Scaling of impurity (Ne & Ar) transport in beam heated NSTX H-mode discharges L. F. Delgado-Aparicio, D. Stutman, K. Tritz, and M. Finkenthal The Johns Hopkins University, The Plasma Spectroscopy Group R. E. Bell, R. Kaita, S. Kaye, B. P. LeBlanc, S. Paul, L. Roquemore and D. Smith Princeton Plasma Physics Laboratory F. Levinton, H. Yuh NOVA Photonics, Inc. J. Lepson and P. Beiersdorfer University of California - Berkeley & Lawrence Livermore National Laboratory NSTX, XP 613 (2007 T&T Review) March 27th, 2007 Princeton, New Jersey, USA

GOAL: Continue with the particle transport characterization of H-mode plasmas

(L. F. Delgado-Aparicio, APS-DPP, 2006) Diffusion D neon  1/B 2 satisfying neoclassical scaling laws and D neon ~ D i,  i, (TRANSP). Convective velocity NSTX # The initial slow core penetration (~100ms) with a peaking of neon density late in time (NSTX # ), suggests the presence of an inward pinch (convective) velocity. NSTX # For the high field case (NSTX # ), the positive (radially outwards) convective velocity explains the “shielded” low level of impurities in NSTX inner half. First estimates of D and V C in  * scaling experiments

Type of plasmas needed NBI requirements Sources A & 90 kV, and source 70 kV Turn of source 300 ms NSTX , , 4.5 kG, 1.0 MA

Shot matrix for 1 st half of the day (Neon injections) Dial 2006 baseline + Ne injection (121154/ kG, 1.0 MA) 2 shots Baseline + Ne injection (5.5 kG, 1.2 MA) 2 shot Baseline + Ne injection (5.5 kG, 0.9 MA) 2 shots Baseline + Ne injection (4.5 kG, 0.9 MA) 2 shots Baseline + Ne injection (4.0 kG, 0.9 MA) 2 shots Sub-total10 shots Neon 350 ms for  t~50 ms, 1.5Torr·l/s Controlled access to change gases (for Ar injection): ~60 minutes ? I p scaling at B  =5.5 kG B  scaling at I p =0.9 MA

Shot matrix for 2 nd half of the day (Argon injections) Dial 2006 baseline + Ar injection (121154/121162, 4.5 kG, 1.0 MA) 2 shots Baseline + Ar injection (4.0 kG, 0.9 MA) 2 shot Baseline + Ar injection (5.5 kG, 1.2 MA) 2 shots Baseline + Ar injection (5.5 kG, 0.9 MA) 2 shots Sub-total8 shots Compare with 2006 Ne ~constant B   I p 2-point B  and I p scaling to compare with neon Argon 350 ms for  t~50 ms, 0.5 Torr·l/s If time permits: a) repeat 4.5 kG, 1.0 MA but for injection at 0.75 Torr·l/s b) include 5.5 kG, 1.0 MA & 4.5 kG, 0.9 MA D. Gates wants to asses the impact of Ar injection in the background plasma