Divertor heat flux challenge and mitigation in SPARC
Name
divertor-heat-flux-challenge-and-mitigation-in-sparc.pdf
Description
Published version
Size
1.3 MB
Format
Adobe PDF
Checksum (MD5)
8033a5b4d6309e80cad623c1de84026c
Author(s)
Kuang, AQ
Ballinger, S
Brunner, D
Canik, J
Creely, AJ
Gray, T
Greenwald, M
Hughes, JW
Irby, J
LaBombard, B
Date Issued
2020
Journal
Journal of Plasma Physics
Publisher
Cambridge University Press (CUP)
Version
Final published version
Abstract
© 2020 The Author(s). Owing to its high magnetic field, high power, and compact size, the SPARC experiment will operate with divertor conditions at or above those expected in reactor-class tokamaks. Power exhaust at this scale remains one of the key challenges for practical fusion energy. Based on empirical scalings, the peak unmitigated divertor parallel heat flux is projected to be greater than 10 GW m-2. This is nearly an order of magnitude higher than has been demonstrated to date. Furthermore, the divertor parallel Edge-Localized Mode (ELM) energy fluence projections (∼11-34 MJ m-2) are comparable with those for ITER. However, the relatively short pulse length (∼25 s pulse, with a ∼10 s flat top) provides the opportunity to consider mitigation schemes unsuited to long-pulse devices including ITER and reactors. The baseline scenario for SPARC employs a ∼1 Hz strike point sweep to spread the heat flux over a large divertor target surface area to keep tile surface temperatures within tolerable levels without the use of active divertor cooling systems. In addition, SPARC operation presents a unique opportunity to study divertor heat exhaust mitigation at reactor-level plasma densities and power fluxes. Not only will SPARC test the limits of current experimental scalings and serve for benchmarking theoretical models in reactor regimes, it is also being designed to enable the assessment of long-legged and X-point target advanced divertor magnetic configurations. Experimental results from SPARC will be crucial to reducing risk for a fusion pilot plant divertor design.
MIT Department
Massachusetts Institute of Technology. Plasma Science and Fusion Center
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1017/S0022377820001117
