Heat loads on poloidal and toroidal edges of castellated plasma-facing components in COMPASS

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F18%3A10379287" target="_blank" >RIV/00216208:11320/18:10379287 - isvavai.cz</a>

Alternative codes found

RIV/61389021:_____/18:00489810

Result on the web

<a href="https://doi.org/10.1088/1741-4326/aab973" target="_blank" >https://doi.org/10.1088/1741-4326/aab973</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1741-4326/aab973" target="_blank" >10.1088/1741-4326/aab973</a>

Result language

angličtina

Original language name

Heat loads on poloidal and toroidal edges of castellated plasma-facing components in COMPASS

Original language description

Dedicated experiments have been performed in the COMPASS tokamak to thoroughly study the power deposition processes occurring on poloidal and toroidal edges of castellated plasma-facing components in tokamaks during steady-state L-mode conditions. Surface temperatures measured by a high resolution infra-red camera are compared with reconstructed synthetic data from a 2D thermal model using heat flux profiles derived from both the optical approximation and 2D particle-in-cell (PIC) simulations. In the case of poloidal leading edges, when the contribution from local radiation is taken into account, the parallel heat flux deduced from unperturbed, upstream measurements is fully consistent with the observed temperature increase at the leading edges of various heights, respecting power balance assuming simple projection of the parallel flux density. Smoothing of the heat flux deposition profile due to finite ion Larmor radius predicted by the PIC simulations is found to be weak and the power deposition on misaligned poloidal edges is better described by the optical approximation. This is consistent with an electron-dominated regime associated with a non-ambipolar parallel current flow. In the case of toroidal gap edges, the different contributions of the total incoming flux along the gap have been observed experimentally for the first time. They confirm the results of recent numerical studies performed for ITER showing that in specific cases the heat deposition does not necessarily follow the optical approximation. Indeed, ions can spiral onto the magnetically shadowed toroidal edge. Particle-in-cell simulations emphasize again the role played by local non-ambipolarity in the deposition pattern.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2018

Confidentiality

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

Name of the periodical

Nuclear Fusion

ISSN

0029-5515

e-ISSN

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Volume of the periodical

58

Issue of the periodical within the volume

6

Country of publishing house

AT - AUSTRIA

Number of pages

14

Pages from-to

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UT code for WoS article

000429838000001

EID of the result in the Scopus database

2-s2.0-85047213189