Study of impurity radiation in ASDEX Upgrade with a spatially scanning spectrometer for the VUV and visible ranges

A combined visible and vacuum ultraviolet (VUV) scanning spectrometer for the investigation of the boundary layer of ASDEX Upgrade has been developed. A rotating mirror is used for poloidal scanning. This mirror can be tilted perpendicular to its rotation axis, enabling observation in the toroidal direction too. The broad spectral range opens a variety of investigation possibilities. Here we present poloidal radiation profiles of different ion species in the VUV. Regions of special interest such as the divertor for target erosion studies and the upper boundary for the estimation of ion penetration depths were investigated with high spatial resolution. Additionally, the application of this instrument is shown for measuring the spatial distributions of impurities injected for radiation cooling.