Prakash, R., Pütterich, T., Dux, R., Kallenbach, A., Fischer, R., Behringer, K., & ASDEX Upgrade Team(2006). Spectroscopic Divertor Characterization and Impurity Influx Measurements in ASDEX Upgrade Tokamak (IPP 10/31). Garching: Max-Planck-Institut für Plasmaphysik.