DIII-D RESEARCH OPPORTUNITIES FORUM FOR THE 2013 EXPERIMENTAL CAMPAIGN Review | Direct submission with log-in | Request submission without log-in
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Title	225: Study of atomic and molecular processes in deep detachment conditions
Name:	Adam McLean mclean@fusion.gat.com	Affiliation:	Lawrence Livermore National Laboratory
Research Area:	Divertor & SOL Physics	Presentation time:	Requested
Co-Author(s):	M. Groth, T. Carlstrom, B. Bray, S. Allen, V. Soukhanovskii	ITPA Joint Experiment :	No
Description:	Low temperature detached operation in the ITER divertor will lead to generation of recombination, and atomic and molecular interactions which will dominate plasma-surface interactions near the targets. DIII-D with its combination of the upgraded DTS and spectroscopic diagnostics is uniquely capable to study the existence of these processes and aide in validation of state-of-the-art boundary simulation codes.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	Density scan in low power L-mode and H-mode plasmas using a SAPP plasma configuration. Increase density in step-wise fashion to determine maximum density operating point with steady flattop. Repeat discharge for spectroscopy, imaging, and improved sample statistics.
Background:	Refurbishment of the DTS system has led to unprecedented capability for accurate measurement of low plasma temperatures, significantly below 1 eV. This capability will extend the uniqueness of the DIII-D DTS system to study ion recombination, and molecular dissociation, excitation, and interaction in low temperature conditions, and help elucidate their role in the detachment process. These are described in detail for Hydrogen and the CxHy,x=1-3 families at www.eirene.de/html/a_m_data.html with many processes including data in the 0.1-10 eV range, and have been incorporated into the Monte Carlo neutral modeling code EIRENE, but to date has very little in-situ data to compare/validate the models to with reliable local temperature measurements.
Resource Requirements:	LSN with OSP near the DiMES radius with sweeps for outer leg characterization. Gas puffing for high density operation near maximum capable n/nGW before MARFE formation.
Diagnostic Requirements:	Extended/enhanced DTS, high resolution MDS, NIR spectroscopy, filtered DiMES TV, filtered Tan TV, floor LPs, compact spectrometers
Analysis Requirements:	Plasma conditions from DTS and LPs, 2-D reconstructions of D and C emission profiles for UEDGE/OEDGE simulation with EIRENE neutral modeling.
Other Requirements:	--