Počet záznamů: 1
Simulations of thermionic suppression during tungsten transient melting experiments
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SYSNO ASEP 0482343 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Simulations of thermionic suppression during tungsten transient melting experiments Tvůrce(i) Komm, Michael (UFP-V) RID, ORCID
Tolias, P. (SE)
Ratynskaia, S. (SE)
Dejarnac, Renaud (UFP-V) RID, ORCID
Gunn, J. P. (FR)
Krieger, K. (DE)
Podolník, Aleš (UFP-V) ORCID
Pitts, R.A. (FR)
Pánek, Radomír (UFP-V) RIDČíslo článku 014069 Zdroj.dok. Physica Scripta. - : Institute of Physics Publishing - ISSN 0031-8949
T170, December (2017)Poč.str. 5 s. Forma vydání Tištěná - P Akce PFMC 2017: 16th International Conference on Plasma-Facing Materials and Components for Fusion Applications Datum konání 16.05.2017 - 19.05.2017 Místo konání Düsseldorf Země DE - Německo Typ akce WRD Jazyk dok. eng - angličtina Země vyd. SE - Švédsko Klíč. slova tokamak ; thermionic emission ; tungsten ; melt ; plasma-facing component Vědní obor RIV BL - Fyzika plazmatu a výboje v plynech Obor OECD 1.3 Physical sciences CEP GA16-14228S GA ČR - Grantová agentura ČR 8D15001 GA MŠMT - Ministerstvo školství, mládeže a tělovýchovy Institucionální podpora UFP-V - RVO:61389021 UT WOS 000417694700014 DOI 10.1088/1402-4896/aa9209 Anotace Plasma-facing components receive enormous heat fluxes under steady state and especially during transient conditions that can even lead to tungsten (W) melting. Under these conditions, the unimpeded thermionic current density emitted from the W surfaces can exceed the incident plasma current densities by several orders of magnitude triggering a replacement current which drives melt layer motion via the J x B force. However, in tokamaks, the thermionic current is suppressed by space-charge effects and prompt re-deposition due to gyro-rotation. We present comprehensive results of particle-in-cell modelling using the 2D3V code SPICE2 for the thermionic emissive sheath of tungsten. Simulations have been performed for various surface temperatures and selected inclinations of the magnetic field corresponding to the leading edge and sloped exposures. The surface temperature dependence of the escaping thermionic current and its limiting value are determined for various plasma parameters, for the leading edge geometry, the results agree remarkably well with the Takamura analytical model. For the sloped geometry, the limiting value is observed to be proportional to the thermal electron current and a simple analytical expression is proposed that accurately reproduces the numerical results. Pracoviště Ústav fyziky plazmatu Kontakt Vladimíra Kebza, kebza@ipp.cas.cz, Tel.: 266 052 975 Rok sběru 2018
Počet záznamů: 1