Edge localized mode characteristics and divertor heat flux during stationary and transient phase for CFETR hybrid scenario
[1];
[3];
[6];
[6];
- Peking Univ., Beijing (China); Oak Ridge Associated Univ., Oak Ridge, TN (United States)
- Southwestern Institute of Physics, Chengdu (China)
- Shenzhen Univ. (China)
- General Atomics, San Diego, CA (United States); Univ. of Science and Technology of China, Hefei (China)
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Chinese Academy of Sciences (CAS), Hefei (China)
- Univ. of California, San Diego, La Jolla, CA (United States)
- Peking Univ., Beijing (China)
- Harbin Institute of Technology (China); Peking Univ., Beijing (China)
The study of edge localized mode (ELM) behavior, stationary heat flux and transient heat flux during the ELM crash phase is performed for a China Fusion Engineering Test Reactor (CFETR) 1 GW hybrid mode operation scenario ($$R$$ = 7.2 m, $${B_{\text{T}}}$$ = 6.5 T, $${I_{\text{p}}}$$ = 13.78 MA). Modeling and simulation start with a scenario obtained by multi-code integrated modeling on the one modeling framework for integrated tasks framework. Linear stability and nonlinear simulations of ELM dynamics are carried out using the BOUT++ six-field reduced magnetohydrodynamic module, which show a much smaller ELM energy loss (ΔELM ~ 0.13%) compared to that of a Type-I ELM. Parametric analysis of the weak linear growth rate and small ELM energy loss characteristics shed light on physics corresponding to a grassy ELM regime for CFETR 1 GW hybrid scenario. The transient heat flux on the divertor target during this small ELM phase is investigated using BOUT++. Here we found that upstream radial transport in the scrape-off-layer (SOL) induced by small ELMs is weak, which keeps it in the drift-dominated region. However, the heat flux width is still broadened to $${\lambda _{\text{q}}}$$ = 4.64 mm by the increase of separatrix temperature during ELM nonlinear evolution. The impact of transient peak heat load and ELM energy fluence on tungsten melting and net erosion rate of divertor target is evaluated for the first-time using physics-based transport that connects the pedestal with the SOL. Energy fluence caused by a single ELM pulse is below the tungsten melting limit, while tungsten erosion would exceed the material requirements. We conclude that external mitigation methods, such as divertor detachment and advanced divertor geometry are likely needed for the steady state operation of CFETR.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA); National Key Research and Development Program of China
- Contributing Organization:
- CFETR Physics Team
- Grant/Contract Number:
- AC52-07NA27344; 2017YFE0300500; 2017YFE0300501; FC02-04ER54698; AC02-05CH11231; No. DE-AC52-07NA27344; No. DE-FC02-04ER54698; No. 2017YFE0300500; No. 2017YFE0300501; No. DE-AC02-05CH11231
- OSTI ID:
- 1883015
- Alternate ID(s):
- OSTI ID: 1756476
- Report Number(s):
- LLNL-JRNL-829024; 1044765; TRN: US2307959
- Journal Information:
- Plasma Physics and Controlled Fusion, Vol. 63, Issue 3; ISSN 0741-3335
- Publisher:
- IOP ScienceCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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