High-Resolution Measurements in the EUV on NSTX

High-Resolution Measurements in the EUV on NSTX

Manfred Bitter PPPLLane Roquemore PPPLJaan Lepson UC BerkeleyMing-Feng Gu Stanford UniversitySteve Kahn Stanford University

Manfred Bitter PPPLLane Roquemore PPPLJaan Lepson UC BerkeleyMing-Feng Gu Stanford UniversitySteve Kahn Stanford University

Peter BeiersdorferLLNL

Peter BeiersdorferLLNL

DPP- Oct 25, 2005

Stellar plasma emission spectra

Stellar Flare Plasma Project:We installed a new grating spectrometer on NSTX

Spectral image of CCD camera from new grating spectrometer

Spectral lineout shows the intrinsic impurities

What about nitrogen?

Nitrogen is hardly ever seen!

Some shots have nitrogen

July 14, 2005Nitrogen seen in shots117087, 117113

August 17, 2005Nitrogen seen in shot117786 (strong He puff, LPI)

August 23, 2005Nitrogen seen in all RF shots

August 23 2005 HHFW CD shots had most diverse impurities

August 23 2005 HHFW CD shots had most diverse impurities

A detailed analysis of the "iron" data shows that some of the emission is from nickel

NSTX measurements agree very well with data from stellar coronae

NSTX

PrincetonTokamak

difference= opacity/

NBI-heated discharges produce novel line ratios – evidence for charge exchange?

Strongdecrease

Increase

Such small lineratios are notpredicted by anyknown theory!

Non-intrinsic impurities: Argon injection

Subsequent argoninjection runswere essentiallyinvisibleDensity sensitve

lines

Calibration of density-sensitive line ratios

Tokamak

Outlook