On December 13, 2019 Thierry Kremeyer defended his thesis “Particle Fueling and Exhaust in the Wendelstein 7-X Island Divertor”. This work, funded by the office of Fusion Energy Sciences in the Department of Energy under grant DE-SC0014210 features two accomplishments: one is the development, qualification and successful fielding of the Wisconsin In-Situ Penning (WISP) gauges. Thierry used this specifically developed diagnostic to study helium exhaust in the Island Divertor at W7-X. The second main product of the thesis is the establishment of a single reservoir, global particle balance to study hydrogen fueling and exhaust and calculate the global particle confinement time of hydrogen. With these analysis and diagnostic inventions, Thierry showed for the first time that helium is efficiently collected in the island divertor and that the particle confinement time for hydrogen increases after the transition into detachment. The findings laid ground for detailed follow up studies. They will be conducted by thirty, who stays as a post doctoral researcher in the group and a student focusing on EMC3-EIRENE modeling of neutral particle dynamics in W7-X. Congratulations to Thierry!
— News: 01-07-2020