# Presentation: 137130

## FIRE 

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

**Dale Meade**
**FIRE Physics Validation Review**
**DOE Germantown, MD**
**March 30, 2004**

## Topics to be Discussed

-   NSO/FIRE Mission, Objectives
-   Critical Issues for Burning plasma Experiment
-   Readiness to Address Critical Issues
-   Status of FIRE (Progress since Snowmass)
-   Characteristics of FIRE
-   Conventional Mode Operation
-   Advanced Mode Operation
-  Future FIRE/US Burning Plasma Activities
- Issues Needing R&D
-  Concluding Remarks

## What is the NSO

- • NSO  Charter etc
- • FIRE Department
- • budgets
- • NSO-PAC

## Why are we having a FIRE PVR?

- • FESAC reviews calls for PVR of FIRE
- • NRC
- • ITER negotiations are still in process
- • Decision Schedule for BP
- 	plan A - ITER
- 	plan B - FIRE

## •  Are the mission and objectives identified by FIRE appropriate to answer the critical burning plasma issues in a major next step experiment?

- • Is the proposed physical device sufficiently capable and flexible to answer the critical burning plasma issues proposed?
- • What areas are deficient and what remedies are recommended?
- • What areas need supporting R&D from the base program (experimental, theory and modeling)?
- Agenda

**Charge to PVR Committee**

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

**High Power Density**
- Pf/V~ 6 MW-3
- ~10 atm
- n ≈ 4 MWm-2

**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.
- A burning plasma should address the key plasma issues for an attractive PP.

## The overarching  issue for a burning plasma is whether 

**The overarching  issue for a burning plasma is whether **
**a self-heated plasma with a self-generated confining magnetic field can be created and controlled.**

## Slide 8

## Slide 9

## 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).

## Slide 12

## 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 is Aims to Address Issues Related to an Attractive PP  

**FIRE is Aims to Address Issues Related to an Attractive PP  **

- Modification of
- JT60-SC Figure

## Slide 15

## Slide 16

## FIRE Could Access Confinement Similar to ARIES-RS

**FIRE Could Access Confinement Similar to ARIES-RS**

- Tokamaks have established a   basis for scaling confinement of the diverted H-Mode.
-  BE is the dimensionless metric for confinement time projection
-  nET is the dimensional metric for fusion                                                  	- nET = B2E = B . BE
-  ARIES-RS Power Plants require BE slightly larger than FIRE due high  and B.

## 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 19

## FIRE, the Movie

**FIRE, the Movie**

- Simulation of a Standard H-mode in FIRE - TSC
- 	• CTM ≈ GLF23
- 	• m = 1 sawtooth Model - Jardin et al
- 	• other effects to be added - Jardin et al

## Insert Snowmass Assessment of FIRE

- • confinement - OK
- • NTMs
- • Elm/disruption power handling
- • plasma pulse length
- 	H-mode same as ITER(2tcr)
- 	AT mode, not steady
- • diagnostics
- 	integration with FW
- 	AT diagnostics (beam seeded)
- • long time between shots
- • insulation

## Confinement Projections Improved

- •  New two term scaling published by ITPA leads to Q > 10 for FIRE
- • JET DEMO shot for FIRE (JET 52009)
- •  High triangularity and modest n/nGW in existing experiments continues to lead to enhanced confinement.
- •  C-Mod experiments show slightly improved confinement for DN
- •  Recent experiments with DIII-D Hybrid mode projects to Q ≈ 20
- •

## High triangularity and Double Null Enhance MHD stability

- • VG from DIII-D budget meeting
- • VG from recent Pamela talk

## 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 26

## 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.

## Plasma Handling Requirements for a PP

**Plasma Handling Requirements for a PP**

- The FIRE first wall requirements are higher than ITER and comparable to ARIES.
-  It is an issue that needs to be addressed.

- Draft VG

## 25 MW/m2

- 25 MW/m2

## 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.

## Slide 31

## Plan B:  No Decision is made to Construct ITER

- • An alternative to ITER must be put forward before interest in BPP is lost.
- • Put FIRE forward immediately as recommended by:
- 	• FESAC - FIRE should “be advanced as a U.S.-based burning plasma experiment with strong encouragement of international participation”
- 	• Energy Policy Act of 2003 - introduced in the Senate on Feb 11, 2004 -       “If at any time during  the negotiations on ITER, the Secretary determines that  construction and operation of ITER is unlikely or infeasible, the Secretary shall send to Congress, as part of the  budget request for the following year, a plan for implementing the domestic burning plasma experiment known as FIRE, including costs and schedules for such a plan.”
- • Similar recommendation has been made for the EU program by Airaghi (2000)
- 	• “In the same 2-year period(2001-2002), due to the uncertainty over the outcome of the international negotiations, Europe should study an alternative to New-ITER, which would be suitable to be pursued by Europe alone. For example, a copper magnet machine which would still achieve the required objective of demonstrating a burning plasma under reactor conditions even if this would delay the integration of the superconducting technologies.”

## Slide 33

## Plan B:  Major Near Term  Activities (to = July 04)

- • Physics Validation Review (update of Snowmass and NSO reviews) Mar 30, 04
- •  Formation of a national FIRE organization				Aug 04
- •  Initiation of discussions with potential international collaborators	Aug 04
- •  Form FIRE Project Management team				Sep 04
- •  CD-0 Approve Mission Need  					Oct   04
- •  Community Workshop on Prep for FIRE Conceptual design		Nov  04
- •  Finalize Plan for FIRE Conceptual Design				Nov 04
- •  Initiate FIRE Conceptual Design ( 12 -15 months duration) 		Dec  04
- 	•  Initiate R&D program in support of FIRE CDA
- 	•  Initiate studies of potential construction sites for FIRE
- • Completion of FIRE Conceptual Design 				Jun  06

## 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
- •  **Physics Validation Review (Jan 2004)**

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

## 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.
-  • We need to take advantage of the interest and opportunity afforded by the ITER initiative.   We also need to broaden interest in fusion, burning plasma physics and  the associated scientific program. This is consistent with the consensus in the U.S. fusion community, FESAC, NRC and Energy Bill.

**Concluding Remarks**