Effect of the relative shift between the electron density and temperature pedestal position on the pedestal stability in JET-ILW and comparison with JET-C

0498183 - ÚFP 2019 RIV AT eng J - Journal Article
Stefanikova, E. - Frassinetti, L. - Saarelma, S. - Loarte, A. - Nunes, I. - Garzotti, L. - Lomas, P. - Rimini, F. - Drewelow, P. - Kruezi, U. - Lomanowski, B. - De La Luna, E. - Meneses, L. - Peterka, Matěj - Viola, B. - Giroud, C. - Maggi, C. … Total 18 authors
Effect of the relative shift between the electron density and temperature pedestal position on the pedestal stability in JET-ILW and comparison with JET-C.
Nuclear Fusion. Roč. 58, č. 5 (2018), č. článku 056010. ISSN 0029-5515. E-ISSN 1741-4326
EU Projects: European Commission(XE) 633053 - EUROfusion
Institutional support: RVO:61389021
Keywords : pedestal * JET-ILW * JET-C
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 3.516, year: 2018
http://iopscience.iop.org/article/10.1088/1741-4326/aab216/meta

The electron temperature and density pedestals tend to vary in their relative radial positions, as observed in DIII-D (Beurskens et al 2011 Phys. Plasmas 18 056120) and ASDEX Upgrade (Dunne et al 2017 Plasma Phys. Control. Fusion 59 14017). This so-called relative shift has an impact on the pedestal magnetohydrodynamic (MHD) stability and hence on the pedestal height (Osborne et al 2015 Nucl. Fusion 55 063018). The present work studies the effect of the relative shift on pedestal stability of JET ITER-like wall (JET-ILW) baseline low triangularity (δ) unseeded plasmas, and similar JET-C discharges. As shown in this paper, the increase of the pedestal relative shift is correlated with the reduction of the normalized pressure gradient, therefore playing a strong role in pedestal stability. Furthermore, JET-ILW tends to have a larger relative shift compared to JET carbon wall (JET-C), suggesting a possible role of the plasma facing materials in affecting the density profile location.
Permanent Link: http://hdl.handle.net/11104/0290579