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	46: Does Added Baffling From Re-Configured Tiles on the Lower Divertor Shelf Facilitate Detachment?
Name:	Thomas Petrie petrie@fusion.gat.com	Affiliation:	General Atomics
Research Area:	Divertor & SOL Physics	Presentation time:	Not requested
Co-Author(s):	M.A. Mahdavi	ITPA Joint Experiment :	No
Description:	A toroidally symmetric row of graphite tiles on the low field side of the lower divertor shelf will be installed for the 2013 campaign. The purpose of this reconfiguration is to aid in trapping neutral particles at high values of the outer separatrix strike point, thereby facilitating detachment and low peak heat flux. For a fixed value of the outer strike point, i.e., Rosp = 1.71 m, we will compare existing data from the 2012 campaign (open configuration) with data from the upcoming 2013 campaign (closed configuration). Three separate densities will be directly compared: ne = 3.2-, 4.2-, and 5.2s10^19 m^-3.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	Shots 149609-611 serve as the model shots for comparison. These shots represent the open configuration. These are very high X-point (75 cm off the lower divertor floor), a = 51 cm, Pinj = 5 MW, and Rosp = 1.71 m. We will re-run these shots at the three densities listed above. Based on our SOLPS modeling, we fully expect to see a partially-detached outer leg in the new (closed) configuration at lower density than we found in the model shots.
Background:	We expect the added baffling at the edge of the shelf to greatly facilitate detachment, compared with the present open configuration. We base this prediction on SOLPS modelling and the experimental results from open vs closed divertor plasma behavior studied in the 2012 campaign. This experiment will help QUANTIFY the advantages of baffling in future divertor design relying on large Rosp values.
Resource Requirements:	Machine time 0.25 day (4-5 good shots), ion gradB drift direction is downward, 5 co-beams.
Diagnostic Requirements:	Core Thomson scattering, CER, divertor fixed Langmuir probes on the shelf, lower divertor IR camera, visible tangential TV in lower divertor, and bolometer.
Analysis Requirements:	SOLPS
Other Requirements:	--