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Physics Aspects of the Dynamic Ergodic Divertor(DED)
FINKEN K. Heinz1, KOBAYASHI Masahiro1,2,
ABDULLAEV S. Sadrilla1, JAKUBOWSKI Marcin1,3
1Institut für Plasmaphysik, Forschungszentrum Jülich GmbH, EURATOM

Association,
D-52425 Jülich, Germany, Partner in the Trilateral Euregio Cluster
2Department of Energy Engineering and Science, Nagoya University, Nagoya,Japan
3University of Opole, Institute of Physics, Opole, Poland

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

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OutlineMotivation, aimsExperimental set-up
Ergodic zone
Laminar zone
Dynamic Aspect

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

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Motivation:• The next fusion device (ITER) will have a fusion
power of about 1.5 GW• ===>

300 MW α-particle heating• This power goes to divertor plates, if plasma edge is
not radiatively cooled• Assuming a divertor length of 30 m and a strike
point width of 2 x 4 cm ==>power density of
12.5 kW/cm2• For these power fluxes, no technical solutions areknownInstitut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

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Hot Plasma Core
Magnetic Field

Magnetic Field

Hot Plasma Core
Heat Flux

Heat Flux
Radiating Belt
(SeededImpurities)

Peak Load
Scrape-off Layer
Wall

Pump Limiter
He

Plasma Edge Radiation: too low
Limiter Heat Load: excessive

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

Peak Load
Scrape-off Layer
Wall

Pump Limiter
He

Plasma Edge
Radiation:dominating
Limiter Heat Load: tolerable

Trilateral Euregio Cluster

TECSet-up• 4 quartets of perturbation coils plus two compensationcoils• 4 Phases===> Rotation of perturbation field• f: DC, 50 Hz, band 1 kHz - 10 kHz• Arrangement at HFS with continuous winding in vessel• Maximum perturbation current: 15 kA• Resonance: q(rres) = 3; rres = 0.43 ... 0.46 m (a=0.46 m)• Base modes: m/n = 12/4; 6/2; 3/1 and mixture of 12/4 +6/2
Set-upInstitut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

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TECFinal coil design

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

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Wide angle view in TEXTOR

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

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DED - Spulenkühlung
Wasserkühlung
isolierte
Kupferleiter

Konditionierungbei 250 °C
He auspumpen

Temperaturhub: 110 °C → 250 °C
Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

Heliumgas

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Scientific aims for DED program

DC-operation• Comparison to other ergodization experiments• Optimisation of the radiation belt• Optimisation of particle exhaust• Investigation of a helical divertor
Low frequency operation:• Smearing out of local peaks of heat flux

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

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1 kHz - 10 kHz operation• Smearing out of local heat fluxes• Generation of temporal ergodization• Generation of a differential plasma rotation•

Improvement of plasma confinement•

Delay of disruption limit• Plasma compression in front of pump limiter

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum JülichTrilateral Euregio Cluster

TEC

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

Trilateral Euregio Cluster

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r=0.5 mDED

ALT-II

r=0.4 mΘ = 360°

30 % perturbation current

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

Θ = 0°

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r=0.5 mDED

ALT-II

r=0.4 mΘ = 360°

100 % perturbation current

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

Θ = 0°

Trilateral Euregio Cluster

TEC

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

Trilateral Euregio Cluster

TEC

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

Trilateral Euregio Cluster

TEC

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

Trilateral Euregio Cluster

TECx 10 -6645343212
100.43

0.44

r [m]

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

0.45

0.46

Trilateral Euregio Cluster

TEC

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

Trilateral Euregio ClusterTEC

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

Trilateral Euregio Cluster

TEC

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

Trilateral Euregio Cluster

TEC

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

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area
1

area
2

rres

rres + εInstitut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

area
3

area
4

rcoilrTrilateral Euregio Cluster

TECresistive width: 2.5 cm; m=20
1e+00

Amplitude

1e-01

1e-02
1 kHz
2 kHz5 kHz
10 kHz

1e-03

1e-04
0.38

0.42

0.46
0.5
radius (m)Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

0.54

0.58

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Torque (Nm)1001010.010.1
1Frequency (kHz)Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich

10100

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Summary
The DED-coils are continuous helical windings located at the HFS
inside the vessel.
The Dynamic ergodic divertor will most likely provide a sufficient
ergodization level at the plasma edge.
A laminar zone will form the main contact region with the wall; a2D and 3D modeling was successful.
The field rotation imposes a torque at the plasma edge which isprobably sufficient for generating a differential plasma rotation.
The differential rotation may lead to a suppression of turbulence andan improvement of the confinement; locked modes should beacceterated again.

Institut für Plasmaphysik
Assoziation EURATOM-Forschungszentrum Jülich