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	48: Dependence of momentum transport and intrinsic torque on rho* and beta
Name:	Tuomas Tala Tuomas.Tala@vtt.fi	Affiliation:	VTT Technical Research Centre
Research Area:	Plasma Rotation	Presentation time:	Not requested
Co-Author(s):	W. Solomon, A. Salmi, C. Angioni	ITPA Joint Experiment :	Yes
Description:	This proposal consists of two ITPA experiments TC-15 and TC-17 experiment. TC-15 is about studying parametric dependences of momentum transport coefficients (pinch + diffusion) on several plasma parameters and TC-17 is about determining the intrinsic torque. The objective of this experiment is to study the dependence of the momentum pinch and Prandtl numbers on beta and rho* while a similar, strongly linked proposal by W. Solomon focuses on the intrinsic torque and its dependences on the same parameters rho* and beta.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:
Background:	In recent years, several tokamaks have shown that a significant inward momentum pinch exists. There are a few parameters believed to determine the size of the dimensionless pinch number and the Prandtl number. Experimentally, the pinch number has been found to depend strongly on R/Ln on JET, DIII-D and AUG. On the other hand, no significant collisionality dependence has been found on neither on DIII-D nor on JET (the first part of the TC-15 experiment was carried out on DIII-D and published in PoP in 2010 by W. Solomon et al and IAEA FEC 2012 by T. Tala). While the parametric dependencies (collisionality, R/Ln, q) of the momentum pinch ITG dominated plasmas were included in TC-15 joint experiment, no studies of momentum pinch in high beta plasmas was included and no studies of rho* dependence were done. According to gyro-kinetic simulations, the pinch number depends strongly on beta. At low beta, ITG completely dominates and momentum pinch depends only weakly on beta, but at higher beta, kinetic-ballooning modes become significant and momentum pinch is decreased and eventually becomes an outward convection. Similarly to momentum transport studies, or even more importantly, no rho* scaling experiment to study the dependence of intrinsic torque has been performed. This is definitely needed for any reliable intrinsic torque extrapolation to ITER, and in 2013, this ITPA TC-17 experiment will be pushed in JET to get experimental time in the C32 campaign.
Resource Requirements:	Co- and counter NBI
Diagnostic Requirements:	Full profile diagnostics, especially CER, plus FIDA and main ion CER.
Analysis Requirements:	Standard, well-developed techniques will be used to analyse the NBI modulation and intrinsic torque analysis.
Other Requirements: