ELM induced tungsten melting and its impact on tokamak operation

0433538 - ÚFP 2015 RIV JP eng A - Abstract
Coenen, J.W. - Arnoux, G. - Bazylev, B. - Matthews, G. F. - Jachmich, S. - Balboa, I. - Clever, M. - Dejarnac, Renaud - Coffey, I. - Corre, Y. - Devaux, S. - Frassinetti, L. - Gauthier, E. - Horáček, Jan - Knaup, M. - Komm, Michael - Krieger, K. - Marsen, S. - Meigs, A. - Mertens, Ph. - Pitts, R.A. - Puetterich, T. - Rack, M. - Stamp, M. - Sergienko, G. - Tamain, P. - Thompson, V. … Total 28 authors
ELM induced tungsten melting and its impact on tokamak operation.
21st International Conference on Plasma Surface Interactions 2014. Toki City: National Institute for Fusion Science, 2014. s. 1-93.
[International Conference on Plasma Surface Interactions 2014/21./. 26.05.2014-30.05.2014, Kanazawa]
Institutional support: RVO:61389021
Keywords : Heat loads * misalignment * JET * tungsten * melting
Subject RIV: BL - Plasma and Gas Discharge Physics
http://psi2014.nifs.ac.jp/talks.html

In JET-ILW dedicated melt exposures were performed using a sequence of H-Mode JET pulses with regular type I ELMs.In order to assess the risk of starting ITER operations with a full W divertor,one of the task was to measure the consequences of W transients melting due to ELMs.By moving the outer strike point (OSP) onto a dedicated leading edge the base temperature was raised within 1s to allow transient ELM-driven melting during the subsequent 0.5 s. Almost 6mm3 of W was moved by 150 ELMs within 5 subsequent discharges. Significant material losses in terms of ejections into the plasma were not observed. There is indirect evidence that some small droplets were ejected.The impact on the main plasma parameters is minor and no disruptions occurred.The W-melt gradually moved along the lamella edge towards the high field side, driven by jxB forces.The evaporation rate determined is 100 times less than expected from steady state melting and thus only consistent with transient melting
Permanent Link: http://hdl.handle.net/11104/0237735