Direct Measurement of MHD-induced Fast-ion Redistribution in Space and Energy by NPA Vertical Scanning

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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
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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.
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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)
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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 gt E/2, on-axis ions
are depleted and redistributed outward by 20 cm.
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Target Discharge Characteristics (Part I MHD
Aactivity with f lt 200 kHz)
Long pulse H-mode (t 1 s) with A, B, C _at_ 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.


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Target Discharge Characteristics (Part II MHD
Activity with f gt 200 kHz)
Long pulse H-mode (t 1 s) with A, B, C _at_ 90
keV. Stable outer gap 5-10 cm early in
discharge and ne(r) flattop after t 0.5 s.
Quiescent phase for f lt 200 kHz at t gt 0.7 s
with continuing activity at f gt 200 kHz.
Strong depletion of the NPA energetic ion
spectrum down to E/3.


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XP Scan Details


v 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) v NPA vertical
scanning requires removal of the Lithium Pellet
Injector
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Scope Waveforms 117449
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Scope Waveforms 119768
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Scope Waveforms 119613
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Scope Waveforms 120001
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Scope Waveforms 119992