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Max-Planck-Institut für Plasmaphysik, EURATOM
Association
Kinetic Modeling of Edge Plasmas
Konstantin Matyash
Ph. D. work at Max-Planck IPP, Stellarator theory
division, Edge Modeling Group since June 13, 2000
Scientific supervisors
Dr. Ralf Schneider
Dr. Wolfgang Jacob
Academic Supervisor
Prof. Dr. Jürgen Nührenberg
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association Motivation
Carbon deposition in divertor regions of JET and
ASDEX UPGRADE
Major topics tritium codeposition
chemical erosion
JET
Paul Coad (JET)
ASDEX UPGRADE
Achim von Keudell (IPP, Garching)
V. Rohde (IPP, Garching)
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association Experimental setup
PLATO device
fHF 2.45 GHz
PHF 10 - 400 W
Bres 87.5 mT
GCH4 1017 -1019 s-1
Ne 109 -1011 cm-3
Ei 1 - 25 eV
Model system for the study of chemical erosion
and deposition of carbon layers.
Deposition of diamond-like carbon films in
plasma technology devices
Wolfgang Jacob (IPP, Garching)
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association Rate equations
Solution of 0-D dynamic particle balance
(rate equations)
174 reactions between 14 neutral and 13 ion
species C2H6, C2H5, C2H4, C2H3, C2H2, C2H, C2,
CH4, CH3, CH2, CH, C, H2, H and C2H5, C2H4,
C2H3, C2H2, C2H, CH4, CH3, CH2, CH, C,
H2, H
ne 1010 cm-3 p 1.25 Pa Te 3.2 eV Ti,n
450 K GCH4 2.31015 cm-3s-1
Experimental points from P.Pecher IPP-Report,
9/118 1998
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association Particle in Cell simulation
Development and application of 2DX3DV PICMCC
multispecies code
Achievements
generalization for multispecies addition of
neutrals addition of all necessary collisions
ECR heating model with feed-back control loop
simple plasma-surface interaction model
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association Particle in Cell simulation
Binary Coulomb collisions model
Scheme explicitly conserves particles, energy
and momentum
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association
Reactions included in the model
e- CH4 ? CH4 2e- e- CH3 ? CH3 2e- e-
CH2 ? CH2 2e- e- CH ? CH 2e- e- CH4
? CH3 H 2e- e- CH3 ? CH2 H 2e- e-
CH2 ? CH H 2e- e- CH ? C H 2e- e-
CH ? C H 2e- e- CH4 ? CH3 H e- e-
CH3 ? CH2 H e- e- CH2 ? CH H e- e-
CH ? C H e- e- CH4 ? CH3 H e- e-
CH4 ? CH3 H e- e- CH3 ? CH2 H e-

e- CH3 ? CH2 H e- e- CH2 ? CH H
e- e- CH2 ? CH H e- e- CH ? C H
e- e- CH ? C H e- e- CH4 ? CH3
H e- CH4 ? CH2 2H e- CH3 ? CH2 H e-
CH2 ? CH H e- CH ? C H e- C ? C
2e- H CH4 ? CH4 H H CH3 ? CH3 H H
CH2 ? CH2 H H CH ? CH H H C ? C
H
e- H2 ? H2 2e- e- H2 ? H H e- e- H
? H 2e-
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plato-like
Potential profile
ne 1010 cm-3 nn 1014 cm-3 PHF 0.01
W/cm3 Bmin / Bmax 0.5
CH4, CH3, CH2, CH, C, H, CH4, CH3, CH2, CH,
C, H2, H, H2, e- Wall recycling
typical calculation speed 2.5105 time steps
(10-5 s) per day on 32-processor Linux cluster
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plato-like
Electron temperatures anisotropy
parallel electron temperature
perpendicular electron temperature
Target wall
Target wall
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plato-like
CH4 density
electron density
Target wall
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plato-like
Ion energy distributions at the target surface
calculated
measured
Experimental data from P.Pecher IPP-Report,
9/118 1998
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plato-like
Feedback in action
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation RF capacitive
discharge
Collaboration with IEP5, Bochum University
(Ivonne Möller)
ne 109-1010 cm-3 nn 1.51016 cm-3 fRF 13.56
MHz
potential
electron density
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation RF capacitive
discharge
ne 1010 cm-3, nH2 1.31015 cm-3 , nCH4
1015 cm-3 , p 0.17 Torr
ne 1010 cm-3, nH2 1.31015 cm-3 , nCH4
1015 cm-3 , p 0.17 Torr
Stochastic (Fermi) heating
Ohmic heating
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation plasma created by
photons
ASDEX Upgrade, experiment V. Rohde et al.
Modeling with methane plasma
Both photoionisation and photoeffect are
included in model
Plasma detected below roof baffle of Div IIb
Typical parameters 4108 lt ne lt 71011 cm-3 5
lt Te lt 15 eV Scaling ne
Radiation2.7Particles_flux0.7 Plasma
originated by photoionisation or photoeffect !
Simulations have shown the possibility of
sustaining the low temperature plasma with a
flux of photons
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal (2D)
Lower half-domain
Dust particle as additional species q 104e R
10-6 m M 10-10 g
Supersonic ion flow
Lower electrode
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal (2D)
Potential
Potential determined by sheath and dust
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal (2D)
Potential
Vertical ion velocity
Wake field effects due to ion flow
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal (2D)
Vertical ion velocity
Ion density
Focusing of the ion flow, dust molecules
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal (2D)
Vertical ion velocity
Horizontal ion velocity
Focusing of the ion flow
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal (2D)
Vertical electric field
Horizontal electric field
Vertical electric field is responsible for
levitation force
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal (2D)
Averaged vertical electric field
Averaged horizontal electric field
No net horizontal force
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal (2D)
Vertical electron temperature
Horizontal electron temperature
Stochastic heating of electrons in the dust layer
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal - full
3D!
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal, zero
gravity
2D case
3D case
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association Conclusion
SUMMARY

• the numerical instrument (full 3D electrostatic
  PICMCC code) for full kinetic modeling of
  multispecies plasma is developed and tested

Plato 0D chemical kinetic model, B2-Eirene
fluid model SOL-like case HF capacitive
discharge Photon created plasma Plasma crystal
FUTURE PLAN

• eventually extend to electromagnetic case
  (helicon discharge)

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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal, zero
gravity
Potential
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal, zero
gravity
Potential
Horizontal ion velocity
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal, zero
gravity
Horizontal ion velocity
Ion density
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal, zero
gravity
Vertical electric field
Horizontal electric field
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal, zero
gravity
Averaged vertical electric field
Averaged horizontal electric field
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Max-Planck-Institut für Plasmaphysik, EURATOM
Association PIC simulation Plasma crystal, zero
gravity
Vertical electron temperature
Horizontal electron temperature