Broadening of divertor heat flux profile with increasing number of ELM filaments in NSTX
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Chinese Academy of Sciences (CAS), Hefei (China). Inst. of Plasma Physics
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Edge localized modes (ELMs) represent a challenge to future fusion devices, owing to cyclical high peak heat fluxes on divertor plasma facing surfaces. One ameliorating factor has been that the heat flux characteristic profile width has been observed to broaden with the size of the ELM, as compared with the inter-ELM heat flux profile. In contrast, the heat flux profile has been observed to narrow during ELMs under certain conditions in NSTX. In this paper, we show that the ELM heat flux profile width increases with the number of filamentary striations observed, i.e. profile narrowing is observed with zero or very few striations. Because NSTX often lies on the long wavelength current-driven mode side of ideal MHD instabilities, few filamentary structures can be expected under many conditions. Additionally, ITER is projected to lie on the current driven low-n stability boundary, and therefore detailed projections of the unstable modes expected in ITER and the heat flux driven in ensuing filamentary structures is needed.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- National Magnetic Confinement Fusion Science Program of China; USDOE Office of Science (SC)
- Grant/Contract Number:
- AC52-07NA27344; AC02-09CH11466; AC05- 00OR22725; 2011GB107001; AC05-00OR22725
- OSTI ID:
- 1305850
- Alternate ID(s):
- OSTI ID: 1265258
- Report Number(s):
- LLNL-JRNL-700288
- Journal Information:
- Nuclear Fusion, Vol. 54, Issue 12; ISSN 0029-5515
- Publisher:
- IOP ScienceCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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