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Direct Measurement of MHD-induced Fast-ion Redistribution in Space and Energy by NPA Vertical Scanning. Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics NYU ORNL PPPL PSI SNL UC Davis UC Irvine UCLA UCSD U Maryland U New Mexico
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Direct Measurement of MHD-induced Fast-ion Redistribution in Space and Energy by NPA Vertical Scanning Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics NYU ORNL PPPL PSI SNL UC Davis UC Irvine UCLA UCSD U Maryland U New Mexico U Rochester U Washington U Wisconsin Culham Sci Ctr Hiroshima U HIST Kyushu Tokai U Niigata U Tsukuba U U Tokyo JAERI Ioffe Inst TRINITI KBSI KAIST ENEA, Frascati CEA, Cadarache IPP, Jülich IPP, Garching U Quebec S. S. Medley XP707 Review PPPL, February 8, 2007
The Neutral Particle Analyzer (NPA) on NSTX ScansVertically Over a Wide Range of Angles on a Shot-to-Shot Basis The elevation minor radius at the intersection of the NPA sightline with a given neutral beam line depends on the NPA horizontal tangency radius.
TRANSP Anomalous Fast Ion Diffusion (AFID) Can Simultaneously Match Sn(t), Snpa(t) and fnpa(E) • In TRANSP, AFID can be specified in space, time and fast-ion energy. ne(au)
NPA Vertical Scan Can Measure MHD-induced Spatial Redistribution of Energetic Ions Without AFID With AFID •TRANSP simulation (119768M22) of NPA vertical scan without anomalous fast ion diffusion (left) and with core-weighted anomalous fast ion diffusion (right). •At E > E/2, on-axis ions are depleted and redistributed outward by ~ 20 cm.
Target Discharge Characteristics (Part I: MHD Aactivity with f < 200 kHz) •Long pulse H-mode (t ~ 1 s) with A, B, C @ 90 keV. •Stable outer gap ~ 5-10 cm early in discharge and ne(r) ‘flattop’ after t ~ 0.5 s. •Wide range of reproducible *AE and MHD activity with a quiescent period ~ 100 ms. •Strong depletion of the NPA energetic ion spectrum down to E/3.
Target Discharge Characteristics (Part II: MHD Activity with f > 200 kHz) •Long pulse H-mode (t ~ 1 s) with A, B, C @ 90 keV. •Stable outer gap ~ 5-10 cm early in discharge and ne(r) ‘flattop’ after t ~ 0.5 s. •Quiescent phase for f < 200 kHz at t > 0.7 s with continuing activity at f > 200 kHz. •Strong depletion of the NPA energetic ion spectrum down to E/3.
XP Scan Details √ Exploit expanded diagnostic coverage - sFLIP (image capture for full t ~ 1 s discharges) - multi-color USXR (profile inversion for mode location) - faster NPA data acquisition (t ~ 0.1 ms) - ssNPA (simultaneous 4-chord mid-plane profile) √NPA vertical scanning requires removal of the Lithium Pellet Injector