Investigation of core highk fluctuations

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Investigation of core high-k fluctuations
D. Smith, S. Kaye,E. Mazzucato, and H.
Park PPPL W. Lee POSTECH F. Levinton and H.
Yuh Nova Photonics NSTX FY07 Research
Forum 5-7 December, 2006
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Two objectives

• Measure core high-k fluctuations in RS discharge
• Utilize 1MA RS scenario with longer quiescent MHD
  period
• Highly reproducible
• Compare to 1MA monotonic-q/mild RS discharge
• Last produced in FY05 run campaign
• Moderate shot development possible
• Extension of XP610 F. Levinton and XP620 D.
  Smith
• Augment 5.5 kG RS and RS w/ HHFW proposals
• Measure dependence of core high-k fluctuations on
  TF
• TF scan in XP532 S. Kaye revealed ce inversion
  point
• ce increases (falls) inside (outside) r/a 0.5
  as TF increases
• Measure high-k fluctuations inside and outside
  inversion point

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RS discharges of XP620 hadshort periods of
quiescent MHD
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Utilize RS scenario with longer quiescent MHD
RS scenarios developed in XP610 F. Levinton, H.
Yuh
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Investigate ce inversion found in TF scan

• XP532 S. Kaye revealed ce inversion point as TF
  scanned
• Evidence that electron dynamics control TF
  scaling
• Reproduce TF scan and measure high-k fluctuations
  at r/a 0.25, 0.5 and 0.7

ce
S. Kaye, NSTX 2006 Results Review
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Requirements

• Machine 5.5 kG operation, NBI sources A C
• Diagnostics high-k scattering, MSE, CHERS,
  MPTS, magnetics, neutrons, x-ray arrays
• Run time 1.5 days