Correction of turbulent flow moments measured by Langmuir probes in the vicinity of the L-H transition in COMPASS

Kód výsledku v IS VaVaI

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Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Correction of turbulent flow moments measured by Langmuir probes in the vicinity of the L-H transition in COMPASS

Popis výsledku v původním jazyce

The analysis of turbulent flows in the edge region of tokamak plasmas requires the measurement of time-averaged turbulent stresses and fluxes such as the Reynolds stress (RS), which has been identified in recent models and experiments [1] as a likely driver of poloidal zonal flows expected to play a key role in the L-H transition. However, the common method of using floating potential fluctuations measured by Langmuir probes (LP) V˜ LP f l suffers from being contaminated by electron temperature fluctuations T˜ e[2, 3]. For the interpretation of such experiments it is worth-while to seek a correction of V˜ LP f l statistics by the exploitation of additional knowledge of T˜ estatistics offered by e.g. the combination of LP with ball-pen probes (BPP) [4]. A proof-of-principle correction scheme for the RS measured by LP was found for experimental data measured in the COMPASS tokamak with the modified Reynolds stress probe head [5]. The correction scheme is based on the decomposition of RS into statistical moments such as variance and poloidal and radial covariances of V˜ LP f l measured by LP with statistical moments of T˜ efrom BPP measurements. The correction scheme was further compared with the relationships between the associated statistical moments in comparable turbulent HESEL [6] simulations.

Název v anglickém jazyce

Correction of turbulent flow moments measured by Langmuir probes in the vicinity of the L-H transition in COMPASS

Popis výsledku anglicky

The analysis of turbulent flows in the edge region of tokamak plasmas requires the measurement of time-averaged turbulent stresses and fluxes such as the Reynolds stress (RS), which has been identified in recent models and experiments [1] as a likely driver of poloidal zonal flows expected to play a key role in the L-H transition. However, the common method of using floating potential fluctuations measured by Langmuir probes (LP) V˜ LP f l suffers from being contaminated by electron temperature fluctuations T˜ e[2, 3]. For the interpretation of such experiments it is worth-while to seek a correction of V˜ LP f l statistics by the exploitation of additional knowledge of T˜ estatistics offered by e.g. the combination of LP with ball-pen probes (BPP) [4]. A proof-of-principle correction scheme for the RS measured by LP was found for experimental data measured in the COMPASS tokamak with the modified Reynolds stress probe head [5]. The correction scheme is based on the decomposition of RS into statistical moments such as variance and poloidal and radial covariances of V˜ LP f l measured by LP with statistical moments of T˜ efrom BPP measurements. The correction scheme was further compared with the relationships between the associated statistical moments in comparable turbulent HESEL [6] simulations.

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

Europhysics conference abstracts

ISBN

979-10-96389-11-7

ISSN

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e-ISSN

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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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