1. SMK – XP 1 XP 811: Effect of Rotation on Energy/Impurity Confinement S. Kaye, L. Delgado-Aparicio Joule Milestone Description –XP directly addresses Joule milestone –Application of n=3 to vary plasma rotation; assess effect on energy confinement and transport Background –Attempts last year mixed Dedicated XP failed to produce long-lived discharges (MHD appeared early) XP740 (effect of rotation on NTM threshold) produced longer plasmas (up to 0.7 s) Some effect seen

2. SMK – XP 2 Effect of Rotation on Confinement (cont’d) Experimental Plan –Use 123848 as baseline (from XP740), or alternative (see next VG) Two NBI sources –Apply n=3 fields continuously starting from 0.3 s –Increase amplitude of n=3 current from 0 to 800 kA (or to max as set by destabilization of MHD) –Assess effect on rotation, confinement (global and local) –Impurity injection in alternate shots Time required: 1 day –Possible division into ½ + ½, depending on condition, quality of data (especially pCHERS) Special requirements –123848 (or other) as baseline discharge Need to develop MHD quiescent condition without Lithium –Poloidal and toroidal CHERS, ERD

3. SMK – XP 3 Possible Baseline Shots 121154, 121162, 4.5 kG, 1.0 MA,  B ~2.2-2.3,  T ~0.7-0.8,  B ~0.4-0.5 (2006 shot, XP613) Sources A & B @ 90 kV, and source C @ 70 kV. Turn of source C @ 300 ms 123848, 4.5 kG, 1.0 MA,  B ~2.3,  T ~0.8,  B ~0.4-0.5 (2007 shot, XP740) Sources A & C @ 90 kV. Lithium evaporated (214 mg)!

4. SMK – XP 4 Shot List Shot Development –Attempt to attain MHD quiescent condition with no Lithium, shot 123848 (2-4 shots); no n=3 braking –If this fails, attempt MHD quiescent condition with 121154 (2-4 shots); no n=3 braking –If failure in ½ day: Cut losses and move on Return later in no-Li portion of run, or with Li –If successful in either condition Increase n=3 fields in 4 to 5 steps –400 kA, 600 kA, 650 kA, 700 kA, …. until MHD shortens discharge »Ensure no large islands at any n=3 current (SXR, profiles) –3 shots/condition: no impurity injection, impurity injection @ 400 ms, no impurity injection –15-21 shots Biggest issues for this XP are –Attaining MHD quiescent condition Avoiding large islands in edge –Shot reproducibility