Upstream and downstream properties of turbulent transport at tokamak COMPASS

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F19%3A00365934" target="_blank" >RIV/68407700:21340/19:00365934 - isvavai.cz</a>

Výsledek na webu

<a href="http://ocs.ciemat.es/EPS2019PAP/pdf/P2.1099.pdf" target="_blank" >http://ocs.ciemat.es/EPS2019PAP/pdf/P2.1099.pdf</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Upstream and downstream properties of turbulent transport at tokamak COMPASS

Popis výsledku v původním jazyce

Turbulent transport in the Scrape-Off Layer (SOL) is an important issue in contemporary tokamak physics due to its role in deteriorating plasma confinement and enhancing the plasma-wall interaction. This work compares turbulence properties on two poloidal locations, the outer midplane (upstream) and the divertor target (downstream), and interprets their similarities and differences in terms of parallel transport of turbulent structures. The experimental data was measured at tokamak COMPASS, Prague, using Langmuir and ball-pen probes mounted on a reciprocating manipulator or embedded into a divertor tile. The analysis input are mainly measurements of the ion saturated current Isat , supplemented by measurements of the electron temperature Te with high temporal resolution (several μs) using the ball-pen/Langmuir probe technique [1]. To compare the upstream and downstream fluctuations of these quantities, several techniques are employed. Probability distribution functions (PDF) of the fluctuations are drawn, together with the skewness and kurtosis profiles, and their dependence on the plasma collisionality is investigated. To estimate the blob coherence along the field line, correlation of upstream and target fluctuations is attempted; however, uncertainties in the magnetic equililibrium reconstruction prove to be a major challenge in this task. The importance of Te fluctuations on the root Isat ∝ ne Te PDF is investigated, and it is found to be quite large, distorting the exponential tail of ne fluctuations into a more general shape.

Název v anglickém jazyce

Upstream and downstream properties of turbulent transport at tokamak COMPASS

Popis výsledku anglicky

Turbulent transport in the Scrape-Off Layer (SOL) is an important issue in contemporary tokamak physics due to its role in deteriorating plasma confinement and enhancing the plasma-wall interaction. This work compares turbulence properties on two poloidal locations, the outer midplane (upstream) and the divertor target (downstream), and interprets their similarities and differences in terms of parallel transport of turbulent structures. The experimental data was measured at tokamak COMPASS, Prague, using Langmuir and ball-pen probes mounted on a reciprocating manipulator or embedded into a divertor tile. The analysis input are mainly measurements of the ion saturated current Isat , supplemented by measurements of the electron temperature Te with high temporal resolution (several μs) using the ball-pen/Langmuir probe technique [1]. To compare the upstream and downstream fluctuations of these quantities, several techniques are employed. Probability distribution functions (PDF) of the fluctuations are drawn, together with the skewness and kurtosis profiles, and their dependence on the plasma collisionality is investigated. To estimate the blob coherence along the field line, correlation of upstream and target fluctuations is attempted; however, uncertainties in the magnetic equililibrium reconstruction prove to be a major challenge in this task. The importance of Te fluctuations on the root Isat ∝ ne Te PDF is investigated, and it is found to be quite large, distorting the exponential tail of ne fluctuations into a more general shape.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

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Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název statě ve sborníku

46th EPS Conference on Plasma Physics

ISBN

979-10-96389-11-7

ISSN

0378-2271

e-ISSN

0378-2271

Počet stran výsledku

4

Strana od-do

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Název nakladatele

European Physical Society

Místo vydání

Mulhouse Cedex

Místo konání akce

Miláno

Datum konání akce

8. 7. 2019

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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