Kinetic neoclassical transport in the H-mode pedestal
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- General Atomics, San Diego, CA (United States)
Multi-species kinetic neoclassical transport through the QH-mode pedestal and scrapeoff layer on DIII-D is calculated using XGC0, a 5D full-f particle-in-cell drift-kinetic solver with self-consistent neutral recycling and sheath potentials. We achieved quantitative agreement between the fluxdriven simulation and the experimental electron density, impurity density and orthogonal measurements of impurity temperature and flow profiles by adding random-walk particle diffusion to the guiding-center drift motion. Furthermore, we computed the radial electric field (Er) that maintains ambipolar transport across flux surfaces and to the wall self-consistently on closed and open magnetic field lines, and is in excellent agreement with experiment. The Er inside the separatrix is the unique solution that balances the outward flux of thermal tail deuterium ions against the outward neoclassical electron flux and inward pinch of impurity and colder deuterium ions. Particle transport in the pedestal is primarily due to anomalous transport, while the ion heat and momentum transport is primarily due to the neoclassical transport. The full-f treatment quantifies the non-Maxwellian energy distributions that describe a number of experimental observations in low-collisionallity pedestals on DIII-D, including intrinsic co-Ip parallel flows in the pedestal, ion temperature anisotropy and large impurity temperatures in the scrape-off layer.
- Research Organization:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Sponsoring Organization:
- USDOE Office of Nuclear Energy (NE)
- Grant/Contract Number:
- FC02-04ER54698; AC02-09CH11466; FG02-95ER54309; AC02-05CH11231
- OSTI ID:
- 1345495
- Journal Information:
- Physics of Plasmas, Vol. 21, Issue 7; ISSN 1070-664X
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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