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ARIES-ACT1 preliminary plasma description. C. Kessel, PPPL ARIES Project Meeting, October 13, 2011. Systems configuration to detailed configuration (JSOLVER equilibrium). Free-boundary equilibrium. control point. Converging on profiles between free and fixed boundary equilibria
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ARIES-ACT1 preliminary plasma description C. Kessel, PPPL ARIES Project Meeting, October 13, 2011
Systems configuration to detailed configuration (JSOLVER equilibrium)
Free-boundary equilibrium control point Converging 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 = 2.21 δx = 0.77 ςo,I = 0 li(1) = 0.54 βN = 4.77 q95 = 3.53
Fixed boundary equilibria, preliminary operating point Alignment of boundaries is very good. total jtoroidal self-driven jtoroidal Mismatch of inner flux surfaces is from profile differences
Fixed boundary equilibria, preliminary operating point, cont’d Ip = 10 MA κ = 2.15 δ = 0.7 ςo,I = 0 q(0) = 3.25 qmin = 2.3 βN = 4.83 Li(1) = 0.49 Te = Ti p(0)/<p> = 2.06 T(0)/<T> = 1.66 n(0)/<n> = 1.37 ne(0) = 1.97x1020 bootstrap current IC or EC on-axis current LH off-axis current n = ne+Σni Pedestal in pressure, T, n Pped ~ 175 kPa, approximately what we expect from EPED
Ideal MHD stability of high-n ballooning and external kink modes • Ballooning unstable on 4 out of 200 surface, all outside pedestal location • Weak instabilities, high critical-n number, should use EPED stability analysis for this region • External kink modes (using conformal wall, unstable with no conducting wall) 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/βNwall,q95, etc. • Examine ACT2 candidates