1. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division J.H. Schultz M.I.T. Plasma Science and Fusion Center NSO PAC 2 Meeting M.I.T. Plasma Science and Fusion Center January 17-18, 2001

2. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division 1. IPB98(y.2) Scaling - reduced 2.0 m Wedged FIRE from Q=10 to Q=5 at 10 T - parametric study explores bucked/wedged option for cost/mission improvements 2. Equalization of TF/CS "burn times" - optimization of TF/CS interface 3. Scan of A, Bt for "Fixed Mission" - Margin=2 and Margin=1 4. Detailed Cost vs. Ro Sensitivities

3. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division

4. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division (1) TF/OH interface optimization t burn,TF = t burn,OH (TF/OH interface optimum for fixed Ro Subtract 3 s from TF flattop for heating e.g. 24.5 s flattop = 24.5 s I flattop = 3 s heat + 21.5 s burn No scaling of t heat with plasma parameters (2) Minimum Ro for "Mission Margin" Mission: Long-pulse  -dominated plasmas Margin=2: Q>=10; t flattop /max(  E,  p *,  J ) >= 2 Margin=1: Q>=5; t flattop /max(  E,  p *,  J ) >= 1

5. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division Instead of fixing Ro and varying A Vary Ro and A, while holding Margin=1,2 Margin=min(P  /P heat, t flattop /  J ) 3 Variations: 1) Minimum Ro(fixed A,B)with M=min(P  /P heat, t flattop /  J ) 2) Minimum Ro(fixed A, Bvariable @ low A); M=Const 3) Minimum Ro(fixed A,B, f(q) @ high B); M=Const

6. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division Alpha margin=Time margin=2 at optimum A=2.0/0.525 Rapid rise in time margin and heating margin off optimum A

7. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division Reduced Mission: M=1, Q=5,t burn /  J =1 R o,min = 1.59 m at Bt=11.5 T & A=(2.0/0.525)=3.8095 Bt=11.5 T for A=3.8 Bt=10.5 T for A=3.6 R(low A) nonlinear, but not pathological

8. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division R o (m) grows pathologically at high B t and q lim =3.1 Well-behaved if M=2,Q=10,t/  J =2 (q lim > 3.1 at B t >B t,opt) R omin =1.86 m, A=3.8 R omin (A=3.6) = 1.925 m

9. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division R omin = 1.86 m@ B t =11.5, A=3.8 R o (m) pathological at low A Cured by lowering B t ; Q=10, M=2 (no effect on R omin )

10. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division M2:Minimum Cost =$1.06 B @ R o = 1.86 m, A=3.8, B t =11.5 T - M2 < $1 B, if phase auxiliary power M1:Minimum Cost = $0.92 B @ R o =1.59 m, A=3.8, B t =11.5 T

11. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division Vary R o ; B t =11.5 T, A=3.8, q L =3.1, not fixed mission $/Ro Sensitivity = 1.01 $/Ro: Paux, I&C = 0 Magnets=1.64 Basic Machine=1.25 Buildings=1.14

12. MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division R o can be reduced to 1.86 m and retain M=2 mission Mission reduction x 2 allows reduction of R o to 1.59 m (1st order!) Margin=2 mission requires lowering B @ A 13 T d$/dR = 1: Machine sensitivity ~ 1.25 + nearly fixed costs Recommendation: Reduce R o to 1.87 m, Day 1 RF = 10 MW Achieve all cost/mission objectives: Q=10,  flat /  J =2, Cost<$1 B Historic first: A noncatastrophic reduction in NSO R o