On the determination of the poloidal velocity and the shear layer in the SOL of ASDEX Upgrade

A reciprocating probe with six pins was used for localized measurements in the scrape-off layer (SOL) of ASDEX Upgrade (AUG) up to the shear layer (SL) and a few mm inside it. The probe was used to determine the poloidal velocity with three different methods which are critically compared to each other concerning their reliability. Furthermore, we have determined the position of the shear layer.