Stanley M. Kaye

1
XP401 H-mode Confinement Scaling
Stanley M. Kaye PPPL, Princeton University NSTX
Results Review 21 September 2004
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Systematic Parameter Scans Performed

• Run as part of NSTX/MAST identity experiment
• LSN w/ PF1b (k2.1)
• Lower k DND not viable due to high PLH threshold
• Ip scan at fixed P, BT (4.5 T)
• 0.6 to 1.2 MA in 4 steps
• Scans at both 2 and 3 NBI sources
• P scans at fixed Ip, BT (4.5 T)
• Full scans at Ip0.8, 1.0 MA
• Used modulated NBI if necessary to establish low
  P H-mode between 1 and 2 steady sources (i.e., 1
  ½ sources)

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Stored Energy Increases Linearly With Plasma
Current

• 2 NBI Sources

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Confinement Trends From Systematic Scans
Established to be Similar to Those at
Conventional Aspect Ratio
Expand database to include other discharges Study
global dependences of global confinement time
(EFIT)
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Thermal Confinement Times Exhibit Similar Scaling
Thermal tE determined by TRANSP
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Strong BT Dependence Observed For Both Global and
Thermal Confinement ? MHD Important?
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Strong BT and Weaker Ip Dependence In Regressions
? Ip0.65 BT0.45 for both if dataset constrained
to BTgt0.31 T
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Global L-mode Scaling Also Exhibits Strong BT
Dependence (all BT)
Database not complete enough for tEth scaling
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Transport Properties of NSTX Plasmas Are Also
Being Studied

• Electrons dominate loss in most H-modes
• cicNCLASS
• ceci in L-mode
• CHERS recalibration continuing

L-mode