D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 1/16 Molecular Data in Tokamak edge Modelling D....
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Transcript of D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 1/16 Molecular Data in Tokamak edge Modelling D....
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 1/16
Molecular Data in Tokamak edge Modelling
D. Tskhakaya
Association EURATOM-ÖAW, University of Innsbruck, A-6020 Innsbruck, Austria
Andronikashvili Institute of Physics, 0177 Tbilisi, Georgia
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 2/16
Molecular sources
Processes involving molecules
Requirements to the molecular data
Needs for kinetic modeling of the plasma edge
Conclusions
Outline
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 3/16
Molecular sources in the SOL
JET
Plasma-facing components (PFC): chamber walls, divertor plates,
RF antennas, …
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 4/16
Molecular sources in the SOL
„Conventional“ tokamaks
AUG, DEMO (?)
JET, ITER
Tokamaks with liquid walls
C (CFC), Fe, …
W
Be
W
LiGas puffing (e.g. D2)
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 5/16
Molecular sources in the SOLPlasma recycling
Wall
D+ A Wall Surface
C, W : A= D2 (>90%)
Be: ?
Li: R~0For DT operation
A= D2, DT, T2
At low energies isotope effects might be important!
H2+ + H2 H3
+ + H D3+, T3
+, TD2+, DT2
+
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 6/16
Molecular sources in the SOLImpurity sputtering
Wall
B AWall Surface
C (chemical sputtering): B= Dm
A= CnDk
W: ?
Be [Björkas PSI 2012]: B= D
A= BeD (<60%)
A= BeD2 (<40%)For DT operation
A= BeD, BeT, BeD2, BeT2
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 7/16
Molecular sources in the SOLImpurity seeding, etching
N2 , O2 , NO2
Molecules to be taken into the account in fusion plasma edge modeling
D2, DT, T2 ,
BeD, BeT, BeD2, BeT2
N2 , O2 , NO2
CnDmTk
D3+, T3
+, TD2+, DT2
+
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 8/16
Processes in the plasma edge involving molecules
e + M e + M Elastic
e + M e + M* Excitation (electronic, vibrational,
rotational)
e + M 2e + M+ Ionization
e + M e + A + B Dissociation
e + M e + A+ + B Dissociative ionization
e + M+ A + B Dissociative recombination
e + M A- + B Dissociative attachment
A + M A + M Elastic
A + M A + M* Excitation
A+ + M A + M+ Charge exchangeA + M+ A+ + M Charge exchange
A + M A + B + G Dissociation
A- + M A + M + e Electron detachment with moleculeM - molecule (in some excitation/ionization state)
A – molecule, ot atom (in some excitation/ionization state)
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 9/16
Requirements to the data
Fluid, or fluid/kinetic models (e.g. B2-SOLPS, ERO, EIRENE, …)
MAMaxwell-distributed
particle pool
B
Rate coefficients (averaged over initial/final excitation-states) are required
eM
Mnn
VV
VdTVfvvVVvvTR
,,...',,,...',,
Data source: ADAS, …
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 10/16
a
b
c
d
a
b
c
d
e
a
b
,E 211 ,,, EE 32121 ,,,,, EEE
Full kinetic models (PIC/MC)
Requirements to the data
10-4
10-3
10-2
10-1
100
10-3
10-2
10-1
100
101
102
KrsticBIT1
[r]
sin [a.u]
2/sin11ln4
1,2
aE
aE
aEd
Ed
Differential cross-sections
for H++H2 elastic collision
implemented in BIT1 code
Data source: any available
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 11/16
Electron/ion VDFs in the SOL [Tskhakaya CPP 2012]
-2 -1 0 1 2
x 107
10-4
10-3
10-2
10-1
100
f e(v||)
V|| [m/s]
2 mm10 cmOMP
-4 -3 -2 -1 0 1 2 3 4x 105
10-4
10-3
10-2
10-1
100
f i(v)
V [m/s]
OMP
SE 0.1 m
Rate coefficients vs differential CS
OMP
10 cm
SE
The VDFs are strongly(!)
non-Maxwellian during the
ELMs
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 12/16
0 0.01 0.02 0.030
2
4
6
x 1018
x [m]
n [
m-3
]
H2
H H+2
e
H+
Density profiles from the divertor plasma
simulation. Serial PIC/MC code with ~100
of different A&M processes.
Full kinetic models
Massively parallel codes
(such as BIT-N) are able
to simulate few of different
particle species (including
metastables) with
thousands of A&M
processes.
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 13/16
For (kinetic) modelers collection of the appropriate
A&M&S data is the most complicated task!
10-2
10-1
100
101
102
103
10-1
100
101
102
E [eV]
PhelpsJanev
Cross-sections for H2+ + H2 charge-exchange
collision from different sources.
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 14/16
0 100 200 300 4000
20
40
60
80
100
qod
[MW
/m2 ]
e+D+
D
t [µs]0 100 200 300 400
0
20
40
60
80
100
120
140
qod
[MW
/m2 ]
t [µs]
e+D+
D
Power loads to the outer divertor during 0.15 MJ type-I ELM at JET #74380.
a) Constant recycling coefficient RD= 0.99;
b) Energy-dependant recycling coefficient RD(E).
a) b)
Sensitivity of simulation results to the A&M data
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 15/16
EFDA Task Force ITM
Task AMNS
Collection and verification of the Molecular data
Implementation into the corresponding AMNS data structure
in a standardized way
Support of different codes in implementation of
corresponding routines for accessing AMNS data
Status: data structure is ready for implementation of molecular
rate coefficients and differential CS of practically any complexity.
There is a possibility to update the data structure for metastables.
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 16/16
Molecular processes represent important part of predictive
plasma edge modeling
While data for rate coefficients are available, the corresponding
differential CS are hard to find
There is no systematic approach to metastables. How to include
them into the plasma edge models?
Conclusions
Independently of the complexity and format of the provided
validated molecular data, it will be used by us (i.e. modelers)!
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 17/16
Filaments of small and large ELMs at MAST (UK)
63.5 63.55 63.6 63.65 63.70
10
20
30
40
50
qdi
v [M
W/m
2 ]t [s]
10-100 ms
0.1-1 ms
ELMs simulations
D. Tskhakaya ADAC meeting, Cadarache 24.9.2012 18/16D. Tskhakaya PWI TF, JET Culham, 13-15 July 2011
Differential cross-sections
e + H = 2e + H+
,/,/
,2/sin11ln4
1
,1
ln1
11
1
1,
cos,cos,,
00
2
3
0322
0
3
EEEE
E
E
Ed
d
b
EE
aEE
dE
d
Ed
dE
d
dEE
dE
d
dddE
d
sspp
ion
ii
s
ip
spsspspsp
s
ion
ppp
ionss
s
ionsp
s
ion
pss
ion
10-3
10-2
10-1
100
0
0.5
1
1.5
2
2.5
BIT1 Krstic 1998
Angular differential cross sections