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

Result code in 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>
Alternative codes found
RIV/68407700:21340/21:00356310
Result on the web
<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>

Result language
angličtina
Original language name
Direct determination of midplane background neutral density profiles from neutral particle analyzers
Original language description
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.
Czech name
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Czech description
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Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
—
OECD FORD branch
10305 - Fluids and plasma physics (including surface physics)

Project
<a href="/en/project/EF16_019%2F0000768" target="_blank" >EF16_019/0000768: COMPASS-U: Tokamak for cutting-edge fusion research</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year
2021
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

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