scaling of impurity (ne & ar) transport in beam heated nstx h-mode discharges l. f....
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Scaling of impurity (Ne & Ar) transport in beam heated NSTX H-mode discharges
L. F. Delgado-Aparicio, D. Stutman, K. Tritz, and M. FinkenthalThe 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. YuhNOVA Photonics, Inc.
J. Lepson and P. BeiersdorferUniversity 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
GOAL: Continue with the particle transport characterization of H-mode plasmas
(L. F. Delgado-Aparicio, APS-DPP, 2006)
Diffusion• Dneon 1/B2 satisfying neoclassical scaling
laws and Dneon ~ Di, i,(TRANSP).
Convective velocity• The initial slow core penetration (~100ms)
with a peaking of neon density late in time (NSTX # 121165NSTX # 121165), suggests the presence of an inward pinch (convective) velocity.
• For the high field case (NSTX # 121174NSTX # 121174), the positive (radially outwards) convective velocity explains the “shielded” low level of impurities in NSTX inner half.
First estimates of First estimates of DD and and VVCC in in ** scaling experiments scaling experiments
Type of plasmas neededType of plasmas needed
NBI requirements• Sources A & B @ 90 kV, and source C @ 70 kV
• Turn of source C @ 300 ms
NSTX 121154, 121162, 4.5 kG, 1.0 MA NSTX 121154, 121162, 4.5 kG, 1.0 MA
Shot matrix for 1st half of the day (Neon injections)
Dial 2006 baseline + Ne injection (121154/121162 but @ 5.5 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-total 10 shots
• Neon injections @ 350 ms for t~50 ms, 1.5Torr·l/s
• Controlled access to change gases (for Ar injection): ~60 minutes ?
Ip scaling at B=5.5 kG
B scaling at Ip=0.9 MA
Shot matrix for 2nd 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-total 8 shots
Compare with 2006 Ne
injections @ ~constant BIp
2-point B and Ip scaling to
compare with neon
• Argon injections @ 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