Simulation of lithium cooling and transport in Magnum-PSI using B2.5-Eunomia coupled codes

In a tokamak a part of the energy is deposited as heat in the region called divertor. Liquid metal divertors seem to be the candidate for next generation fusion experiments due to their numerous cooling channels like ionization and line radiation, and due to the fact that evaporated metals can be easily replenished thanks to high capillarity of metals. One on the main problems of this divertor concept is that if the metal density in the main plasma reaches the Greenwald limit it can cause disruption. For this reason lithium is the best candidate for liquid metal divertors due to its low Z number. Liquid lithium targets concepts can be studied in linear devices such as Magnum-PSI that reproduces divertor high density, low electron temperature conditions. Magnum-PSI plasma dynamics is simulated by B2.5 a uid model code, while neutral dynamics is simulated by Eunomia, a Monte Carlo code. The objective of this project is understanding plasma and neutral dynamics with the purpose of increasing cooling and reducing lithium density upstream. This will be done by studying the coupling of the two codes, upgrading lithium cooling and lithium emission, then internal validation with a liquid lithium target will be performed. Afterwards working range of plasma parameters will be studied calculating heat transport to the target and lithium ux upstream with the aim of understanding the in uence of plasma parameters. Target geometry will be studied by focusing on the vapor box divertor concept and the lithium transport will be optimized. Proposals for optimal liquid metal divertor and vapor box geometry are made according to the results of the simulations.