TY - JOUR
T1 - Preparation of erosion and deposition investigations on plasma facing components in Wendelstein 7-X
AU - Dhard, C. P.
AU - Balden, M.
AU - Braeuer, T.
AU - Brezinsek, S.
AU - Coenen, J. W.
AU - Dudek, A.
AU - Ehrke, G.
AU - Hathiramani, D.
AU - Klose, S.
AU - König, R.
AU - Laux, M.
AU - Linsmeier, Ch
AU - Manhard, A.
AU - Masuzaki, S.
AU - Mayer, M.
AU - Motojima, G.
AU - Naujoks, D.
AU - Neu, R.
AU - Neubauer, O.
AU - Rack, M.
AU - Ruset, C.
AU - Schwarz-Selinger, T.
AU - Pedersen, T. Sunn
AU - Tokitani, M.
AU - Unterberg, B.
AU - Yajima, M.
N1 - Publisher Copyright:
© 2017 Max-Planck-Institut für Plasmaphysik.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - In the Wendelstein 7-X stellarator with its twisted magnetic geometry the investigation of plasma wall interaction processes in 3D plasma configurations is an important research subject. For the upcoming operation phase i.e. OP1.2, three different types of material probes have been installed within the plasma vessel for the erosion/deposition investigations in selected areas with largely different expected heat load levels, namely, ≤10 MW m-2 at the test divertor units (TDU), ≤500 kW m-2 at the baffles, heat shields and toroidal closures and ≤100 kW m-2 at the stainless steel wall panels. These include 18 exchangeable target elements at TDU, about 30 000 screw heads at graphite tiles and 44 wafer probes on wall panels, coated with marker layers. The layer thicknesses, surface morphologies and the impurity contents were pre-characterized by different techniques and subjected to various qualification tests. The positions of these probes were fixed based on the strike line locations on the divertor predicted by field line diffusion and EMC3/EIRENE modeling calculations for the OP1.2 plasma configurations and availability of locations on panels in direct view of the plasma. After the first half of the operation phase i.e. OP1.2a the probes will be removed to determine the erosion/deposition pattern by post-mortem analysis and replaced by a new set for the second half of the operation phase, OP1.2b.
AB - In the Wendelstein 7-X stellarator with its twisted magnetic geometry the investigation of plasma wall interaction processes in 3D plasma configurations is an important research subject. For the upcoming operation phase i.e. OP1.2, three different types of material probes have been installed within the plasma vessel for the erosion/deposition investigations in selected areas with largely different expected heat load levels, namely, ≤10 MW m-2 at the test divertor units (TDU), ≤500 kW m-2 at the baffles, heat shields and toroidal closures and ≤100 kW m-2 at the stainless steel wall panels. These include 18 exchangeable target elements at TDU, about 30 000 screw heads at graphite tiles and 44 wafer probes on wall panels, coated with marker layers. The layer thicknesses, surface morphologies and the impurity contents were pre-characterized by different techniques and subjected to various qualification tests. The positions of these probes were fixed based on the strike line locations on the divertor predicted by field line diffusion and EMC3/EIRENE modeling calculations for the OP1.2 plasma configurations and availability of locations on panels in direct view of the plasma. After the first half of the operation phase i.e. OP1.2a the probes will be removed to determine the erosion/deposition pattern by post-mortem analysis and replaced by a new set for the second half of the operation phase, OP1.2b.
KW - Wendelstein 7-X
KW - erosion and deposition
KW - plasma facing components
KW - plasma wall interaction
UR - http://www.scopus.com/inward/record.url?scp=85030857852&partnerID=8YFLogxK
U2 - 10.1088/1402-4896/aa86fb
DO - 10.1088/1402-4896/aa86fb
M3 - Conference article
AN - SCOPUS:85030857852
SN - 0281-1847
VL - 2017
JO - Physica Scripta
JF - Physica Scripta
IS - T170
M1 - 014010
T2 - 16th International Conference on Plasma-Facing Materials and Components for Fusion Applications, PFMC 2017
Y2 - 16 May 2017 through 19 May 2017
ER -