Creation and sustainment of wide pedestal quiescent H-mode with zero net neutral beam torque
Name
20ja117_full.pdf
Size
2.28 MB
Format
Adobe PDF
Checksum (MD5)
f9b996a80f31424d4fb5a022fc861858
Author(s)
Burrell, K.H.
Chen, Xi
Chrystal, C.
Ernst, Darin R.
Grierson, B.A.
Haskey, S.R.
Osborne, T.H.
Paz-Soldan, C.
Wilks, Theresa M.
Date Issued
February 2020
Journal
Nuclear Fusion
Publisher
IOP
Abstract
Recent experiments on DIII-D have shown it is possible to create and sustain wide pedestal quiescent H-mode (QH-mode) plasmas with zero net torque from neutral beam injection (NBI) for the full discharge duration. Wide pedestal QH-mode has many of the features of the previously investigated QH-mode while having the advantage of increased edge pedestal pressure and excellent energy confinement time. Both QH-mode variants operate without edge localized modes. Accordingly, these new discharges demonstrate that significant input torque is not essential to the exploitation of wide pedestal QH-mode in future devices that are expected to have small or non-existent NBI torque. Developing operating conditions that allowed net zero torque access to wide pedestal QH-mode required implementing several techniques to avoid locked modes including minimizing intrinsic error fields, avoiding large sawteeth, and driving toroidal rotation via neoclassical toroidal viscosity.
Description
Submitted for publication in Nuclear Fusion
MIT Department
Massachusetts Institute of Technology. Plasma Science and Fusion Center
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1088/1741-4326/ab940d
