overview of the jet preparation for deuterium-tritium...

Overview of the JET preparation for Deuterium-Tritium Operation with the ITER Like-Wall

E. Joffrin, on behalf of EUROfusion JET contributors Acknowledgments:totheJETTaskForceandProjectLeaders,JETsecondees,EUROfusionProgrammeManagementUnit,JETExploitationUnitandJEToperator

E. Joffrin et al. | 27th IAEA Fusion Energy Conference | Gandhinagar, India| 22-27 Oct. 2018 |

JET is designed for fusion power studies in support of ITER

JET-ILW:PNBI=32MWPICRH=8MW

1975JETdesignproposal:“…describesalargeTokamakexperiment,whichaimstostudyplasmabehaviourinconditionsanddimensionsapproachingthoserequiredinafusionreactor”.

JET iscapableofconfining90%ofalphaparticleforIpabove2.5MA


Objectives and outline

1.   DevelopD-Tscenarioandfusionpowerprediction

2.   Understandisotopephysics

3.   PreparetheoperationinD-T

DTE1in1997-98:M.KeilhackerNucFus39(1999)209&J.JacquinotNucFus39(1999)235

EUROfusionresearchroadmap:Securethesuccessof future ITERoperationviaspecificpreparationandexperiments,includingD-ToperationofJET.

DTE1JET-C(1997)

92436:PFUS-EQJET-ILW(2016)

15MW/5starget

012345678Time(s)

15

10

50

Fusionpower(MW)

EUROfusionMST1taskForce:H.Meyer,OV2-1


Stationary Scenarios for the DT phase achieved ~7-8MW of equivalent PFUS

PNBI (MW) PICRH (MW)

βN

Line integrated density (1019m-2)

PNBI (MW) PICRH (MW)

βN

Line integrated density (1019m-2)

“Hybrid” scenario 2.2MA/2.8T q95~4, βN~2-3 H98(y,2)=1.3

“Baseline” scenario 3.0MA/2.8T q95~3, βN~1.8 H98(y,2)=1.1

Time (s) Time (s)

L.Garzotti,EX/3-6E.DelaLuna,EX/2-1

PFUS(MW)30-35%thermo-nuclear

Fusion equivalent power for a 50/50 D/T mix: 7-8MW of fusion power for both scenarios

PFUS(MW)~60%thermo-nuclear

E. Joffrin et al. | 28th FEC conference | Ghandinaghar | 22-26 Oct. 2018 |

“After-glow” ITB scenario shows promising route for alpha-driven mode studies

50/50D-TPrediction(TRANSP)

n=4

Stabilitycalculation(MISHKA)

R.Dumont,Nuc.Fus.2018S.Sharapov,EX/P1-28

TAEs

After-glow


D-Tequivalentfusionpowerfor2014-2016discharges

q  Equivalent fusion power reaching similar level than in the 1998 D-T campaign (DTE1) with two stationary scenarios: baseline and hybrid.

q  Transient ITB scenario for α-particle driven mode studies

50/50 D/T mix for identical plasma parameters

q  Nocreditforisotopeeffectsq  Nocreditforα-power

Prospects for 10 to 15MW of fusion power in stationary scenarios in JET-ILW

0

2

4

6

8

10

12

14

16

0 5 10 15 20 25

BaselineHybridITB

DTE1ActualPFUSP F

US[M

W]

W[MJ]

D-TEquivalentfusionpowerwith40MW Hot-ion

H-modes

D-T equivalent fusion power


10-16MW of fusion power also predicted in D-T by first principle based modelling

q  Isotope effect from ExB shear stabilisation or energy exchange.

q  Alpha power contribution

q  Auto-consistent modelling with core (BGB)-pedestal (EUROped) with no isotope effects.

Uncertainty in PFUS accounts for different plasma current and bootstrap models

19

15

1173

P FUS(MW)

20304050PIN(MW)

CRONOS-TGFL&JINTRAC-QUALIKIZ:filledsymbolsJINTRAC-BGB-EUROped:opensymbolsCRONOS-CDBM:Stars

Hybrid

BaselineITB

J.Garcia,TH/3-1F.Casson,TH/3-2

S.Saarelma,PPCF2017

Taking into account additional effect:


ICRH power can efficiently control W accumulation in D-T scenario

q  n=1Hminorityè electronheating

q  n=1He3minorityè ionheating

q  Combinationofboth

P RADinside

ρ=0.2(M

W)

CentralTe(keV)

CentralTi(keV)

P.Jacquet,Nucl.Fus.2016D.vanEester,IAEA2016

F.Casson,TH/3-2

43210

7891011Time(s)

Tio=10.7[keV]

Tio=12.7[keV]

Tio=14.2[keV]

ICRHschemesdevelopedforD-T

Firstprinciplepredictionof D-T scenario with40MW&Ti>Te

Ionheatingpredictedtoprovider e s i l i e n c e t o h i g h - Zaccumulation

Demonstratedexperimentally

PICRH(MW)

E.Lerche,Nucl.Fus.2016M.Goniche,PPCF2017


3 ion schemes H-(DNBI)-D: a new development in support of D-T

Y.Kazakov,EX/8-1&Nat.Phys.2017J.Ongena,RFConf.2017

D-T plasmas: optimize Q and fusion power using NBI+ICRH synergies: ET-NBI = 118keV, à <ET> ≈ 200keV (off-axis n = 1 ICRH)

T-NBI+n=1ICRH

T-NBI

Efficient acceleration of NBI ions to higher energies with n = 1 ICRH in mixed plasmas

q  H-D plasmas: increase in neutron rate due to accelerating D-NBI ions to ED ≈ 1-2MeV,

q  Confirmed with TOFOR, γ-ray measurements and ICRH modeling


Understand isotope physics


L-mode: weak positive isotope dependence on confinement & transport

HydrogenDeuterium

-2.5 -2.0 -1.5 -1.0 -0.5τ thlog( ) [experiment]

τ th

log(

)[regressio

n]

-2.5

-2.0

-1.5

-1.0

-0.5

q  Small positive isotope dependence of τth q  Consistent with the H97L scaling τ ~ A0.2

L-modeconfinementscalingwithmass(PINscanatne=cst,Ti~Te;BT=2.9T,Ip=2.5MA)

HydrogenDeuterium

Matchofρ*,β,ν*H/Dpairsatisfiesscaleinvariance(sameωciτEth )

q  Noadditionalisotopedependenceneededq  Agreementachievedwithmodelling for the

identitypairq  Differencewith0Dscalingbeingexamined

τth ~ A0.15±0.02

H.Weisen,EX/P1-4P.Strand,TH/P6-14C.Maggi,PPCF2018

TGLF

3.03.23.43.63.8R(m)

3.03.23.43.63.8R(m)

TGLF


C.Maggi,PPCF2017

L-H power threshold likely to be lower in Tritium for D-T scenario

J.Hillesheim,EX/4-1

q  PL-H threshold likely to be reduced by 2/3 in tritium and 1/3 in D-T. q  Consistent with past DTE1 results (Righi et al. 1999).

Predictionwith non-linearfluid turbulence code(HESEL) reproduces strongdependence:~1/A1.4

Hx2

x2/3

PL-Hthreshold~1/A

2008scaling

D-T

T


Type I ELMy H-mode: strong positive isotope dependence on thermal confinement

q  Stronger isotope dependence than in JET-C and IPB98(y,2) (~A0.2)

q  Global momentum ~ A0.5±0.15

q  Global particle ~ A0.5±0.06

All scalings robust against the set of variables chosen for the regression.

Note: Density systematically lower in H at same external fuelling

Hydrogen

Deuterium

The pedestal is an important player in the observed isotope dependence

τth ~ A0.4±0.1

H-modeconfinementscalingwithmassH:1.0MA/1.0Tand1.4MA/1.7T

D:1.0MA/1.0T,1.4MA/1.7T,1.7MA/1.7T

H.Weisen,EX/P1-4C.Maggi,PPCF2018


Larger pedestal pressure in D than H at same power and gas fuelling rate

IP=1.4MA;BT=1.7T;PIN=10MWELMs;samefuellingrate:19HzinDand31HzinH

q  Isotope effect peeling-ballooning is weak for same separatrix Te.

q  Different separatrix temperature in H and D could change pedestal stability.

q  Inter-ELM particle loss different in H and D. L.Horwarth,Nuc.Fusioninpreparation

Lower density observed in H for equivalent external gas injection rate


Isotope mixing: key particle transport effect for D-T scenario

In typical JET scenario: è Di/De>1 and Vi/Ve>1

R/LT

Important for isotope fuelling & control in JET and ITER.

nDandnHR/Lnsimilarandindependentofthesource.

. ..

è

Di/De

C.BourdelleNucFus2018M.MaslovNucFusion2018

C.Angioni,Phys.Plasmas2018

91232 (1.4MA/1.7T), H/D=0.9


L-modeInter-ELM Intra-ELM

Detachment

BeàW

TàBe

DàBeHàBe

TàW

DàWHàWPh

ysicalsp

utterin

gyields

Be and W physical sputtering will increase with Tritium

Frombinarycollisionapproximation(SDTtrimSPcode)

The increase of Be physical sputtering by tritium can lead to an increase of W sputtering by Be

IncreaseofWsputteringyields and thresholdenergy by tritium inintra-ELMphase.

IncreaseofBesputteringbytritiumininter-ELMphase

D.Borodin,EX/P1-14S.Brezinsek,EX/9-4


Intra-ELM sputtering will dominate W sputtering in tritium

A.KirschnerPPCF2018

SyntheticimageERO2.0

Tungsten erosion with isotope Be erosion

T

D

H(Analyticalmodel)

Intra-ELM: ~70% of the gross-erosion

J.Romazanov,PSI2018

Borodkina,Nuc.Mater.Energy2017

From post-mortem analysis in D: Ø  W gross erosion: 40-60 g Ø  W net erosion: 2.4-4.8 g Ø  90% of prompt redeposition

(Deuterium)


Decrease of material deposition rate by x4-9 compared to JET-C

A.Widdowson,Phys.Script.2018M.Mayer,EX/P1/15

Be:71019atoms/cm2

D:41018atoms/cm2

C:31018atoms/cm2

O:1019atoms/cm2

N:51018atoms/cm2

Since 2011, operation with JET-ILW: 60h of plasma and 600MJ of input energy

Be:21019atoms/cm2

D:21018atoms/cm2

C:21018atoms/cm2

O:1019atoms/cm2

Be:41019atoms/cm2

D:21018atoms/cm2

C:51018atoms/cm2

O:51018atoms/cm2

N:51018atoms/cm2

Dominantstrikepointposition

5

4 6

q  Deuterium retention decreased by afactorof10to20wrttoJET-C.

q  The retention of tritium in deposits isnot expected to be significantlydifferentthandeuterium.

Cryo-pump


Prepare the operation in D-T


Upgrades for D-T: NBI and T injection

5newtritiumgasinjectionmodules,(OnlyoneexistinginDTE1)

I.Carvalho,29thSOFT2016

MaximumNBIpowersofarlimitedbyoneofiondumpscomponentcoolingcapabilities.

Newplateswithoptimisedcoolingremovingthe limits tobeamvoltageandpulse lengthè34MWinD-T(21MWinDTE1)

A.Shepherd,29thSOFT2016

Beaminjectors

DD

T

D

T T T

D

D

D

D

TD


Unique set of new diagnostics in place for alpha physics and burning plasma studies in DTE2

J.Figueiredo,EX/P7-42S.Sharapov,EX/P1-28

Visualization of fast particle orbits with γ-ray tomography

SeveralburningplasmadiagnosticsreadyfortheD-Tphase.

ChargeExchange(Ti)

TAEantenna

NeutronCamera

VerticalNeutronSpectrometer

γ-RayCamera

Horizontalγ-RaySpectrometerforalpha-ParticleDiagnostic UpgradeofthescintillatorbasedFast-IonLossDetector(FILD)

Mostdiagnosticsincludedsyntheticallyinmodellingsuitesforcodevalidation


40m

Newmirrors

New tools developed for burning plasma

V.Huber,EX/P1-31

Isotoperatiocontrolledat50%inH-mode

Infra-redprotectioncameramovedoutsidethebiologicalshield

M.Lennholm&D.Valcarcel,FED2017

BothtechniqueswillbeessentialforITERD-Toperations

Camera

Pulse91234(1.4MA,1.7T)

PNBI(MW)

Isotopicratio(vis.Spec.)

D

H

Time(s)


q  14MeV neutron generator deployed inside JET vessel by remote handling §  76h of irradiation in 73 different

poloidal and toroidal positions §  Calibration within ±6%

q  Neutronic modelling carried out and codes validated for ITER.

è Procedure transferable to ITER.

14MeV neutron detector for the D-T phase calibrated with an accuracy of ±6%.

3 Fission (235U) chambers and 1 Activation system

P.Batistoni,NucFus2018,E.Laszynska,SOFT2018,

T.Vasilopoulou,SOFT2018,S.R.Villari,SOFT2018


Tritium operation with JET-ILW: x5 more neutron budget than in DTE1

E.Belonohy,SOFT2016

DTE1 TT

Neutron 3.1020 0.11021

Tritiuminjected 35g ~300g

Strict accounting of tritiumused <11g in cryo panelsregeneratedeveryday

Restricted access toarea where neutrona c t i va t i on and γradiationcanbehigh.

Plasma operation rehearsal planned during the D campaign

T: 60g for

DTE2

DTE2

1.551021

~150g


Highlights of the preparation for D-T

q  Existing D-T scenarios have reached 7-8MW/2.5s equivalent fusion power and can attain 10 to 16MW of fusion power with 40MW of input power in the JET ITER-like wall

q  After-glow ITB scenario is a credible route for alpha particle driven instabilities study and code validation for ITER

q  Confinement and particle transport show strong positive isotope dependences and is also investigated for ITER conditions

q  Tritium will modify the SOL conditions and plasma surface interactions significantly but retention is expected to stay low

q  JET has developed a comprehensive set of diagnostics, tools and procedures in support of ITER burning plasma operation


Next JET timeline and Prospects

D-T campaign Ø  15 MW of fusion power for 5s

in stationary conditions Ø Study of alpha physics

H & T Ø  Isotope campaigns

Shattered Pellet Iinjector

D campaign Ø  D-T scenario preparation Ø  Disruption/RE studies


Thank you for your attention on behalf of the EUROfusion JET contributors

overview of the jet preparation for deuterium-tritium...

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