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	7: Investigate angular momentum diffusion and pinch using off-axis torque
Name:	Keith Burrell Burrell@fusion.gat.com	Affiliation:	General Atomics
Research Area:	Plasma Rotation	Presentation time:	Not requested
Co-Author(s):	W.M. Solomon, B.A. Grierson, C. Chrystal	ITPA Joint Experiment :	No
Description:	The goal of this experiment is to determine the angular momentum diffusivity and pinch velocity from the toroidal rotation change caused by off-axis injection of angular momentum using the 150 beams.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	This work requires a specific combination of neutral beams but otherwise can be done in a whole range of plasmas. The key is to have the 30LT and 210RT beams on continuously and to modulate the 150 beams in a situation where the 150 beam is tilted to give the maximum off-axis injection. The 30LT and 210 RT beams provide CER data for both the carbon ions and the main ions. We will to use the prompt torque from the 150 beams to do a modulated angular momentum transport. By analyzing the transient response of the toroidal velocity to the modulation, we can extract the angular momentum diffusivity and pinch velocity across most of the minor radius. This experiment is best done in reverse Ip plasmas because the orbit shift of the 150 beam particles is outward, leading to a prompt torque input that is further off axis.
Background:	Modulated momentum transport work has been done recently on D III-D [Solomon et al, Nuclear Fusion 49, 085005 (2009)], JET [Tardini et al, Nuclear Fusion 49, 085010 (2009)] and JT-60U [Yoshida et al, Nuclear Fusion 47,856 (2007)]. The latter work is particularly elegant, since the modulated beam was far off axis and the analysis of the rotation response could be done using a source-free transport equation. With the advent of the off-axis neutral beam on D III-D, we can now perform similar experiments. In addition, with the new, main ion CER system, we can extend that work to study both the impurity and the main ion rotation.
Resource Requirements:	Off-axis setting of the 150 beam. 30LT and 210RT beams for CER measurements.
Diagnostic Requirements:	Main ion and carbon CER systems for rotation measurements. Complete profile diagnostics for background plasma profiles
Analysis Requirements:
Other Requirements: