X-Point Flow Measurements at the L-H Transition in ASDEX Upgrade

The X-point reciprocating Langmuir probe in ASDEX Upgrade has been recently upgraded with a new drive system and higher-bandwidth measurement electronics. The horizontal plunge direction allows the probe to penetrate through both LFS and HFS at the level of the X-point, thus completely covering the divertor entrance. We present first measurements of density, temperature and flow profiles in different L- and H-mode plasmas close to the transition. The flows are generally larger on the HFS, where the plasma is also denser and colder. Significant differences in temperature and flow patterns are observed in different plasma conditions. Ideas for upgrading the probe shaft to perform LFS and HFS measurements simultaneously for the characterization of transients will be presented.