ARIES-ACT1 preliminary plasma description
description
Transcript of ARIES-ACT1 preliminary plasma description
ARIES-ACT1 preliminary plasma description
C. Kessel, PPPL
ARIES Project Meeting, October 13, 2011
Systems configuration to detailed configuration (JSOLVER equilibrium)
Systems Detailed ARIES-AT
R, m 5.5 5.5 5.2
IP, MA 10.6 10.0 12.8
βN 4.5 4.83 5.45
BT, T 5.5 5.5 5.86
n/nGr 0.95 0.87 1.0
n(0)/<n>v 1.3 1.37 1.35
T(0), keV 26.8 26.4 31.2
<T>v, keV 16.6 15.9 15.9
IBS, MA 9.54 8.35 11.65
ICD, MA (on,off-axis)
1.06 1.3 (0.38, 0.95) 1.28
Free-boundary equilibriumConverging on profiles between free and fixed boundary equilibria
If other other values of δ, ςo,I are found to be good for stability we can modify
Using coil set like ARIES-AT, will optimize coil locations later
κx = 2.21δx = 0.77ςo,I = 0li(1) = 0.54βN = 4.77q95 = 3.53
control point
Fixed boundary equilibria, preliminary operating point
Mismatch of inner flux surfaces is from profile differences
total jtoroidal
self-driven jtoroidal
Alignment of boundaries is very good.
Fixed boundary equilibria, preliminary operating point, cont’d
Pedestal in pressure, T, n
bootstrap currentIC or EC on-axis currentLH off-axis current
n = ne+Σni
Ip = 10 MAκ = 2.15δ = 0.7ςo,I = 0q(0) = 3.25qmin = 2.3βN = 4.83Li(1) = 0.49
p(0)/<p> = 2.06T(0)/<T> = 1.66n(0)/<n> = 1.37ne(0) = 1.97x1020
Pped ~ 175 kPa, approximately what we expect from EPED
Te = Ti
Ideal MHD stability of high-n ballooning and external kink modes
Ballooning unstable on 4 out of 200 surface, all outside pedestal locationWeak instabilities, high critical-n number, should use EPED stability analysis for this region
External kink modes (using conformal wall, unstable with no conducting wall)
Mode number b/a to stabilize (real distance from plasma surface)
n = 1 0.46 (0.633 m)
n = 2 0.45 (0.619 m)
n = 3 0.425 (0.584 m)
Will pursue higher mode numbers, n=4-6, to determine most limiting
Further work• Examine stability with and without off-axis CD, profile adjustments to
accommodate transport or better stability– Check stability convergence
• Converge free-and fixed boundary equilibria, include different shaping if necessary
• Develop consistent heating and CD, time-dependent scenario– Converge PPPL and GA results
• Examine plasmas at higher βN, similar to ARIES-AT, limited by b/a(kink) ~ 0.33, compare with what we are choosing
– We have backed away from the highest βN values since experiments don’t appear to access these plasmas…..so what would the right parameters be?
– Should the wall be placed at 0.33, with lower βN, providing a % toward the with wall limit?– Based on what experimentalists observe, what would they project for βN, βN/βN
wall, q95, etc.
• Examine ACT2 candidates