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	71: 4. ELM Characterization to Validate BOUT++ ELM Simulations
Name:	Max Fenstermacher fenstermacher@fusion.gat.com	Affiliation:	Lawrence Livermore National Laboratory
Research Area:	Pedestal Structure	Presentation time:	Not requested
Co-Author(s):	S.L. Allen, C.J. Lasnier, I. Joseph, X.Q. Xu	ITPA Joint Experiment :	No
Description:	The goal of this experiment is to obtain a complete set of high temporal resolution data during moderate size Type-I ELMs to be used for validation of BOUT++ non-linear simulations of DIII-D ELMs at experimental conditions. The development of BOUT++ models that can simulate Type-I ELMs at realistic low experimental H-mode collisionalities is part of an internall funded project at LLNL.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	Use standard ELMing H-mode in LSN plasma shape optimized for fast diagnostic characterization of ELM transient behavior. Likely will need to use high triangularity so that OSP is within view of vertical viewing fast IRTV. Adjust power to achieve moderate frequency (~20 Hz) and moderate size (delta_W_ped/W_ped <~ 10%) Type-I ELMs that are optimized of BOUT++ simulation. Obtain simultaneous fast measurements of all possible pedestal, SOL and divertor transients during ELM events, eg. fast heat flux at both strike-points, fast radiated power (DISSRAD), fast magnetics, fast edge CER, fast target tile currents (if possible) etc.
Background:	Initial detailed fast ELM characterization experiments done previously (summarized in PPCF, 45, (2003), pp.1597-1626) showed many features of the perturbation of the pedestal, SOL and divertor during Type-I ELM events. many diagnostic measurements that can contribute to detailed non-linear modeling of ELM evolution have been improved since then, eg. new high resolution Thomson, high temporal resolution CER, edge current profile measurements with LiBeam and edge MSE (co plus counter NBI) etc. Also there has been substantial development of the BOUT++ non-linear ELM simulation capability for cases at realistic, low collisionality experimental pedestal conditions. A new complete ELM characterization dataset would contribute significantly to validation of these new BOUT++ simulation capabilities.
Resource Requirements:	Standard ELMing H-mode, LSN (probably moderately high triangularity, shape optimized for fast pedestal, SOLand divertor measurements, co and counter NBI to optimized edge MSE bootstrap current measurement, all fast edge, SOL and divertor diagnostics. This could be done in a half day experiment.
Diagnostic Requirements:	All fast edge, SOL and divertor diagnostics including both fast vertically viewing IRTV and periscope IR
Analysis Requirements:	Profile fitting, kinetic EFITS, pedestal Er and bootstrap current analysis all fed into BOUT++ simulations of individual ELM events. Detailed comparison of BOUT++ results (synthetic diagnostic development) with fast measurements.
Other Requirements:	--