ITPA TC15 Dependence of Momentum and Particle Pinch

ITPA TC-15, Dependence of Momentum and Particle Pinch on Collisionality, R/Ln and q T. Tala (JET, DIII-D, C-Mod, AUG), W. Solomon (DIII-D, JET, NSTX), S. Kaye (NSTX), A. Salmi (JET, DIII-D), J. Rice (C-Mod), Y. Podpaly (C-Mod), R. Mc. Dermott (AUG), G. Tardini (AUG), M. Yoshida (JT-60 U), C. Angioni (theory) + large local teams in each tokamak not listed here *

2 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Status of TC-15 Joint Experiment: Dependence of Momentum and Particle Pinch on Collisionality Colour codes: Device XXX XXX Experiment done, more proposed Experiment finished Experiment allocated time Some data exist, but not directly linked to this Joint Experiment Momentum Particle Period Local Key Person JET, 22 October 2009 XXX 2009 -2011 T. Tala / L. Garzotti DIII-D, 20 May 2009 XXX 2009 -2010 W. Solomon / L. Zeng NSTX, August 2009 XXX 2009 -2010 S. Kaye / L. Delgado. Aparicio AUG, 1 and 3 February 2011 XXX 2010 -2011 R. Mc. Dermott C-MOD, 13 January 2011 XXX 2010 -2011 J. Rice / Y. Podpaly JT-60 U XXX 2009 -2010 M. Yoshida *

3 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Outline Ø JET Ø AUG Ø DIII-D Ø C-Mod Ø Summary and Future Plans *

4 VTT TECHNICAL RESEARCH CENTRE OF FINLAND JET Analysis Progressed Well, NF Paper Is Being Written Ø Pinch number Rvpinch/χ depends strongly on the density gradient length R/Ln Rvpinch/χ ≈ 1. 2 R/Ln + 1. 4 Ø Similar dependence of the pinch on R/Ln also found in JET rotation database studies [P. de Vries, PPFC 2010, H. Weisen, EU-US TTF 2010] Data averaged over the region from r/a=0. 4 to r/a=0. 8 * Ø GS 2 simulations find similar positive trend with R/Ln, but it is weaker and very dependent on the value of R/Ln (note the large error bars in R/Ln)

5 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Outline Ø JET Ø AUG Ø DIII-D Ø C-Mod Ø Summary and Future Plans *

6 VTT TECHNICAL RESEARCH CENTRE OF FINLAND ITPA TC-15 Partly Carried Out on AUG in February 2011 Ø Modulation signal very clear and at optimum level (~5%) – demonstrating feasibility of NBI modulation technique on AUG Ø Compare cases with NBI, NBI+ICRH/ECRH clear differences in phase and amplitude with ion versus electron heating momentum transport and possibly also torque sources changed by RF *

7 VTT TECHNICAL RESEARCH CENTRE OF FINLAND The Fraction of J×B torque and Collisional Torque Different on AUG than on JET and DIII-D AUG pulse number 26241, torque from TRANSP * J×B torque collisional torque total torque

8 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Data from Pulse no. 26241 Demonstrates the Existence of the Momentum Pinch on AUG experimental modulation data simulation with Prandtl number ≈ 0. 7, vpinch=0 simulation with Prandtl number ≈ 1. 3, vpinch ≈ 10 m/s Ø Sawtooth significant inside r/a<0. 2 and is coupled to the modulation frequency Ø Analysis valid only at r/a>0. 3 *

9 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Prandtl and Pinch Number Profiles of 26241 simulation with Prandtl number ≈ 0. 7, vpinch= 0 simulation with Prandtl number ≈ 1. 3, vpinch ≈ 10 m/s *

10 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Outline Ø JET Ø AUG Ø DIII-D Ø C-Mod Ø Summary and Future Plans *

11 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Clear Rotation Modulation Signal at r/a>0. 3 on DIII-D, but Wild Things Happen at r/a<0. 3 DIII-D pulse number 137341 *

12 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Similar Test to AUG on DIII-D to See What Kind of Pinch Is Needed to Reproduce the Experimental Data *

13 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Similarly to AUG, without the Pinch, Phase Significantly Overestimated; with the Pinch, Phase Is Matched Well on DIII-D *

14 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Outline Ø JET Ø AUG Ø DIII-D Ø C-Mod Ø Summary and Future Plans *

15 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Diagnostics NBI Did Not Produce Any Observable Rotation Perturbation on C-Mod * Time (s)

16 VTT TECHNICAL RESEARCH CENTRE OF FINLAND LHCD Modulation Creates a Large Rotation Perturbation, but It Also Perturbs ne, Te and Ti * Time (s)

17 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Septum Modulation (Upper-Lower Null) Can Create a Non-Perturbative Rotation Modulation on C-Mod, Further Optimization Needed * Time (s)

18 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Outline Ø JET Ø AUG Ø DIII-D Ø C-Mod Ø Summary and Future Plans *

19 VTT TECHNICAL RESEARCH CENTRE OF FINLAND 2011 Activities for the ITPA TC-15 Experiment, Lots of Progress both on the Experimental and Analysis Sides on JET, AUG, DIII-D and C-Mod Ø JET: Finalizing the work on the parametric dependencies of the pinch and Prandtl number (NF paper). New experiments to study the β dependence of momentum pinch (TC-16) proposed for 2012 -2013. Ø DIII-D: Detailed momentum transport study using the same automated analysis technique as in JET for the NBI modulation experiment in progress. β dependence experiment (TC-16) on DIII-D proposed. First set of data published by W. Solomon et al. in Po. P 2010. Ø AUG: About 60 -70% of the TC-16 experiment performed in February 2011. The rest of TC-15 planned next week (April 12), possibly including the β dependence extension (TC-16). Initial data quality looks very good, physics scans somewhat limited by the operational space on AUG. Some data to be included in Rachael Mc. Dermott’s EPS 2011 paper. Ø C-Mod: A session on initial survey of different rotation perturbation techniques performed in January 2011. Septum sweeping found to be a promising technique. Next session (target autumn 2011) will exploit SSEP technique, with the aim to scan collisionality, density etc. Ø NSTX: Experiment performed in 2009 and analysis finished, and partly published by W. Solomon et al. in Po. P 2010. Particle transport part reported in IAEA 2010 (L. Delgado-Aparacio) *

20 VTT TECHNICAL RESEARCH CENTRE OF FINLAND Long Term Plans Ø Finish the experiments (mostly in 2011) Ø Carry out the detailed momentum transport analysis using identical tools for AUG, DIII-D and JET Ø Write an IAEA 2012 paper on the joint analysis including the multi -tokamak scans of collisionality, R/Ln, q, density, … Ø Close the TC-15 JEX in the autumn 2012 *