Fast wave heating in the NSTX-Upgrade device

Journal Article · Tue Jan 01 00:00:00 EST 2013 · AIP Conference Proceedings

OSTI ID:1150380

Bertelli, Nicola ^[1]; Jaeger, E. F. ^[2]; Berry, Lee Alan ^[3]; Bonoli, P. ^[4]; Budny, R. V. ^[1]; Fu, GuoYong ^[1]; Gerhardt, S. ^[1]; Green, David L ^[5]; Harvey, R. W. ^[6]; Hosea, J. ^[1]; Kramer, G. ^[1]; LeBlanc, B ^[1]; Perkins, R. J. ^[1]; Phillips, C. K. ^[1]; Ryan, Philip Michael ^[5]; Taylor, G. ^[1]; Valeo, E. J. ^[1]; Wilson, J. R. ^[1]; Wright, J. ^[4]

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1. Princeton Plasma Physics Laboratory (PPPL)
2. XCEL
3. XCEL Engineering Inc., Oak Ridge
4. Massachusetts Institute of Technology (MIT)
5. ORNL
6. CompX, Del Mar, CA

NSTX-Upgrade will operate with toroidal magnetic fields (B T) up to 1 T, nearly twice the value used in the experiments on NSTX, and the available NBI power will be doubled. The doubling of B T while retaining the 30 MHz RF source frequency has moved the heating regime from the high harmonic fast wave (HHFW) regime used in NSTX to the mid harmonic fast wave (MHFW) regime. By making use of the full wave code AORSA, this work shows that direct ion damping (mainly by thermal ions localized at the 5th harmonic resonance) might be significant in NSTX-Upgrade under TRANSP predicted full performance conditions and the electron and ion absorption is sensitive to the ratio of electron and ion temperature. Launching at high toroidal wave number appears to be one way to significantly reduce the ion damping. By using the extended AORSA code, which includes a detailed description of the scrape-off layer in the field solutions, we found a large electric field amplitude outside of the last closed flux surface as previously seen in NSTX from AORSA simulations (D. L. Green, et al, Phys. Rev. Lett. 107, 145001 (2011)). Preliminary results by introducing a collision damping in the scrape-off layer in the AORSA code to represent a damping process are presented, showing for the first time absorbed power in the scrape-off layer.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1150380
• Journal Information: AIP Conference Proceedings, Vol. 1580
• Country of Publication: United States
• Language: English