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Accueil > Séminaires et conférences > Séminaires, soutenances de thèses et HDR précédents > 2011 > Séminaires 2011 > Vendredi 17 juin à 10h

Vendredi 17 juin à 10h

Yevgeny Raitses - Plasma-wall interaction in the presence of electron emission

Vendredi 17 juin 2011 à 10h, salle de réunion du CPHT - Ecole Polytechnique

Yevgeny Raitses - Princeton Plasma Physics Laboratory
Email : yraitses pppl.gov
Web : http://htx.pppl.gov

The low pressure laboratory and technological plasmas are always bounded with walls. The electron flux to the wall is determined by the electron velocity distribution function (EVDF) and by the sheath potential, which are consistent with the wall properties. The plasma-wall interaction in the presence of secondary electron or thermionic emission from the wall has been studied theoretically and experimentally both as a basic phenomenon and in relation to numerous plasma applications such as, for example, magnetic fusion devices, various gas discharges and dusty plasmas, Langmuir probes and plasma thrusters. The electron emission from the wall reduces the potential drop in the sheath between the plasma and the wall and, thereby, weakens electrical and thermal insulating properties of the sheath. Beginning with these basic ideas for strong effects of the electron emission in the plasma with Maxwellian EVDF, this talk will discuss more complex situations for collisionless and magnetized plasmas.1 Under such conditions, electron kinetic effects can substantially alter the plasma-wall interaction and change transport properties of the magnetized plasma.2,3 This situation can be relevant to various cross-field discharge devices such as Hall thrusters, magnetic mirrors and advanced divertors of tokamaks.


References

1 I. Kaganovich, Y. Raitses, D. Sydorenko, and A. Smolyakov, “Kinetic effects in a Hall thruster discharge,” Phys. Plasmas 14, 057104 (2007)

2 D. Sydorenko, I. Kaganovich, Y. Raitses, and A. Smolyakov, “Breakdown of a space charge limited regime of a sheath in a weakly collisional plasma bounded by walls with secondary electron emission,” Phys. Rev. Lett. 103, 145004 (2009)

3 Y. Raitses, I. D. Kaganovich, A. Khrabrov, D. Sydorenko, N. J. Fisch, and A. Smolyakov, “ Effect of Secondary Electron Emission on Electron Cross-Field Current in E × B Discharges”, IEEE Trans. Plasma Sci. (2011)


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Tutelles : CNRS Ecole Polytechnique Sorbonne Université Université Paris Sud Observatoire de Paris Convention : CEA
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Directeur de la publication : Pascal Chabert (Directeur)