Design and measurement methods for a lithium vapor box similarity experiment
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.
Keywords
Cite
@article{arxiv.1808.02908,
title = {Design and measurement methods for a lithium vapor box similarity experiment},
author = {Jacob A Schwartz and Eric D Emdee and M A Jaworski and R J Goldston},
journal= {arXiv preprint arXiv:1808.02908},
year = {2018}
}
Comments
5 pages. Contributed paper published as part of the Proceedings of the 22nd Topical Conference on High-Temperature Plasma Diagnostics, San Diego, California, April, 2018