Design and measurement methods for a lithium vapor box similarity experiment

Jacob A Schwartz; Eric D Emdee; M A Jaworski; R J Goldston

doi:10.1063/1.5039406

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arXiv · 1808.02908

Design and measurement methods for a lithium vapor box similarity experiment

Jacob A Schwartz·Eric D Emdee·M A Jaworski·R J Goldston

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Abstract

The lithium vapor box divertor is a concept for handling the extreme divertor heat fluxes in magnetic fusion devices. In a baffled slot divertor, plasma interacts with a dense cloud of Li vapor which radiates and cools the plasma, leading to recombination and detachment. Before testing on a tokamak the concept should be validated: we plan to study detachment and heat redistribution by a Li vapor cloud in laboratory experiments. Mass changes and temperatures are measured to validate a Direct Simulation Monte Carlo model of neutral Li. The initial experiment involves a 5 cm diameter steel box containing 10 g of Li held at 650 degrees C as vapor flows out a wide nozzle into a similarly-sized box at a lower temperature. Diagnosis is made challenging by the required material compatibility with lithium vapor. Vapor pressure a steep function of temperature, so to validate mass flow models to within 10%, absolute temperature to within 4.5 K is required. The apparatus is designed to be used with an analytical balance to determine mass transport. Details of the apparatus and methods of temperature and mass flow measurements are presented.

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Jacob A Schwartz, Eric D Emdee, M A Jaworski, R J Goldston. 2018-08-08. Design and measurement methods for a lithium vapor box similarity experiment. https://doi.org/10.1063/1.5039406

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