This title appears in the Scientific Report :
2017
Please use the identifier:
http://dx.doi.org/10.1088/1741-4326/aa6451 in citations.
Advances in understanding of high- Z material erosion and re-deposition in low- Z wall environment in DIII-D
Advances in understanding of high- Z material erosion and re-deposition in low- Z wall environment in DIII-D
Dedicated DIII-D experiments coupled with modeling reveal that the net erosion rate of high-Z materials, i.e. Mo and W, is strongly affected by carbon concentration in the plasma and the magnetic pre-sheath properties. Different methods such as electrical biasing and local gas injection have been in...
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Personal Name(s): | Ding, R. (Corresponding author) |
---|---|
Rudakov, D. L. / Stangeby, P. C. / Wampler, W. R. / Abrams, T. / Brezinsek, S. (Corresponding author) / Briesemeister, A. / Bykov, I. / Chan, V. S. / Chrobak, C. P. / Elder, J. D. / Guo, H. Y. / Guterl, J. / Kirschner, A. / Lasnier, C. J. / Leonard, A. W. / Makowski, M. A. / McLean, A. G. / Snyder, P. B. / Thomas, D. M. / Tskhakaya, D. / Unterberg, E. A. / Wang, H. Q. / Watkins, J. G. | |
Contributing Institute: |
Plasmaphysik; IEK-4 |
Published in: | Nuclear fusion, 57 (2017) 5, S. 056016 - |
Imprint: |
Vienna
IAEA
2017
|
DOI: |
10.1088/1741-4326/aa6451 |
Document Type: |
Journal Article |
Research Program: |
Plasma-Wall-Interaction |
Publikationsportal JuSER |
Dedicated DIII-D experiments coupled with modeling reveal that the net erosion rate of high-Z materials, i.e. Mo and W, is strongly affected by carbon concentration in the plasma and the magnetic pre-sheath properties. Different methods such as electrical biasing and local gas injection have been investigated to control high-Z material erosion. The net erosion rate of high-Z materials is significantly reduced due to the high local re-deposition ratio. The ERO modeling shows that the local re-deposition ratio is mainly controlled by the electric field and plasma density within the magnetic pre-sheath. The net erosion can be significantly suppressed by reducing the sheath potential drop. A high carbon impurity concentration in the background plasma is also found to reduce the net erosion rate of high-Z materials. Both DIII-D experiments and modeling show that local 13CH4 injection can create a carbon coating on the metal surface. The profile of 13C deposition provides quantitative information on radial transport due to E × B drift and the cross-field diffusion. The deuterium gas injection upstream of the W sample can reduce W net erosion rate by plasma perturbation. In H-mode plasmas, the measured inter-ELM W erosion rates at different radial locations are well reproduced by ERO modeling taking into account charge-state-resolved carbon ion flux in the background plasma calculated using the OEDGE code. |