Direct determination of midplane background neutral density profiles from neutral particle analyzers

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F21%3A00555297" target="_blank" >RIV/61389021:_____/21:00555297 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68407700:21340/21:00356310

Výsledek na webu

<a href="https://iopscience.iop.org/article/10.1088/1741-4326/abcd75" target="_blank" >https://iopscience.iop.org/article/10.1088/1741-4326/abcd75</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1741-4326/abcd75" target="_blank" >10.1088/1741-4326/abcd75</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Direct determination of midplane background neutral density profiles from neutral particle analyzers

Popis výsledku v původním jazyce

Here we present a new method that allows the determination of background neutral density profiles based on measurements from neutral particle analyzers (NPA). Bayesian optimization is used to obtain a reliable 5-parameter representation of the inferred profiles. The method has been benchmarked using forward modelling from FIDASIM against measured data. The systematic errors coming from assumptions made in the analysis were evaluated and they are lower than 5%. The new method has been tested using data from the ASDEX Upgrade tokamak. When using reconstructed neutral density profiles, good agreement is found between the measured NPA fluxes of neutralized fast ions with predictions based on TRANSP and FIDASIM. Moreover, a clear drop of neutral density is observed at the plasma boundary after edge localized mode (ELM) activity. As suggested by KN1D simulations, this drop is mainly due to an increase of scrape-off layer (SOL) ionization rate, resulting from higher SOL plasma densities and temperatures after the ELM crash. Moreover, the new method allows calculating the local plasma ionization source which will be important for future transport studies.

Název v anglickém jazyce

Direct determination of midplane background neutral density profiles from neutral particle analyzers

Popis výsledku anglicky

Here we present a new method that allows the determination of background neutral density profiles based on measurements from neutral particle analyzers (NPA). Bayesian optimization is used to obtain a reliable 5-parameter representation of the inferred profiles. The method has been benchmarked using forward modelling from FIDASIM against measured data. The systematic errors coming from assumptions made in the analysis were evaluated and they are lower than 5%. The new method has been tested using data from the ASDEX Upgrade tokamak. When using reconstructed neutral density profiles, good agreement is found between the measured NPA fluxes of neutralized fast ions with predictions based on TRANSP and FIDASIM. Moreover, a clear drop of neutral density is observed at the plasma boundary after edge localized mode (ELM) activity. As suggested by KN1D simulations, this drop is mainly due to an increase of scrape-off layer (SOL) ionization rate, resulting from higher SOL plasma densities and temperatures after the ELM crash. Moreover, the new method allows calculating the local plasma ionization source which will be important for future transport studies.

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

<a href="/cs/project/EF16_019%2F0000768" target="_blank" >EF16_019/0000768: COMPASS-U: Tokamak pro špičkový výzkum jaderné fúze</a><br>

Návaznosti

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

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název periodika

Nuclear Fusion

ISSN

0029-5515

e-ISSN

1741-4326

Svazek periodika

61

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

AT - Rakouská republika

Počet stran výsledku

13

Strana od-do

036001

Kód UT WoS článku

000612012500001

EID výsledku v databázi Scopus

2-s2.0-85101453854