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Need for atomic and molecular data for kinetic modelling of the plasma edge David TskhakayaPowerPoint Presentation

Need for atomic and molecular data for kinetic modelling of the plasma edge David Tskhakaya

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Need for atomic and molecular data for kinetic modelling of the plasma edge David Tskhakaya

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Need for atomic and molecular data for kinetic modelling of the plasma edge David Tskhakaya

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Need for atomic and molecular data

for kinetic modelling of the plasma edge

David Tskhakaya

Association EURATOM-ÖAW, University of Innsbruck, Austria

*Permanent address: Andronikashvili Institute of Physics, Tbilisi, Georgia

History of kinetic plasma simulations including AMP

Vlasov codes

Batischev, et al., J. Plasma Phys. 1999Fusion nonlinear

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Devaux, et al., Phys. Plasm. 2009Fusion linear (BGK)

PIC codes

Birdsall IEEE Trans. Plasma Sci. 1991 ----- linear

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Tskhakaya et al., Europhys. Conf. Abstr. 2002Fusion linear

Matyash et al., J. Nucl. Mater. 2003Low temp. nonlinear

Taccogna et al., J. Nucl. Mater. 2007Fusion nonlinear

Tskhakaya et al., J. Nucl. Mater. 2007Fusion nonlinearHPC (2009)

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D.Tskhakaya, 14th ADAS workshop, Rigberg Castle 5.10.2009

Collision operators for PIC/MC

Choosing of collision pares

Binary collision model

Collision of particles

Examples from BIT1 code (Tskhakaya CPP 2008)

H + H+ = H+ + H

2e + H+ = e + H

e + H = 2e + H+

e + H2 = 2e + H + H+

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D.Tskhakaya, 14th ADAS workshop, Rigberg Castle 5.10.2009

Differential cross-sections: examples

e + H = 2e + H+

Angular differential cross sections

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D.Tskhakaya, 14th ADAS workshop, Rigberg Castle 5.10.2009

How do we implement the AMD

- Search for AMD
- Comparison of the data from different sources
- Direct implementation of the data

Analytic fit functions

Data tables

Computer representation

Cross-sections for H2+ + H2 charge-exchange collision from different sources.

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D.Tskhakaya, 14th ADAS workshop, Rigberg Castle 5.10.2009

The AMD for major processes

We need the differential cross-sections and not rate coefficients!

The best available data: processes involving e, H, H2

Still, there is a poor data for

- Electron three-body recombination
- Isotope-resolved reactions (H, D, T)
- Negative ions H- and H3+
- H2 detachment

Poor data for impurity

- e + C(n)* colisions
- e + W(n), e + Be(n) collisions (?)
- reactions with CxHy

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D.Tskhakaya, 14th ADAS workshop, Rigberg Castle 5.10.2009

Our contribution to AMD

Dedicated low temperature plasma experiments and corresponding kinetic simulations allow to „fine tune“ the available AMD and even propose existence of new processes (Bronold, J. Phys. D 2007 ; Matyash J. Phys. D 2007)

Double emissive layer from oxygen plasma experiment and corresponding PIC simulation. A new dissociative excitation collision O2 + O2+ = O(3p3P) + X is responsible for the emission at x~0.

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D.Tskhakaya, 14th ADAS workshop, Rigberg Castle 5.10.2009

Conclusions

- Present day PIC/MC codes incorporate complex plasma-neutral interaction models, conserving momentum and energy.
- The number of implemented processes is limited mainly by the available AMD. The advanced codes accept any format for the AMD.
- There is a deficit of differential cross-sections even for the major processes, such as isotope-resolved H plasma-neutral and plasma-impurity (C, Be, W,...) interaction.
- How to tackle reactions with Hydrocarbons?
Thank you for your attention!

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D.Tskhakaya, 14th ADAS workshop, Rigberg Castle 5.10.2009