Physics design of a 28 GHz electron heating system for the National Spherical Torus experiment upgrade

Journal Article · Wed Feb 12 00:00:00 EST 2014 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4864606· OSTI ID:22263906

Taylor, G.; Bertelli, N.; Ellis, R. A.; Gerhardt, S. P.; Hosea, J. C.; Poli, F. ^[1]; Harvey, R. W. ^[2]; Raman, R. ^[3]; Smirnov, A. P. ^[4]

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1. Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
2. CompX, Del Mar, California 92014 (United States)
3. University of Washington, Seattle, Washington 98195 (United States)
4. M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

A megawatt-level, 28 GHz electron heating system is being designed to support non-inductive (NI) plasma current (I{sub p}) start-up and local heating and current drive (CD) in H-mode discharges in the National Spherical Torus Experiment Upgrade (NSTX-U). The development of fully NI I{sub p} start-up and ramp-up is an important goal of the NSTXU research program. 28 GHz electron cyclotron (EC) heating is predicted to rapidly increase the central electron temperature (T{sub e}(0)) of low density NI plasmas generated by Coaxial Helicity Injection (CHI). The increased T{sub e}(0) will significantly reduce the I{sub p} decay rate of CHI plasmas, allowing the coupling of fast wave heating and neutral beam injection. Also 28 GHz electron Bernstein wave (EBW) heating and CD can be used during the I{sub p} flat top in NSTX-U discharges when the plasma is overdense. Ray tracing and Fokker-Planck numerical simulation codes have been used to model EC and EBW heating and CD in NSTX-U. This paper presents a pre-conceptual design for the 28 GHz heating system and some of the results from the numerical simulations.

• OSTI ID: 22263906
• Journal Information: AIP Conference Proceedings, Vol. 1580, Issue 1; Conference: 20. topical conference on radiofrequency power in plasmas, Sorrento (Italy), 25-28 Jun 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BERNSTEIN MODE
COMPUTERIZED SIMULATION
ELECTRIC CURRENTS
ELECTRON TEMPERATURE
ELECTRONS
FOKKER-PLANCK EQUATION
GHZ RANGE
HEATING SYSTEMS
H-MODE PLASMA CONFINEMENT
NSTX DEVICE
PLASMA WAVES