Local temperature effects in the helical scrape-off layer of startup plasmas at Wendelstein 7-X due to N seeding

N seeding discharges have been performed at Wendelstein 7-X during its startup limiter campaign. In this study, the cooling effects on the local electron temperature Te measured by three diagnostic systems are discussed, which have a defined alignment in the helical SOL topology during the W7-X limiter phase. Radial Te profiles obtained from a thermal helium beam and Te measurements from a reciprocating Langmuir probe system, both located inside the same flux tube as the N injection system, are compared to Te from Langmuir probes installed on a limiter tile, which is not directly connected magnetically to the injection flux channel. This setup enables to study the N cooling effect in the flux tube geometry as an important test which impacts the 3-D topology in a low shear stellarator and the edge cooling symmetry. A clear reduction of Te in the entire SOL has been measured as a reaction to the N seeding and the relative variation in the temperature, however, depends on the actual placing of the diagnostic in the flux tube geometry and on the distances from the N injection point. A direct comparison of the measurements to EMC3-EIRENE modeling will be presented.