Thermal Modeling for a Lithium Vapor Box Experiment*

The lithium vapor box is a concept under development for a future divertor. It consists of a series of boxes filled with lithium vapor, each heated to a different temperature ranging from 350° C to 650° C. As the plasma enters the coldest box and travels to the hottest box, it interacts with the lithium, ionizes it, then recombines at the bottom of the system. The other, colder boxes are used to keep the lithium from escaping into the main chamber by providing a place for it to condense. Previously, the system was modeled assuming a uniform temperature across the walls of each box. In order to more accurately model the heat flow in the system, the DSMC (Direct Simulation Monte Carlo) code “SPARTA” will be coupled with gray, diffuse, thermal radiation transfer code. Progress on improving models will be reported.