TY - GEN
T1 - Overview of activities for the wendelstein 7-X scraper element collaboration
AU - Lumsdaine, A.
AU - Bjorholm, T.
AU - Harris, J.
AU - McGinnis, D.
AU - Lore, J. D.
AU - Boscary, J.
AU - Tretter, J.
AU - Clark, E.
AU - Ekici, K.
AU - Fellinger, J.
AU - Holbe, H.
AU - Neilson, H.
AU - Titus, P.
AU - Wurden, G.
N1 - Publisher Copyright:
© 2015 IEEE.
PY - 2016/5/31
Y1 - 2016/5/31
N2 - The Wendelstein 7-X (W7-X) stellarator is in final stages of commissioning, and will begin operation in the last half of 2015. In this first phase the machine will operate with a limiter, and will be restricted to low power and short pulse. But in 2019, plans are for an actively cooled divertor to be installed, and the machine will operate in steady-state at full power. Recently, plasma simulations have indicated that, in this final operational phase, a bootstrap current may evolve in certain scenarios. This will cause the sensitive ends of the divertor target to be overloaded beyond their qualified limit. A high heat flux scraper element (HHF-SE) has been proposed in order to take up some of the convective flux and reduce the load on the divertor. In order to examine whether the HHF-SE will be able to effectively reduce the plasma flux in the divertor region of concern, and to determine how the pumping effectiveness will be affected by such a component, it is planned to include a test divertor unit scraper element (TDU-SE) in 2017 during an earlier operational phase. Several US fusion energy science laboratories have been involved in the design, analysis (structural and thermal finite element, as well as computational fluid dynamics), plasma simulation, planning, prototyping, and diagnostic development around the scraper element program (both TDU-SE and HHF-SE). This paper presents an overview of all of these activities, and their current status.
AB - The Wendelstein 7-X (W7-X) stellarator is in final stages of commissioning, and will begin operation in the last half of 2015. In this first phase the machine will operate with a limiter, and will be restricted to low power and short pulse. But in 2019, plans are for an actively cooled divertor to be installed, and the machine will operate in steady-state at full power. Recently, plasma simulations have indicated that, in this final operational phase, a bootstrap current may evolve in certain scenarios. This will cause the sensitive ends of the divertor target to be overloaded beyond their qualified limit. A high heat flux scraper element (HHF-SE) has been proposed in order to take up some of the convective flux and reduce the load on the divertor. In order to examine whether the HHF-SE will be able to effectively reduce the plasma flux in the divertor region of concern, and to determine how the pumping effectiveness will be affected by such a component, it is planned to include a test divertor unit scraper element (TDU-SE) in 2017 during an earlier operational phase. Several US fusion energy science laboratories have been involved in the design, analysis (structural and thermal finite element, as well as computational fluid dynamics), plasma simulation, planning, prototyping, and diagnostic development around the scraper element program (both TDU-SE and HHF-SE). This paper presents an overview of all of these activities, and their current status.
KW - Wendelstein 7X
KW - divertor
KW - high heat-flux
KW - modeling and simulation
UR - http://www.scopus.com/inward/record.url?scp=84978842531&partnerID=8YFLogxK
U2 - 10.1109/SOFE.2015.7482427
DO - 10.1109/SOFE.2015.7482427
M3 - Conference contribution
AN - SCOPUS:84978842531
T3 - Proceedings - Symposium on Fusion Engineering
BT - 2015 IEEE 26th Symposium on Fusion Engineering, SOFE 2015
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 26th IEEE Symposium on Fusion Engineering, SOFE 2015
Y2 - 31 May 2015 through 4 June 2015
ER -
