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	327: rho* scaling of intrinsic torque between DIII-D and JET
Name:	Wayne Solomon solomon@fusion.gat.com	Affiliation:	General Atomics
Research Area:	Plasma Rotation	Presentation time:	Not requested
Co-Author(s):	T. Tala	ITPA Joint Experiment :	Yes
Description:	Test the rho* scaling of the intrinsic torque by comparing dimensionlessly similar discharges between DIII-D and JET.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	Produce matched pairs of DIII-D/JET discharges (fixed q, betaN, nu*) with different rho* (perhaps using recent hybrid shots by Politzer to look at rho* scaling of hybrid confinement). Make NBI torque perturbations (steps and low frequency modulation) to infer intrinsic torque as described eg in Solomon et al PoP 2010, and combine with modulation techniques to simultaneously measure chi_phi and vpinch. Since edge intrinsic torque is believed to depend on pedestal gradients and edge temperature, perform combinations of betaN and Ip scans around the identity match as indirect ways of varying these.
Background:	Measurements on DIII-D have shown a clear dependence of the edge intrinsic torque on both the pedestal pressure and edge temperature, and an expression predicting the intrinsic drive has been derived. However, it still remains unclear how this torque scales to ITER with rho*. Theoretical arguments may suggest as unfavorable as rho*^3, while other simulations seems to indicate only a weak rho* dependence. By combining the rho* scans from DIII-D and JET (starting from the matched pair), a wide enough scan is produced so that ITER extrapolation becomes reliable. This experiment has been prepared and approved on JET.
Resource Requirements:	1 day experiment, modulated co and counter NBI
Diagnostic Requirements:	Full profile diagnostics, especially CER, plus FIDA and main ion CER.
Analysis Requirements:	TRANSP, intrinsic torque + modulated transport analysis
Other Requirements: