XP-746: ELM characterization in NSTX

R. J. MaquedaNova Photonics Inc.

and the NSTX Research Team

’07 Results ReviewJuly 23-24, 2007

PPPL

2

XP-746: ELM characterization in NSTX

• ½ run day on June 5th (17 shots: 124659-124675)

• All 3 ELM Types produced and measuredType I: 124659-124664, 124669Type III: 124665-124668Type V: 124670-124675

• Good diagnostic availability:fast-framing camerasUSXR arrays (JHU)static (ORNL/PPPL) and reciprocating (UCSD) probesreflectometers (UCLA)MIRNOV arrays (PPPL)

XP Summary

XP Goals• Measure and characterize evolution of ELMs observed in NSTX: structure of ELM

perturbed edge, birth of filamentary ELM structures, radial and poloidal/toroidal propagation in SOL, increase of edge turbulence and blobs, and recovery of inter-ELM profiles.

• Obtain profiles for ELM stability evaluation.

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Shot 124675

TYPE I ELMs

Shot 124667TYPE III ELMs

Shot 124664

TYPE V ELMs

Time (s)

Lo

we

r d

ive

rto

r D

(

a.u

.)

GPI viewD2 puff - D filter

Fish-eye viewno filter

Fast-framing cameras show global and local evolution

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ELM filamentation after ELM onset

ELM sequence• Mode growth.

• Birth of ELM filaments.

• Filament detachment (except in Type V ELMs).

• Filament radial and poloidal/toroidal propagation in SOL – eventual interaction with plasma facing components.

• Turbulent filamentation and blobs, L-mode like.

• Recovery of H-mode edge.

GPI viewno puff - D

filter

TYPE I ELM

5

TYPE III ELMShot 124667

tELM ~ 275.02 msrsep (cm)

D e

mis

sio

n (

a.u

.)

rsep (cm)

Lp

ol

(cm

)

I/I

Ku

rto

ssis

tELM + [200,300] stELM + [300,400] stELM + [400,500] stELM + [500,600] stELM + [600,700] s

ELM filamentation followed by L-mode like turbulence and blobs

Fluctuation levels, auto-correlation lengths and kurtossis similar to L-mode

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Summary

XP-746 run time shots and diagnostic availabilty provide excellent

opportunity to meet XP goals

...work in progress...

• Characterization of ELM mode structure, evolution into filaments, and

propagation of filaments in SOL.

• Characterization of ELM filaments and associated transport.

• Characterization of post-ELM turbulence (blobs) and related transport.

• Availability of profile data for stability analysis.