Speaker
Liga Avotina
(Institute of Chemical Physics)
Description
Tungsten covered carbon materials due to good thermal conductivity of carbon based materials (up to ~250 Wm-1-1K-1 -1 for carbon fiber composites [1]) are suitable for use in fusion devices, like ITER (International Thermonuclear Experimental Reactor) [2], as divertor materials. However, during the plasma wall interactions, erosion and re-deposition, as well as formation of redeposited coatings on the plasma facing surfaces leads to retention and accumulation of fusion fuel, including tritium in the deposited layers and bulk of materials, causes shortening the lifetime of materials and modifications of the their properties. In order to estimate forms of compounds created during plasma-wall interactions in fusion reactors, it is important to understand processes taking place during high energy influence to divertor materials.
Understanding of the induced modification mechanisms taking place during irradiation will allow to better estimate ways of tritium accumulation and formation of dust and flakes in fusion reactor,
In order to simulate effects of the high energy (up to several GW/cm-2-2) fluxes possible in the tokamak reactors, prototype deposited coatings created by Thermionic Vacuum Arc technique (TVA) were irradiated with single and multiple fs laser pulses
Changes in beryllium crystalline structure as well as in graphite crystallite sizes and amount of sp33 hybridized carbon were observed during single and multiple laser pulses. Laser irradiation induces surface structural and morphological changes by ripples formations.
Laser and plasma affected zones were characterized by Raman and Fourier transformation infrared (FT-IR) and X-ray fluorescence spectroscopy, as well as with SEM and EDX analysis and some interpretations of the induced modification mechanisms are presented.
Acknowledgments
This work was supported by a grant of the Romanian National Authority for Scientific Research, CNCS-UEFISCDI, project number PN-II-IDPCE-2011-3-0522.
References
1.J.P.Bonal, C.H.Wu/Journal of Nuclear Materials 228(1996)155-161
2.V.Riccardo et al./Fusion Engineering and Design 89(2014)1059-1063
Co-authors
Aleksandrs Petjukevics
(University of Daugavpils, Parades Str.1, LV 5401, Daugavpils, Latvia)
Aurelian Marcu
(National Institute for Laser, Plasma and Radiation Physics, Atomistilor Str. 409, 077125, Magurele, Romania)
Catalin Luculescu
(National Institute for Laser, Plasma and Radiation Physics, Atomistilor Str. 409, 077125, Magurele, Romania)
Constantin Paul Ganea
(National Institute of Materials Physics , Atomistilor Str. 105 bis, 077125, Magurele, Romania)
Corneliu Porosnicu
(National Institute for Laser, Plasma and Radiation Physics, Atomistilor Str. 409, 077125, Magurele, Romania)
Cristian Petrica Lungu
(National Institute for Laser, Plasma and Radiation Physics, Atomistilor Str. 409, 077125, Magurele, Romania)
Gunta Kizane
(Institute of Chemical Physics, University of Latvia, Jelgavas Str.1, LV 1004, Riga, Latvia)
Liga Avotina
(Institute of Chemical Physics, University of Latvia, Jelgavas Str.1, LV 1004, Riga, Latvia;National Institute for Laser, Plasma and Radiation Physics, Atomistilor Str. 409, 077125, Magurele, Romania;Faculty of Physics, University of Bucharest, Atomistilor Str. 405, 077125, Magurele, Romania)
Mihail Lungu
(Faculty of Physics, University of Bucharest, Atomistilor Str. 405, 077125, Magurele, Romania;National Institute of Materials Physics , Atomistilor Str. 105 bis, 077125, Magurele, Romania)
Stefan Antohe
(Faculty of Physics, University of Bucharest, Atomistilor Str. 405, 077125, Magurele, Romania;Academy of Romanian Scientists, Splaiul Independentei 54, 050094, Bucharest, Romania)
