# Presentation: 773491

## Slide 1

## FIRE 

**FIRE**** **
**Exploring the Plasma Physics**
** ****of an Advanced Fusion Reactor**

**Dale Meade**
**Forum on the Future of Fusion**
**Fusion Power Associates**
**November 19-21,2003**

## Slide 3

## Topics to be Discussed

-   Vision for Magnetic Fusion Power Plant
-   Conventional Mode Operation in FIRE
-   Advanced Mode Operation in FIRE
-   O-D Systems analysis
-   1.5-D Tokamak Code Simulation
-   RWM Stabilization Concept
-  Issues Needing R&D
- Concluding Remarks

## ARIES Economic Studies have Defined the Plasma Requirements for an Attractive Fusion Power Plant

**High Power Density**
- ~ 6 MW-3
- ~10 atm

**High Power Gain**
- Q ~ 25 - 50
- nET ~ 6x1021 m-3skeV
- P/Pheat = f ≈ 90%

**Steady-State**
- ~ 90% Bootstrap

**ARIES Economic Studies have Defined the Plasma Requirements for an Attractive Fusion Power Plant**

**Plasma Exhaust**
- Pheat/Rx ~ 100MW/m
- Helium Pumping
- Tritium Retention

**Plasma Control**
- Fueling
- Current Drive
- RWM Stabilization

- Significant advances are needed in each area.
- In addition, the plasma phenomena are non-linearly coupled.

## Slide 6

## Slide 7

##       Attractive Reactor Regime is a Big Step From Today  

**      ****Attractive Reactor Regime is a Big Step From Today  **

- Modification of
- JT60-SC Figure

## Fusion Development Considerations for FIRE

- •  Address key physics issues for an advanced reactor
- 	•  burning plasma scenarios similar to ARIES
- 	•  controlled burn of high power density plasma with Q >5, fBS ≈ 80%
- •  Focus technology on areas coupled to the plasma
- 	•  high power density plasmas
- 	•  plasma facing components
- 	•  plasma control technologies
- •  Limit scope/size of the device
- 	•  size comparable to today’s largest tokamaks to reduce cost
- 	•  only integrate items that are strongly coupled: plasma-PFCs

**These are some of the biggest challenges for fusion,**
** ****success in these areas would lead to an attractive Demo.**

## Fusion Ignition Research Experiment  (FIRE)

**Fusion Ignition Research Experiment  (FIRE)**

-  **R = 2.14 m,  a = 0.595 m**
** ****B = 10 T,      (~ 6.5 T, AT)**
** ****I****p****  = 7.7 MA, (~ 5 MA, AT)**
** ****P****ICRF**** = 20 MW**
** ****P****LHCD**** ≤ 30 MW (Upgrade)**
** ****P****fusion**** ~ 150 MW**
** ****Q ≈ 10,  (5 - 10, AT)**
** ****Burn time ≈ 20s (2 ********CR ****- Hmode)**
**      ≈ ****40s (< 5 ********CR ****- AT)**
** ****Tokamak Cost = $350M (FY02)**
** ****Total Project Cost = $1.2B (FY02)**

**1,400 tonne**
**LN cooled coils**

**Mission: to attain, explore, understand and optimize magnetically-confined fusion-dominated plasmas**

## Characteristics of FIRE

**Characteristics of FIRE**

-  40% scale model of ARIES-RS plasma
-  All metal PFCs
-  Actively cooled W divertor
-  Be tile FW, cooled between shots
-  T required/pulse ~ TFTR ≤ 0.3g-T
-  LN cooled BeCu/OFHC TF
-  no neutron shield, allows small size
-  3,000 pulses @ full field (H-Mode)
-  30,000 pulses @ 2/3 field (AT-mode)
-  X3 repetition rate since SNMS
-  Site needs comparable to previous
-      DT tokamaks (TFTR/JET).

## FIRE Plasma Systems are Similar to ARIES-AT

** **x = 2.0, x = 0.7
- Double null divertor
- Very low ripple 0.3%  (0.02%)

- NTM stability: LH current profile modification (’) at (5,2) @ 10T ECCD @ 180 GHz, Bo = 6.6T

- No ext plasma rotation source
- Vertical and kink passive stability: tungsten structures in blanket, feedback coils behind shield
- n=1 RWM feedback control with coils - close coupled

- 80 (90%) bootstrap current
- 30 MW LHCD and  5 MW (25 MW capable) ICRF/FW for external current drive/heating

- Tungsten divertors allow high heat flux
- Plasma edge and divertor solution: balancing of radiating mantle and radiating divertor, with Ar impurity

- n/nGreenwald ≈ 0.9, (ARIES-AT)
-     H(y,2) = 1.4 (ARIES-AT)
- High field side pellet launch allows fueling to core, and P*/E= 5 (10) allows sufficiently low dilution

## FIRE Plasma Regimes

**Operating Modes**
- •  Elmy H-Mode
- •  Improved H-Mode
- •  Reversed Shear AT
- 	-  OH assisted
- 	**- “steady-state”**
**	****    ****(100% NI)**

- 	**H-Mode**	**AT(ss)****	****ARIES-RS/AT**
- R/a	   3.6	 3.6		    4
- B (T) 	  10 	 6.5  	 	  8 - 6
- Ip  (MA) 	  7.7 	 5 		12.3-11.3
- n/nG	   0.7	0.85		1.7-0.85
- H(y,2)	  1.1	1.2 – 1.7		0.9 - 1.4
- N	  1.8	≤ 4.2		4.8 - 5.4
- fbs ,%	  25	 ~77		88 - 91
- Burn/CR	   2	 3 - 5		steady

- •  H-mode facilitated by x= 0.7, x = 2, n/nG= 0.7,  DN reduction of Elms.

- • AT mode facilitated by strong shaping, close fitting wall and RWM coils.

## Slide 14

## 0-D Power/Particle Balance Identifies Operating Space for FIRE - AT

- Heating/CD Powers
- ICRF/FW, ≤ 30 MW
- LHCD, ≤30 MW
- Using CD efficiencies
- (FW)=0.20 A/W-m2
- (LH)=0.16 A/W-m2
- P(FW) and P(LH) determined at r/a=0 and r/a=0.75
- I(FW)=0.2 MA
- I(LH)=Ip(1-fbs)
- Scanning Bt, q95, n(0)/<n>, T(0)/<T>, n/nGr, N, fBe, fAr

- Q= 5 - 10
- Constraints:
- flattop/CR determined by VV nuclear heat (4875 MW-s) or TF coil (20s at 10T, 50s at 6.5T)
- P(LH) and P(FW) ≤ max installed powers
- P(LH) + P(FW) ≤ Paux
- Q(first wall) < 1.0 MWm-2 with peaking of 2.0
- P(SOL) - Pdiv(rad) < 28 MW
- Qdiv(rad) < 8 MWm-2

**Generate large database and then screen for viable points**

## Slide 16

## ARIES-like AT Plasmas with Q ≈ 10 in FIRE

- Q = 5 - 10 accessible
- N = 2.5 - 4.5 accessible
- fbs = 50 - 90+ accessible
- flat/CR = 1 - 5 accessible

- If we can access.....
- H98(y,2) = 1.2 - 2.0
- Pdiv(rad) = 0.5 - 1.0 P(SOL)
- Zeff = 1.5 - 2.3
- n/nGr = 0.6 - 1.0
- n(0)/<n> = 1.5 - 2.0

## time,(current redistributions) 

**“****Steady-State” High-******** Advanced Tokamak Discharge on FIRE**

- 0               1                 2                 3                4

- time,(current redistributions)

## q Profile is Steady-State During Flattop,

** ****t=10 - 41s  ~ 3.2 ********CR**

- li(3)=0.42

- Profile Overlaid every 2 s
- From 10s to 40s

## Slide 20

## FIRE Plasma Technology Parameters

**All Metal PFCs**
- •  W divertor
- •  Be coated Cu tiles FW
**Power Density ~ARIES**
- • divertor - steady-state - water cooled,  ~ 2s
- • First wall tiles - cooled
-   between pulses  ~40s

- 	**H-Mode**	**AT(ss)****	****ARIES-RS/AT**
- R/a	   3.6	 3.6		    4
- B (T) 	  10 	 6.5  	 	  8 - 6
- Ploss/Rx (MW/m)	  17 	 23 		94 - 66
- Prad-div (MWm-2)	    5	 < 8		    5
- Prad-FW (MWm-2)	  0.3	 0.5		   <0.5
- Pfusion (MWm-2) 	 5.5	 5.5		 6 - 5.3
- n (MWm-2) 	  2	 2		 4 - 3.3
- Pn(MWm-3), VV	  25	 25		50 - 40

- •  The FIRE divertor would be a significant step toward an ARIES-like DEMO divertor.

- •  FIRE AT performance is presently limited by the first wall power (, n) handling.

## R&D Needed for Advanced Tokamak Burning Plasma

- •  Scaling of energy and particle confinement needed for projections of performance and ash accumulation.  Benchmark codes using systematic scans versus density, triangularity, etc.
-  •  Determine effect of high triangularity and double null on confinement, -limits, Elms, and disruptions.
- •  Continue RWM experiments to test theory and determine hardware requirements.  Determine feasibility of RWM coils in a burning plasma environment.
-  •  Improve understanding of off-axis LHCD and ECCD including effects of particle trapping, reverse CD lobe on edge bootstrap current and Ohkawa CD.
- •  Development of a self-consistent edge-plasma-divertor model for W divertor targets, and incorporation of this model into core transport model.

## Areas of Major FIRE Activities for the Near Term

- 		( A, SN/DN, N, fbs, ......)
- 	 - RWM Stabilization - What is required and what is feasible?
- 	 - Integrated Divertor and AT
- 	 - Plasma Control (fast position control, heating, current-drive, fueling)
**•  ****High Power Density** Plasma Facing Components Development
- 	 - High heat flux, low tritium retention
**•  ****Diagnostic Development** and Integration
**•  ****Integrated Simulation** of Burning Plasmas

**Areas of Major FIRE Activities for the Near Term**

**• ****The goal is to develop advanced operating modes that  can be used as the design basis for FIRE.**** **

## Concluding Remarks

- • There are a number of high leverage physics R&D items to be worked on for operation in the conventional mode and the advanced mode for FIRE and ITER.   There needs to be an increased emphasis on physics R&D for advanced modes and high power density PFCs that lead to an attractive fusion reactor.
-  • The U.S. Administration has shown an interest in fusion and has approved joining the ITER negotiations.  Congress has also shown interest with Authorization bills that support ITER if it goes ahead, and support FIRE if ITER does not go ahead. This is consistent with the consensus in the U.S. fusion community.

**Concluding Remarks**

## The Terra Cotta Warriors have returned to fight for fusion.

**The Terra Cotta Warriors have returned to fight for fusion.**