https://doi.org/10.1051/epjconf/201715703052
Time-Dependent Simulations of Fast-Wave Heated High-Non-Inductive-Fraction H-Mode Plasmas in the National Spherical Torus Experiment Upgrade
1 Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543, USA
2 William E. Boeing Department of Aeronautics and Astronautics, University of Washington, Seattle, Washington 98195, USA
* Corresponding author: gtaylor@pppl.gov
Published online: 23 October 2017
30 MHz fast-wave heating may be an effective tool for non-inductively ramping low-current plasmas to a level suitable for initiating up to 12 MW of neutral beam injection on the National Spherical Tokamak Experiment Upgrade (NSTX-U). Previously on NSTX 30 MHz fast wave heating was shown to efficiently and rapidly heat electrons; at the NSTX maximum axial toroidal magnetic field (BT(0)) of 0.55 T, 1.4 MW of 30 MHz heating increased the central electron temperature from 0.2 to 2 keV in 30 ms and generated an H-mode plasma with a non-inductive fraction (fNI) ∼ 0.7 at a plasma current (Ip) of 300 kA. NSTX-U will operate at BT(0) up to 1 T, with up to 4 MW of 30 MHz power (Prf). Predictive TRANSP free boundary transport simulations, using the TORIC full wave spectral code to calculate the fast-wave heating and current drive, have been run for NSTX-U Ip = 300 kA H-mode plasmas. Favorable scaling of fNI with 30 MHz heating power is predicted, with fNI ≥ 1 for Prf ≥ 2 MW.
© The authors, published by EDP Sciences, 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
