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(Mention how triangularity affects the plasma and mention negative triangularity.) |
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and similar for δ<sub>lower</sub>. | and similar for δ<sub>lower</sub>. | ||
The overall triangularity is defined as the mean of δ<sub>upper</sub> and δ<sub>lower</sub>. | The overall triangularity is defined as the mean of δ<sub>upper</sub> and δ<sub>lower</sub>. | ||
Triangularity, especially the triangularity opposite the dominant X-point (so upper triangularity for a lower null plasma), influences the stability and character of the [[pedestal]] and [[Edge Localized Modes|ELMs]].<ref>[[doi:10.1088/0741-3335/42/5A/319|T.H. Osborne, et al., Plasma Phys. Control. Fusion '''42''' (2000) A175]]</ref> | |||
Some devices (TCV and DIII-D) can form plasma cross sections with negative triangularity (the X-points are pushed to larger <math>R</math> than the center of the plasma), which makes H-mode difficult or impossible to access but improves performance of the L-mode.<ref>[[doi:10.1088/1741-4326/abdb95|W. Han, et al., Nucl. Fusion '''61''' (2021) 034003]]</ref> | |||
== See also == | == See also == |
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