Enabling access to high performance scenarios using scraper elements in Wendelstein 7-X

The W7-X stellarator has recently completed the first campaign with an island diverted configuration, successfully demonstrating 30 second plasmas with stable power detachment and record triple products for a stellarator. High performance discharges are envisioned for the next campaign, for which simulations predict a net toroidal current of 40kA which evolves over \textasciitilde 100 seconds and shifts the island chain radially inwards. This evolution results in a predicted transient overload along the edges of the divertor. One solution to this overload problem is the installation of ``scraper elements'', which intercept flux to the overloaded components during the toroidal current evolution. To test this concept, two scraper elements were installed during the last campaign. A set of magnetic configurations were developed to mimic the topology of specific points in the current evolution using the W7-X coil set. Experiments showed measured heat flux patterns that agreed well with predictive simulations from field line diffusion and EMC3-EIRENE. The scraper elements reduced the flux to the divertor edges as expected, with a corresponding reduction in the subdivertor pressure. These results demonstrate that scraper elements can enable access to high performance scenarios with significant current.