Implications of Recent Physics Advances for the Design and Operation of Burning Plasma Experiments such as ITER and FIRE

1
Implications of Recent Physics Advances for the
Design and Operation of Burning Plasma
Experiments such as ITER and FIRE
Dale Meade Princeton Plasma Physics
Laboratory Symposium on Fusion
Engineering Knoxville, TN September 27, 2005
2
ARIES Studies have Defined the Plasma
Requirements for an Attractive Fusion Power Plant
and hence DEMO
Plasma Exhaust Pheat/Rx 100MW/m Helium
Pumping Tritium Retention
High Gain Q 25 - 50 ntET 6x1021
m-3skeV Pa/Pheat fa 90 Low rotation
Plasma Control Fueling Current Drive RWM
Stabilization
High Power Density Pf/V 6 MWm-3 p 10 atm Gn 4
MWm-2
Steady-State 90 Bootstrap
Significant advances are needed in each area. A
Broad International Approach is needed to provide
the RD Needed for DEMO
3
Advanced Toroidal Physics (100 Non-inductively
Driven AT-Mode) Q 5 as target, higher Q not
precluded fbs Ibs/Ip 80 as target,
ARIES-RS/AT90 bN 4.0, n 1 wall stabilized,
RWM feedback
Quasi-Stationary Burn Duration (use plasma time
scales) Pressure profile evolution and burn
control gt 20 - 40 tE Alpha ash
accumulation/pumping gt 4 - 10 tHe Plasma current
profile evolution 2 to 5 tskin Divertor
pumping and heat removal gt 10 - 20 tdivertor
First wall heat removal gt 1 tfirst-wall
4
FIRE is Based on ARIES-RS Vision for DEMO

• 40 scale model of ARIES-RS plasma
• ARIES-like all metal PFCs
• Actively cooled W divertor
• Be tile FW, cooled between shots
• Close fitting conducting structure
• ARIES-level toroidal field
• LN cooled BeCu/OFHC TF
• ARIES-like current drive technology
• FWCD and LHCD (no NBI/ECCD)
• No momentum input
• Site needs comparable to previous
• DT tokamaks (TFTR/JET).
• T required/pulse TFTR 0.3g-T

5
Fusion Ignition Research Experiment (FIRE)

• R 2.14 m, a 0.595 m
• B 10 T, ( 6.5 T, AT)
• Ip 7.7 MA, ( 5 MA, AT)
• PICRF 20 MW
• PLHCD 30 MW (Upgrade)
• Pfusion 150 MW
• Q 10, (5 - 10, AT)
• Burn time 20s (2 tCR - Hmode)
• 40s (lt 5 tCR - AT)
• Tokamak Cost 350M (FY02)
• Total Project Cost 1.2B (FY02) at new site.

1,400 tonne LN cooled coils
Mission to attain, explore, understand and
optimize magnetically-confined fusion-dominated
plasmas
6
Continued Progress on Existing Tokamaks Improves
FIRE and ITER Design Basis since FESAC and NRC
Reviews

• Extended H-Mode and AT operating ranges
• Benefits of FIRE high triangularity, DN and
  moderate n/nG
• Extended H-Mode Performance based ITPA scaling
  with reduced b degradation, and ITPA Two Term
  (pedestal and core) scaling (Q gt 20).
• Hybrid modes (AUG, DIII-D,JET) are excellent
  match to FIRE n/nG, and projects Q gt 20.
• Slightly peaked density profiles (n(0)/ltngt
  1.25)enhance performance.
• Elms mitigated by high triangularity, disruptions
  in new ITPA physics basis will be tempered
  somewhat.

7
New ITPA tE Scaling Opens Ignition Regime for FIRE
New Scaling
Old Scaling
Unstable side
Stable side
Q 30
Q 15
Systematic scans of tE vs b on DIII-D and JET
show little degradation with b in contrast to the
ITER 98(y, 2) scaling which has tE b-0.66 A
new confinement scaling relation developed by
ITPA has reduced adverse scaling with b see eq.
10 in IAEA-CN-116/IT/P3-32. Cordey et al. A
route to ignition is now available for the wall
stabilized regime bN 3.
8
FIRE Conventional H-Mode Operating Range Expanded
Nominal operating point Q 10 Pf 150 MW,
5.5 MWm-3 Gn 2 MWm-2 Power handling
improved Pf 300 MW, 10 MWm-3 Physics basis
improved (ITPA) DN enhances tE, bN DN
reduces Elms Hybrid mode has Q
20 Engineering Design Improved Pulse
repetition rate tripled divertor baffle
integrated
Advanced DEMO power density of 5 - 10 MWm-3 could
be produced.
9
Advanced Tokamak Operation of a Burning Plasma is
needed to Provide Physics Design Basis of DEMO

• H-Mode and hybrid mode do not provide the basis
  for an attractive steady-state DEMO.
• AT operation based on reversed (negative) shear
  with high bootstrap fraction (gt80), high bN 4
  approaches regime needed for DEMO.
• Fortunately, both FIRE and ITER can operate in
  the AT regime.

10
Steady-State High-b Advanced Tokamak Discharge
on FIRE
Pf/V 5.5 MWm-3 Gn 2 MWm-2 B 6.5T bN
4.1 fbs 77 100 non-inductive Q 5 H98
1.7 n/nGW 0.85 Flat top Duration 48 tE
10 tHe 4 tcr
FT/P7-23
11
FIRE AT Mode Limited by First Wall not TF Coil
Nominal operating point Q 5 Pf 150 MW,
Pf/Vp 5.5 MWm-3 (ARIES) steady-state
4 to 5 tCR Physics basis improving (ITPA)
required confinement H factor and bN
attained transiently C-Mod LHCD experiments
will be very important First Wall is the main
limit Improve cooling revisit FW design
12
(No Transcript)
13
Opportunities to Optimize FIRE for the Study of
ARIES AT Physics and Plasma Technologies
ARIES AT (bN 5.4, fbs 90)
12
0 50 100 time (sec)
14
First Results from ITER-AT Studies Using
TSC,TRANSP and NOVA-K
Goal is Steady-State, bN 3.5, fbs gt 60 fbs , Q
gt 5 using NINB, ICFW and LHCD
First case has bN 2.5, fbs 44, 97
non-inductive and Q 5.
C. Kessel et al Simulations of ITER Hybrid
Operating Mode-SOFE 1A-108
15
Applying FIRE-Like RWM Feedback Coils to ITER
Increases b-limit for n 1 from bN 2.5 to 4
VALEN Analysis Columbia University
G. Navratil, J. Bialek Columbia University
RWM Coil Concept for ITER
Baseline RWM coils located outside TF coils
FIRE-like RWM coils would have large stabilizing
effect on n1
Integration and Engineering feasibility of
internal RWM coils is under study.
16
ITER with FIRE would provide a strong basis for
Adv. DEMO
FIRE
ARIES-RS
ITER
ITER FIRE ARIES-RS
Fusion Gain 10(H), 5(AT) 10(H), 5(AT) 25 (AT)
Fusion Power (MW) 500 - 350 150 2170
Power Density(MWm-3) 0.6 5.6 6.2
Wall Loading Gn(MWm-2) 0.6 2 4
Pulse Duration (s) (tCR, equilibrated) 500 - 3000 2 -10, 86 - gt99.9 20 - 35 2 - 5, 86 - gt99 20,000,000 steady
Mass of Fusion Core (tonnes) 23,000 1,400 13,000
17
Concluding Remarks
Both ITER and FIRE could operate in the AT
regime, but to more fully exploit AT operation
some modifications would be needed. Areas of
additional RD for FIRE and ITER include
high power density all metal PFCs and actively
cooled first wall internal feedback coils to
allow higher beta (power-density) plasmas
Optimization of FIRE design based on AT
operation. A Broadened Approach with FIRE as
a supporting burning plasma experiment would
reduce ITER Technical risk and help fully exploit
ITERs ultimate capability to provide the basis
for an advanced DEMO.
18
Status and Plans for FIRE
DOE Physics Validation Review of FIRE passed.
March 30-31, 2004 FIRE Pre-Conceptual
Activities are completed. September
30, 2004 Ready to begin FIRE Conceptual
Design Activities. Now
Assessing feasibility of using AT as design basis
for FIRE AT progress (DIII-D, JT-60U, JET,
C-Mod) is nearly there required values of
bN, H(y,2), fbs, q, n/nG achieved but not
simult Assessing impact of using AT as design
basis for FIRE B 7T would allow use of OFHC
TF reducing coil construction costs and coil
power while allowing increased pulse lengths.
Cost savings from coils and power supplies would
be used to offset costs of active cooling of
first wall and current drive system. Optimize
FIRE parameters using AT as the design
basis. (Future)
19
The proposed RWM Coils would be in the Front
Assembly of Every other Mid-Plane Port Plug
Assembly except for the Four NBI ports.
RWM coils located behind shielding module on Port
Plug