On the very high energy confinement observed in super H-mode DIII-D experiments

Ding, S.; Garofalo, A. M.; Knolker, M.; Marinoni, A.; McClenaghan, J.; Grierson, B. A.

doi:10.1088/1741-4326/ab66db

On the very high energy confinement observed in super H-mode DIII-D experiments

Journal Article · Tue Jan 21 23:00:00 EST 2020 · Nuclear Fusion

DOI:https://doi.org/10.1088/1741-4326/ab66db· OSTI ID:1594863

^[1]; ^[2]; ^[3]; Marinoni, A. ^[4]; McClenaghan, J. ^[2]; ^[5]

Oak Ridge Associated Univ., Oak Ridge, TN (United States); Chinese Academy of Sciences (CAS), Beijing (China); General Atomics, Energy & Advanced Concepts, DIII-D
General Atomics, San Diego, CA (United States)
Oak Ridge Associated Univ., Oak Ridge, TN (United States)
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Analysis of recent super H-mode experiments on DIII-D shows that high rotation, not high pedestal, plays the essential role in achieving very high confinement H_98y2>1.5. Very high confinement is reached early on in the H-mode phase of these discharges, when the pedestal is still very low, but after the toroidal rotation has already built-up to very high levels in the core. As the discharge evolves, the rotation drops, and so does the energy confinement, despite a sustained very high-pressure pedestal. During this evolution, the confinement quality is linearly correlated with the core toroidal rotation, which varies according to different levels of injected neutral beam torque per particle. Core transport modeling shows that the contribution from rotation in the E×B shear is responsible for confinement quality significantly in excess of standard H-mode (H_98y2~1).

View Accepted Manuscript (DOE)

Research Organization:: General Atomics, San Diego, CA (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)

Grant/Contract Number:: FC02-04ER54698

OSTI ID:: 1594863

Alternate ID(s):: OSTI ID: 23013521

Journal Information:: Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 3 Vol. 60; ISSN 0029-5515

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

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