Griener, M., Wolfrum, E., Munos Burgos, J., Schmitz, O., Stroth, U., & ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society (2017). Line ratio spectroscopy on thermal helium provides electron temperature and density information at the plasma edge of ASDEX Upgrade. Talk presented at DPG-Frühjahrstagung der Sektion Materie und Kosmos (SMuK). Bremen. 2017-03-13 - 2017-03-17.