of liquid lithium divertor target during steady state and transient events journal January 2020

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