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Physics Basis of FIRE Next Step Burning Plasma Experiment. Charles Kessel Princeton Plasma Physics Laboratory U.S.-Japan Workshop on Fusion Power Plant Design, University of Tokyo March 29-31, 2001. http://fire.pppl.gov. Goals of the FIRE Study. - PowerPoint PPT Presentation
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Physics Basis of FIRE Next Step Burning Plasma Experiment
Charles KesselPrinceton Plasma Physics Laboratory
U.S.-Japan Workshop on Fusion Power Plant Design, University of Tokyo
March 29-31, 2001 http://fire.pppl.gov
Goals of the FIRE StudyUsing the high field compact tokamak, produce burning plasmas with Q > 5-10 over pulse lengths > 2 current diffusion times, to study and resolve both standard and advanced tokamak burning plasma physics issues, for $1B
FIRE Has Many Features Similar to ARIES Tokamaks
FIRE Looks Like a Scale Model of ARIES-AT
FIRE
~ 3X
ARIES-AT The “Goal”
B = 6 TR = 5.2 m
Pfusion = 1755 MW
Volume = 330 m3
R = 2 m B = 10 T
Pfusion = ~ 200 MW
Volume = 18 m3
Nw = 3 MW/m2
Pfus = 12 MW/m3 Nw = 3.3 MW/m2
Pfus = 5.3 MW/m3
FIRE Can Access Various Pulse Lengths by Varying BT
FIRE’s Divertor Must Handle Attached(25 MW/m2) and Detached(5
MW/m2) Operation
FIRE’s Divertor is Designed to Withstand Large Eddy Current and
Halo Current Forces
FIRE Must Handle DisruptionsVDE Simulation with 3 MA/ms Current Quench
FIRE Has Several Operating Modes Based on Present Day Physics
• Reference: ELMing H-mode– B=10 T, Ip=6.5 MA,
Q=5, t(pulse)=18.5 s
• High Field: ELMing H-mode– B=12 T, Ip=7.7 MA,
Q=10, t(pulse)=12 s
• AT Mode: Reverse Shear with fbs>50%– B=8.5 T, Ip=5.0 MA,
Q=5, t(pulse)=35 s
• Long Pulse DD: AT Mode and H-mode– B=4 T, Ip=2.0 MA,
Q=0, t(pulse)>200 s
FIRE can study both burning AND long pulse plasma physics in the same device
Progress Toward ARIES-like Plasmas Requires A Series of Steps
1) stabilize NTM’s
2) stabilize n=1 RWM
3) stabilize n>1 RWMs*each step with higher fbs
**each step with more profile control
FIRE is Examining Ways to Feedback Control RWM/Kink Modes
FIRE Must Satisfy Present Day Physics Constraints
FIRE Can Access Most of the Existing H-mode Database
FIRE’s Performance With Projected Confinement
FIRE Is Being Designed to Access Higher AT Plasmas
40
30
20
10
0
0 4 8 12 16 20 24 28 32
50
-5
Time (s)
Power (MW)
Bt
Ip
Ip
Bt
R = 2.14m, A = 3.6, 10 T, 7.7 MA, ~ 20 s flat top
Alpha Power
Auxiliary Power
Ohmic Power
1 1/2-D Simulation of Burn Control in FIRE* (TSC)
• ITER98(y,2) scaling with H(y,2) = 1.1, n(0)/<n> = 1.2, and n/n GW = 0.67
• Burn Time ≈ 18 s ≈ 21 τE ≈ 4 τHe ≈ 2 τskin
Q ≈ 13
Plasma Response to Paux Modulation
Plasma Response to Fueling Modulation
Divertor Pumping Strongly Affects Plasma Burn
TSC Simulation of FIRE Burning AT Discharge
Ip=5 MA, Bt=8.5 T, N=3.0, li(3)=0.4, n/nGr=0.7, H(y,2)=1.15, PLH=20 MW, PICRF=18 MW, n(0)/<n>=1.45
TSC Simulation of FIRE Burning AT Discharge
A Burning Device Like FIRE Must Validate Assumptions Made in Power
Plant Studies Like ARIES• Power and particle
handling in the divertor/SOL/first wall
• Stabilization of NTM’s• Stabilization of
RWM/Kink modes• Large bootstrap
fraction plasmas with external CD
• Control of current, n, and T profiles
• Develop methods to mitigate/avoid disruptions
• Demonstrate energetic particle effects are benign
• All in a plasma with significant alpha particle heating
The FIRE Design is Evolving• What can the machine do?
– Q– Pulse length– T and n variations– Heating/fueling/pumping/
current drive • What is the impact of
physics uncertainties?– Scaling of τE
– Scaling of Pth(L to H)
– NTM -limit– Density limit– Particle confinement τp*/τE
• What is machine flexibility to examine physics issues?– Burn control– AE, energetic particles– Sawteeth, other MHD– AT profile interactions (p(r),
j(r), (r))