Interaction of candidate plasma facing materials with tokamak plasma in COMPASS

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F17%3A00476111" target="_blank" >RIV/61389005:_____/17:00476111 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61389021:_____/17:00476111 RIV/44555601:13440/17:43892905 RIV/00216208:11320/17:10369403

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.jnucmat.2017.06.009" target="_blank" >http://dx.doi.org/10.1016/j.jnucmat.2017.06.009</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jnucmat.2017.06.009" target="_blank" >10.1016/j.jnucmat.2017.06.009</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Interaction of candidate plasma facing materials with tokamak plasma in COMPASS

Popis výsledku v původním jazyce

The interaction of tokamak plasma with several materials considered for the plasma facing components of future fusion devices was studied in a small-size COMPASS tokamak. These included mainly tungsten as the prime candidate and chromium steel as an alternative whose suitability was to be assessed. For the experiments, thin coatings of tungsten, P92 steel and nickel on graphite substrates were prepared by arcdischarge sputtering. The samples were exposed to hydrogen and deuterium plasma discharges in the COMPASS tokamak in two modes: a) short exposure (several discharges) on a manipulator in the proximity of the separatrix, close to the central column, and b) long exposure (several months) at thencentral column, aligned with the other graphite tiles. During the discharges, standard plasma diagnostics were used and a local emission of spectral lines in the visible near ultraviolet regions, corresponding to the material erosion, was monitored. Before and after the plasma exposures, the sample surfaces were observed using scanning electron microscopy, the coatings thickness was measured using Rutherford backscattering spectroscopy, and the concentration profiles of hydrogen and deuterium were measured by elastic recoil detection analysis. The uniformity of the coatings and their thickness was verified before the exposure. After the exposure, no reduction of the thickness was observed, indicating the absence of ‘global’ erosion. Erosion was observed only in isolated spots, and attributed to unipolar arcing. Slightly larger erosion was found onnthe steel coatings compared to the tungsten ones. Incorporation of deuterium in a thin surface layer was observed, in dependence on the exposure mode. Additionally, boron enrichment of the long-exposure samples was observed, as a result of the tokamak chamber boronization

Název v anglickém jazyce

Interaction of candidate plasma facing materials with tokamak plasma in COMPASS

Popis výsledku anglicky

The interaction of tokamak plasma with several materials considered for the plasma facing components of future fusion devices was studied in a small-size COMPASS tokamak. These included mainly tungsten as the prime candidate and chromium steel as an alternative whose suitability was to be assessed. For the experiments, thin coatings of tungsten, P92 steel and nickel on graphite substrates were prepared by arcdischarge sputtering. The samples were exposed to hydrogen and deuterium plasma discharges in the COMPASS tokamak in two modes: a) short exposure (several discharges) on a manipulator in the proximity of the separatrix, close to the central column, and b) long exposure (several months) at thencentral column, aligned with the other graphite tiles. During the discharges, standard plasma diagnostics were used and a local emission of spectral lines in the visible near ultraviolet regions, corresponding to the material erosion, was monitored. Before and after the plasma exposures, the sample surfaces were observed using scanning electron microscopy, the coatings thickness was measured using Rutherford backscattering spectroscopy, and the concentration profiles of hydrogen and deuterium were measured by elastic recoil detection analysis. The uniformity of the coatings and their thickness was verified before the exposure. After the exposure, no reduction of the thickness was observed, indicating the absence of ‘global’ erosion. Erosion was observed only in isolated spots, and attributed to unipolar arcing. Slightly larger erosion was found onnthe steel coatings compared to the tungsten ones. Incorporation of deuterium in a thin surface layer was observed, in dependence on the exposure mode. Additionally, boron enrichment of the long-exposure samples was observed, as a result of the tokamak chamber boronization

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20305 - Nuclear related engineering; (nuclear physics to be 1.3);

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Nuclear Materials

ISSN

0022-3115

e-ISSN

—

Svazek periodika

493

Číslo periodika v rámci svazku

September

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

18

Strana od-do

102-119

Kód UT WoS článku

000408044000013

EID výsledku v databázi Scopus

2-s2.0-85020041707