Infra-red thermography estimate of deposited heat load dynamics on the lower tungsten divertor of WEST

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F20%3A00531671" target="_blank" >RIV/61389021:_____/20:00531671 - isvavai.cz</a>

Výsledek na webu

<a href="https://iopscience.iop.org/article/10.1088/1402-4896/ab4e3d" target="_blank" >https://iopscience.iop.org/article/10.1088/1402-4896/ab4e3d</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1402-4896/ab4e3d" target="_blank" >10.1088/1402-4896/ab4e3d</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Infra-red thermography estimate of deposited heat load dynamics on the lower tungsten divertor of WEST

Popis výsledku v původním jazyce

A thermography inversion algorithm (TEDDY) was developed for the physical exploitation of WEST infra-red thermography (at 3.9 μm) of uncooled graphite tiles coated with 12 μm of tungsten, located at the lower divertor. The numerical scheme features a conservative finite volume approach with the full temperature non linearity of thermal properties of material composing the tile. The inversion algorithm is validated against synthetic test cases built from standardized software. A first in situ quantification of tungsten surface emissivity and reflected luminance along an outer target coated tile is then detailed. This method relies on a comparison of thermography data with absolute temperature measurements from embedded thermal sensors. Low surface emissivity ( ≈ 0.05) is estimated in the common outer strike point area, while increasing to about 0.1-0.15 far from it, possibly due to deposited impurity layers. The heat flux inversion from corrected thermography temperature is illustrated on an L-mode plasma heated with 4 MW of input power, featuring a strike point sweeping of 30 mm along the divertor tile. Power balance and sweeping dynamics are consistently recovered by the heat flux inversion, while the radial profile of parallel heat flux remapped to outer midplane features a Gaussian-exponential shape common to diverted configurations in low dissipation divertor regime.

Název v anglickém jazyce

Infra-red thermography estimate of deposited heat load dynamics on the lower tungsten divertor of WEST

Popis výsledku anglicky

A thermography inversion algorithm (TEDDY) was developed for the physical exploitation of WEST infra-red thermography (at 3.9 μm) of uncooled graphite tiles coated with 12 μm of tungsten, located at the lower divertor. The numerical scheme features a conservative finite volume approach with the full temperature non linearity of thermal properties of material composing the tile. The inversion algorithm is validated against synthetic test cases built from standardized software. A first in situ quantification of tungsten surface emissivity and reflected luminance along an outer target coated tile is then detailed. This method relies on a comparison of thermography data with absolute temperature measurements from embedded thermal sensors. Low surface emissivity ( ≈ 0.05) is estimated in the common outer strike point area, while increasing to about 0.1-0.15 far from it, possibly due to deposited impurity layers. The heat flux inversion from corrected thermography temperature is illustrated on an L-mode plasma heated with 4 MW of input power, featuring a strike point sweeping of 30 mm along the divertor tile. Power balance and sweeping dynamics are consistently recovered by the heat flux inversion, while the radial profile of parallel heat flux remapped to outer midplane features a Gaussian-exponential shape common to diverted configurations in low dissipation divertor regime.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Physica Scripta

ISSN

0031-8949

e-ISSN

—

Svazek periodika

T171

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

SE - Švédské království

Počet stran výsledku

8

Strana od-do

014046

Kód UT WoS článku

000520000600046

EID výsledku v databázi Scopus

2-s2.0-85084674772