Quantification of locked mode instability triggered by a change in confinement

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F24%3A00616608" target="_blank" >RIV/61389021:_____/24:00616608 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/24:10485227

Výsledek na webu

<a href="https://iopscience.iop.org/article/10.1088/1741-4326/ad6ce7" target="_blank" >https://iopscience.iop.org/article/10.1088/1741-4326/ad6ce7</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1741-4326/ad6ce7" target="_blank" >10.1088/1741-4326/ad6ce7</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Quantification of locked mode instability triggered by a change in confinement

Popis výsledku v původním jazyce

This work presents the first analysis of the disruptive locked mode (LM) triggered by the dynamics of a confinement change. It shows that, under certain conditions, the LM threshold during the transient is significantly lower than expected from steady states. We investigate the sensitivity to a controlled n = 1 error field (EF) activated prior to the L-H transition in the COMPASS tokamak, at q95 ∼ 3, βN ∼ 1, and using EF coils on the high-field side of the vessel. A threshold for EF penetration subsequent to the L-H transition is identified, which shows no significant trend with density or applied torque, and is an apparent consequence of the reduced intrinsic rotation of the 2/1 mode during this transient phase. This finding challenges the assumption made in theoretical and empirical works that natural mode rotation can be predicted by global plasma parameters and urges against using any parametric EF penetration scaling derived from steady-state experiments to define the EF correction strategy in the entire discharge. Furthermore, even at EFs below the identified penetration threshold, disruptive locking of sawtooth-seeded 2/1 tearing modes is observed after about 30% of L-H transitions without external torque.

Název v anglickém jazyce

Quantification of locked mode instability triggered by a change in confinement

Popis výsledku anglicky

This work presents the first analysis of the disruptive locked mode (LM) triggered by the dynamics of a confinement change. It shows that, under certain conditions, the LM threshold during the transient is significantly lower than expected from steady states. We investigate the sensitivity to a controlled n = 1 error field (EF) activated prior to the L-H transition in the COMPASS tokamak, at q95 ∼ 3, βN ∼ 1, and using EF coils on the high-field side of the vessel. A threshold for EF penetration subsequent to the L-H transition is identified, which shows no significant trend with density or applied torque, and is an apparent consequence of the reduced intrinsic rotation of the 2/1 mode during this transient phase. This finding challenges the assumption made in theoretical and empirical works that natural mode rotation can be predicted by global plasma parameters and urges against using any parametric EF penetration scaling derived from steady-state experiments to define the EF correction strategy in the entire discharge. Furthermore, even at EFs below the identified penetration threshold, disruptive locking of sawtooth-seeded 2/1 tearing modes is observed after about 30% of L-H transitions without external torque.

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

2024

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

64

Číslo periodika v rámci svazku

10

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

106029

Kód UT WoS článku

001303570100001

EID výsledku v databázi Scopus

2-s2.0-85202971954