MHD modeling of a DIII-D low-torque QH-mode discharge and comparison to observations
- Tech-X Corp., Boulder, CO (United States)
- General Atomics, San Diego, CA (United States)
- Oak Ridge Associated Universities (ORAU), Oak Ridge, TN (United States)
- Tech-X Corp., Boulder, CO (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Extended-MHD modeling of DIII-D tokamak quiescent H-mode (QH-mode) discharges with nonlinear NIMROD simulations saturates into a turbulent state but does not saturate when the steady-state flow inferred from measurements is not included. This is consistent with the experimental observations of the quiescent regime on DIII-D. The simulation with flow develops into a saturated turbulent state where the nΦ = 1 and 2 toroidal modes become dominant through an inverse cascade. Each mode in the range of nΦ = 1–5 is dominant at a different time. Consistent with experimental observations during QH-mode, the simulated state leads to large particle transport relative to the thermal transport. Analysis shows that the amplitude and phase of the density and temperature perturbations differ resulting in greater fluctuation-induced convective particle transport relative to the convective thermal transport. As a result, comparison to magnetic-coil measurements shows that rotation frequencies differ between the simulation and experiment, which indicates that more sophisticated extended-MHD two-fluid modeling is required.
- Research Organization:
- Tech-X Corp., Boulder, CO (United States); General Atomics, San Diego, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES); USDOE Office of Nuclear Energy (NE)
- Grant/Contract Number:
- FC02-06ER54875; AC02-05CH11231; AC02-06CH11357; FC02-04ER54698; FC02-08ER54972
- OSTI ID:
- 1347994
- Alternate ID(s):
- OSTI ID: 1348026; OSTI ID: 1406354
- Journal Information:
- Physics of Plasmas, Vol. 24, Issue 5; Conference: manuscript associated with invited talk at APS-DPP Annual Meeting, 2016, in San Jose; ISSN 1070-664X
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Physics of increased edge electron temperature and density turbulence during ELM-free QH-mode operation on DIII-D
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journal | May 2018 |
Access and sustainment of naturally ELM-free and small-ELM regimes
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journal | September 2018 |
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