The role of the plasma current in turbulence decrease during lower hybrid current drive

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F17%3A00509309" target="_blank" >RIV/61389021:_____/17:00509309 - isvavai.cz</a>

Výsledek na webu

<a href="https://aip.scitation.org/doi/10.1063/1.4978486" target="_blank" >https://aip.scitation.org/doi/10.1063/1.4978486</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/1.4978486" target="_blank" >10.1063/1.4978486</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The role of the plasma current in turbulence decrease during lower hybrid current drive

Popis výsledku v původním jazyce

The interaction of radio frequency (RF) waves with edge turbulence has resurfaced after the results obtained on many tokamaks showing that edge turbulence decreases when the ion cyclotron frequency heating (ICRH) is switched on. Using the lower hybrid (LH) waves to drive current into tokamak plasmas, this issue presented contradicting results with some tokamaks (FTU & HT-7) showing a net decrease, similar to the ICRH results, and others (Tore Supra) did not. In this article, these apparent discrepancies among tokamaks and RF wave frequencies are removed. It is found that turbulence large-scale structures in the scrape-off layer decrease at high enough plasma currents (I-p) on the Tore Supra tokamak. We distinguish three regimes: At low I-p's, no modification is detected with statistical properties of turbulence similar to ohmic plasmas even with P-LH reaching 4.8MW. At moderate plasma currents, turbulence properties are modified only at a high LH power. At high plasma currents, turbulent large scales are reduced to values smaller than 1 cm, and this is accompanied by a net decrease in the level of turbulence of about 30% even with a moderate LH power.

Název v anglickém jazyce

The role of the plasma current in turbulence decrease during lower hybrid current drive

Popis výsledku anglicky

The interaction of radio frequency (RF) waves with edge turbulence has resurfaced after the results obtained on many tokamaks showing that edge turbulence decreases when the ion cyclotron frequency heating (ICRH) is switched on. Using the lower hybrid (LH) waves to drive current into tokamak plasmas, this issue presented contradicting results with some tokamaks (FTU & HT-7) showing a net decrease, similar to the ICRH results, and others (Tore Supra) did not. In this article, these apparent discrepancies among tokamaks and RF wave frequencies are removed. It is found that turbulence large-scale structures in the scrape-off layer decrease at high enough plasma currents (I-p) on the Tore Supra tokamak. We distinguish three regimes: At low I-p's, no modification is detected with statistical properties of turbulence similar to ohmic plasmas even with P-LH reaching 4.8MW. At moderate plasma currents, turbulence properties are modified only at a high LH power. At high plasma currents, turbulent large scales are reduced to values smaller than 1 cm, and this is accompanied by a net decrease in the level of turbulence of about 30% even with a moderate LH power.

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

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Physics of Plasmas

ISSN

1070-664X

e-ISSN

—

Svazek periodika

24

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

6

Strana od-do

032307

Kód UT WoS článku

000397872500032

EID výsledku v databázi Scopus

2-s2.0-85016139828