Long-termFusionVision,Strategy,andRoleM.C.Zarnstorff

PPPL

PresentedtotheNASCommi7eeforaStrategicPlanforUSBurningPlasmaResearch

April11,2018

PerspecFveson:1.  StatusofUSresearchsupporFngburningplasmascience

2.  PPPLplansthatmightstrengthenoraccelerateUSresearchinburningplasmascience

3.  StrategicelementssupporFngalong-termvisionforUSfusionenergyresearchandpromoteleadershipinthefield

BuildingonthetalkbyR.J.HawrylukinAus9n,TX

Outline

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•  StrongparFcipaFoninITERisthebestapproachtodevelopburningplasmaresearch,technology,andunderstanding-  advancetofusionenergyresearch

•  InnovaFonisrequiredtoimprovefusionenergyprospectsinUS-  reducesize,cost,andincreaseefficiency,reliabilityofburningplasma-  examples:liquidmetals,compacttokamaks(ST)andstellarators,HTS,advancedmaterials…-  advancetowardscommercialfusionpower

•  BothprovideopportuniFesforUSleadership

Summary

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•  ITERistheUSfacilityforburningplasmaresearch-  ConstrucFoniswellalong-  Benefitsfromworld-wideeffortandinvestment

•  USparFcipaFoninscienceandtechnologydevelopment-  TrainingofUSpersonnelinallaspects-  SignificantUSleadership

•  ThruITER:jointownershipofresults,IPrights,experFse

--ThescienceandtechnologyfromITERwillinformallmagne9c-confinementapproaches

USBurningPlasmaResearchisCenteredonITER

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•  ITERdesignislargelyfixed,candidateQ=10scenariosidenFfied-  SteadystateQ=5scenarioissFllbeinginvesFgated

•  PPPLleadingUSdiagnosFcdesignanddevelopmentCriFcalforITER’sresearchcapabilityAreaofUSleadership&responsibility,includingportdesign

•  Developvalidatedapproachesforhigh-prioritytopics-  DisrupFonsandrunawayelectronbeams-  Edgeinstability(ELM)suppression-  Power-exhaustwidth

StatusofUSBurningPlasmaResearchAcFviFes

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•  SciDAC-CenterforTokamakTransientSimulaFons(PPPLledcollab.)-  3DsimulaFonoftokamakdisrupFonswithconducFngwall-  DisrupFondynamics,sha7eredpelletmiFgaFon,connecttoengr.

•  SciDAC-SCREAMonrunawayelectronmodeling(PPPLledcollab.)-  Newresults:generaFon&sca7eringbyWhistlerwaves-  AppearstoexplainpuzzlingexperimentalobservaFons-  ITERimplicaFonsnotyetevaluated

•  Deep-learningpre-disrupFontriggerformiFgaFon(Internalfunding)•  Rail-gunlaunchedpelletmiFgaFon,forhotplasmaedge(Internalfunding,withU.Washington)

DisrupFon&RunawayElectronMiFgaFon

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EdgeInstabilityControlWindowUnderstood

715

Locking threshold exceeded

Non-resonant 3D perturbations

Suppression threshold

met

IPEC Prediction of stability Space

Experimental Validation of Model

access to “hidden window”

Prediction of No Locking Window of ELM Suppression Validated in Experiment !

•  BuildingonexperimentsatDIII-DandNSTX

•  ControlofKSTARedge

stabilityusing3-rowsofperturbaFoncoilsatedge

•  Varyamplitudeandtoroidalphaseofmiddlerowsofcoils

•  QuanFtaFvevalidaFon

oftheoreFcalmodelforedgeinstabiliFescontrol

Suppressionthresholdmet

2MA NSTX-U

•  IniFallyunderstoodthruheurisFcdrie-model(PPPL)

•  PredicFonforITER:<1mmheatfluxwidth=>veryhighheatflux

•  XGC1(PPPL)reproducesdata

variaFon,butpredictsturbulencebroadensITER.Isthiscorrect?

•  NSTX-Uwilltestbroadening&miFgaFonbyfluxexpansion

DivertorHeat-Flux

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Powerexhaustwidth(mm)

C-Mod

RangeofNSTX-UprojecFons

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2.AcceleratePreparaFonsforBurningPlasmaScience:IntegratedModeling

IntegraFonFramework

Plasma-MaterialInteracFon

HeaFng&Fueling

Large-scaleInstabiliFes

EnergeFcParFcles

Tight/loosecouplingmethods

Mul$-scale$meadvance

Core model

Edge model

•  HighfidelityintegratedmodelofburningplasmathruDOEExascaleProj.•  IniFalfocus:core-edgeFghtintegraFon,buildingonSciDACmodels

SeetalkbyA.Bha7acharjee

tokamaks&

stellarators

PPPL(lead),ANL,LLNL,ORNL,Rutgers,U.Texas,UC-Boulder

•  Reducedfidelity,faster,integratedmodelsunderdevelopment-  ForpredicFvemodelingofproposedexperiments-  ForrouFneanalysisofdata-  Verifiedwithhigh-fidelitymodels-  Validatedoncurrentexperiments,includingDIII-DandNSTX-U

•  Especiallyimportantforhighpressure(β)andbootstrap-currentforlong-pulseexperiments,duetonon-linearevoluFonofequilibrium

•  SimilareffortsstarFngforstellarators

PreparingProducFonWhole-DeviceModels

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Example:NSTX-Uisstudyingα-parFcleinstabiliFesapplicabletoITER

Conventional Beam-heated tokamaks

α-heatedconventional aspect

ratio tokamaks(ITER, DEMO)

α-heatedSphericalTokamaks

Beam-heatedNSTX-U

0

2

4

6

0.0 0.1 0.2 0.3 0.4 0.5

β fast/β total~ (EP-instability drive)/(EP-instability damping)

NSTX-U: Fast-ion dynamic range spanning ST and conventional A burning plasma regime

Vary beam pitch angle, pressure profile à Assess mode stability as a function of ion phase space

NSTX-U will: •  assess confinement

of fast-ions in high-performance ST regimes

•  extend predictive capabilities for energetic particle dynamics in burning plasma regime

•  ITERisaphysicsandtechnologyexperimentWillprovideknowledge&experienceforfusionenergyresearch

•  Asinthe2004NRCBurningPlasmaReport,ITERisnotaprototypeforacommercialpowerreactorintheUS-  Needhigherperformanceforsizeandcost

•  NextstepsbasedonITERarelargerandlikelymoreexpensive,e.g.EUDEMO

3.Long-termVisiontowardFusionEnergy

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EU DEMOpulsed-ind.

R0 (m) 9.0a (m) 2.5BT (T) 6.5IP (MA) 16.8fBoot 36%β 2.6%H98,y2 1.0Pthermal 2.2 GWNet Pelectic

500 MW

•  Insomecountries,fusionwillbedevelopedbytheirgovernment•  US:developmentofcommercialfusionwillbeledbyindustry-  Roleofgovernmentistoenablebydevelopingunderlyingscience-  Enableviapublic-privatepartnerships

•  Interestbystart-upcompaniesveryimportantSignofsuccessindevelopingscienFficandtechnicalbasisforfusion-  Assessmentthatgapsprobablycanbeclosed-  Buildsonworld-wideexperiments(allkinds)andITER

•  FocusonprioriFzingandresolvingrisks-  Atminimumscale(cost)andonarapidFmescale

USRoutetoCommercialFusion

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IndustryRequests•  Safety•  Long-termeconomicallycompeFFve•  RapidconstrucFonandmoderatecapitalcostperunit•  Licensingsimplicity•  Reliability,availability,maintainability,inspectability(RAMI)•  Steadystate,withload-following(quickshutdown/restart)•  Publicacceptance-  Noneedforwide-areaevacuaFon

Notthesameapproachassomeofourinterna9onalpartners

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AeerEPRI,LIFEAdv.Commi7ee

•  Robust,reliableoperaFon–eliminatedisrupFonsand“offnormalevents”-  ThinfirstwallforT-breeding

•  MoreefficientproducFonofenergyanduseofplant-  Higherfusionpowerdensity=>higherβand/orB-  LessrecirculaFngpower

•  Smallerunitsizethan1GWe,especiallyduringdevelopment

•  Robustpowerhandlingwithreducedmaintenance•  Simplify,probablybyeliminaFonofsomesub-systems

•  Needlong-livedmaterials,toreducemaintenance(esp.divertor)

ImplicaFons:InnovaFonisNeeded

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•  Liquid-metalboundaries(seeM.Jaworski)-  Highpower-flux,eliminateerosion,allowslow-Zwallandhigherconfinement (NSTX-U,EAST?)

•  Sphericaltokamak(seeS.Gerhardt)-  Morecompact,highβ,highermagneFcfielduFlizaFon,lowercapitalcost (NSTX-U&MAST-U)

•  Higherefficiencycurrentdrive-  Helicon-waveandinsidelaunchlower-hybridcurrent-drive(DIII-D&KSTAR)

•  Compactstellarators/3D-Tokamaks(commi7ee’steleconference)-  EliminatedisrupFons,eliminatecurrent-drive;highβ,highdensity,highgain (USled,but?)

InnovaFonOpportuniFes

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•  HTSmagnets(seeM.Greenwald,S.Prestemon)-  HigherB,highercurrentdensity,enablescompactconfiguraFons-  Mayallowsimplercoildesign

•  Advancedmaterials-  Longerlife,higherstrengthathightemperature-  Reducemaintenance,increaseavailability,increasethermalconv.efficiency

•  UsevalidatedsimulaFontoguideextrapolaFon(SeeA.Bha7acharjee)-  Reducerisks

•  Aimata“pilotplant”(seeJ.Menard)-  AddressintegraFonrisksatmodestscale-  ThenmaturetechnologyandoperaFngexperiencetogether-  IfinnovaFonsachievehighQ,net-powerproducFoniseasierthanlife-FmetesFng

PPPLisexploringmanyofthesepoten9alinnova9onswiththecommunity.

InnovaFonOpportuniFesII

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•  DuringITERconstrucFonandburningplasmaoperaFon:-  ExploreandmatureinnovaFons-  A7emptmulF-innovaFonintegraFon,increasingTRL-  ValidatemodelsforsimulaFon

•  AssesscombinedresultsfromITERandinnovaFonsinmodeledprojecFons

•  Goforwardwhenprojectedsystemsarecompelling,andaddresscommercialneeds-  PilotPlantassmallascredible,toreducerisks,buildconfidence

StrategywithITER:InnovateinParallel

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•  USoutofITER:lossoftechnicalexperFse,experience,momentum- MissediteraFonwilldelayUSadvancetoburningplasmaresearch-  RecoverbyexploringandmaturinginnovaFons;integraFng

•  AssessresultsfrominnovaFonscombinedwithworld’sexperimentsinmodeledprojecFons,butwillnothavefullITERknowledge

•  Goforwardwhenprojectedsystemsarecompelling,moFvatefunds-  RecoverburningplasmaexperFseandexperience- MayuseinnovaFonstopartnerwithotherprogramspost-ITER-  PilotPlantassmallascredible,toreducerisks,buildconfidence

StrategywithoutITER:Innovate

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•  StrongparFcipaFoninITERisthebestapproachtodevelopburningplasmaresearch,technology,andunderstanding-  advancetofusionenergyresearch

•  InnovaFonisrequiredtoimprovefusionenergyprospectsinUS-  reducesize,cost,andincreaseefficiency,reliabilityofburningplasma-  examples:liquidmetals,compacttokamaks(ST)andstellarators,HTS,advancedmaterials…-  advancetowardscommercialfusionpower

•  BothprovideopportuniFesforUSleadership

Summary

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