ECRH/EBWH SYSTEM FOR NSTX-U
Authors: G. Taylor, R.A. Ellis, R.W. Harvey, J.C. Hosea and A.P. Smirnov
Abstract:
The National Spherical Torus Experiment Upgrade (NSTX-U) will operate at
an axial toroidal field of up to 1 T, about twice the field available on NSTX. A 28 GHz
electron cylotron resonance heating (ECRH) system is currently being planned for
NSTX-U. A 1 MW 28 GHz gyrotron will be employed. Intially the system will use short,
10-50 ms, 1 MW pulses for ECRH-assisted discharge start-up. Later the pulse length will
be extended to 1-5 s to study electron Bernstein wave heating (EBWH) during the plasma
current flat top. A mirror launcher will be used to couple microwave power to the plasma
via O-mode to the slow X-mode to EBW (O-X-B) double mode conversion. This paper
presents a pre-conceptual design for the ECRH/EBWH system proposed for NSTX-U
and includes ray tracing and Fokker-Planck modeling results for 28 GHz ECRH during
plasma start-up and EBW heating and current drive during the plasma current flattop of a
NSTX-U advanced H-mode plasma scenario.
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Submitted to: 17th Workshop on ECE and ECRH, Deurne, Netherlands (May 7-10, 2012)
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Download PPPL-4758 (pdf KB pp)
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