@article{d212a62186294e66bfd30aebc43abb34,
title = "Role of poloidal E × B drift in divertor heat transport in DIII-D",
abstract = "Simulations for DIII-D high confinement mode plasmas with the multifluid code UEDGE show a strong role of poloidal E × B drifts on divertor heat transport, challenging the paradigm of conduction-limited scrape-off layer (SOL) transport. While simulations with reduced drift magnitude are well aligned with the assumption that electron heat conduction dominates the SOL heat transport, simulations with drifts predict that the poloidal convective E × B heat transport dominates over electron heat conduction in both attached and detached conditions. As poloidal E × B flow propagates across magnetic field lines, poloidal transport with shallow magnetic pitch angles can reach values that are of the same order as would be provided by sonic flows parallel to the field lines. These flows can lead to strong convection-dominated divertor heat transport, increasing the poloidal volume of radiative power front, consistent with previous measurements at DIII-D. Due to these convective flows, the Lengyel integral approach, assuming zero convective fraction, is expected to provide a pessimistic estimate for the radiative capability of impurities in the divertor. For the DIII-D simulations shown here, the Lengyel integral approach underestimates the radiated power by a factor of 6, indicating that, for reliable DIII-D divertor power exhaust predictions, full two-dimensional (2D) calculations, including drifts, would be necessary.",
keywords = "conduction, convection, divertor, drifts, heat transport, radiation",
author = "Jaervinen, {A. E.} and Allen, {S. L.} and Leonard, {A. W.} and McLean, {A. G.} and Moser, {A. L.} and Rognlien, {T. D.} and Samuell, {C. M.}",
note = "Funding Information: This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favouring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Funding Information: information Lawrence Livermore National Laboratory, LDRD 17-ERD-020; U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, DE-AC52-07NA27344; DE-FC02-04ER54698This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, using the DIII-D National Fusion Facility, a DOE Office of Science user facility, under Awards DE-FC02-04ER54698, DE-AC52-07NA27344, and LLNL LDRD project 17-ERD-020. Funding Information: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, using the DIII‐D National Fusion Facility, a DOE Office of Science user facility, under Awards DE‐FC02‐04ER54698, DE‐AC52‐07NA27344, and LLNL LDRD project 17‐ERD‐020. Publisher Copyright: {\textcopyright} 2019 The Authors Contributions to Plasma Physics Published by Wiley-VCH Verlag GmbH & Co. KGaA",
year = "2020",
month = jun,
day = "1",
doi = "10.1002/ctpp.201900111",
language = "English",
volume = "60",
journal = "Contributions to Plasma Physics",
issn = "0863-1042",
publisher = "Wiley-VCH Verlag",
number = "5-6",
}