Experimental confirmation of efficient island divertor operation and successful neoclassical transport optimization in Wendelstein 7-X
Name
Sunn_Pedersen_2022_Nucl._Fusion_62_042022.pdf
Description
Published version
Size
2.24 MB
Format
Adobe PDF
Checksum (MD5)
2f68590a911adb7d2d8db43937d830c2
Author(s)
Porkolab, Miklos
White, Anne
Date Issued
2022
Journal
Nuclear Fusion
Publisher
IOP Publishing
Citation
Porkolab, Miklos and White, Anne. 2022. "Experimental confirmation of efficient island divertor operation and successful neoclassical transport optimization in Wendelstein 7-X." Nuclear Fusion, 62 (4).
Version
Final published version
Abstract
Abstract
We present recent highlights from the most recent operation phases of Wendelstein 7-X, the most advanced stellarator in the world. Stable detachment with good particle exhaust, low impurity content, and energy confinement times exceeding 100 ms, have been maintained for tens of seconds. Pellet fueling allows for plasma phases with reduced ion-temperature-gradient turbulence, and during such phases, the overall confinement is so good (energy confinement times often exceeding 200 ms) that the attained density and temperature profiles would not have been possible in less optimized devices, since they would have had neoclassical transport losses exceeding the heating applied in W7-X. This provides proof that the reduction of neoclassical transport through magnetic field optimization is successful. W7-X plasmas generally show good impurity screening and high plasma purity, but there is evidence of longer impurity confinement times during turbulence-suppressed phases.
We present recent highlights from the most recent operation phases of Wendelstein 7-X, the most advanced stellarator in the world. Stable detachment with good particle exhaust, low impurity content, and energy confinement times exceeding 100 ms, have been maintained for tens of seconds. Pellet fueling allows for plasma phases with reduced ion-temperature-gradient turbulence, and during such phases, the overall confinement is so good (energy confinement times often exceeding 200 ms) that the attained density and temperature profiles would not have been possible in less optimized devices, since they would have had neoclassical transport losses exceeding the heating applied in W7-X. This provides proof that the reduction of neoclassical transport through magnetic field optimization is successful. W7-X plasmas generally show good impurity screening and high plasma purity, but there is evidence of longer impurity confinement times during turbulence-suppressed phases.
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1088/1741-4326/AC2CF5
