29th Symposium on Fusion Technology (SOFT 2016)

P2.121 Detailed design and analysis of Wendelstein 7-X scraper element

6 Sep 2016, 14:20

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 121

Poster F. Plasma Facing Components P2 Poster session

Speaker

G Douglas Loesser (Engineering)

Description

G. Douglas Loesser1,Joris Fellinger²2, Hutch Neilson¹1, John Mitchell¹1, Marc Sibilia¹1, Han Zhang¹1, P. Titus¹1, Irving Zatz^1,1,, Arnie Lumsdaine³3, Dean McGinnis³3 1Princeton Plasma Physics Laboratory, James Forestall Campus, Princeton, NJ 08542, USA 2Max-Planck-Institut für Plasmaphysik, Teilinstitut Greifswald, Wendelsteinstraße 1, 17491, Greifswald, Germany 3Oak Ridge National Laboratory, Oak Ridge, TN  37831-6169, USA Wendelstein 7-X stellarator in Greifswald (Germany) successfully started operation in 2015 with short pulse limiter plasmas.  Longer pulsed operation is planned and will require the addition of test divertor units (TDU) with “scraper elements” in front of the divertors leading edges.  The TDU scraper is intended to test whether the scraper will protect the divertor as predicted and to assess the impact on pumping.  These TDU-SE components will be located in two of the ten half modules during W7-X OP1.2 operation.   The passively cooled limiters (TDU-SE) will be instrumented with diagnostics to monitor the impact of the scraper element on the plasma and will be monitored with IR and VIS cameras. The design was developed considering the limited and restrictive installation space available as well as the prescribed plasma facing surface shape and alignment required of the assembly.  This paper describes issues driving design considerations and analysis of the scraper element in Wendelstein 7-X. A complementary paper in this conference entitled “Design and Integration of uncooled scraper element in Wendelstein 7-X” by Joris Fellinger, describes the project goals and integration of these elements into W7-X.