An upper pressure limit for low-Z benign termination of runaway electron beams in TCV

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F25%3A00648035" target="_blank" >RIV/61389021:_____/25:00648035 - isvavai.cz</a>

Výsledek na webu

<a href="https://iopscience.iop.org/article/10.1088/1361-6587/adbcd5/meta" target="_blank" >https://iopscience.iop.org/article/10.1088/1361-6587/adbcd5/meta</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1361-6587/adbcd5" target="_blank" >10.1088/1361-6587/adbcd5</a>

Jazyk výsledku

angličtina

Název v původním jazyce

An upper pressure limit for low-Z benign termination of runaway electron beams in TCV

Popis výsledku v původním jazyce

We present a model for the particle balance in the post-disruption runaway electron plateau phase of a tokamak discharge. The model is constructed with the help of, and applied to, experimental data from TCV discharges investigating the so-called ‘low-Z benign termination’ runaway electron mitigation scheme. In the benign termination scheme, the free electron density is first reduced in order for a subsequently induced MHD instability to grow rapidly and spread the runaway electrons widely across the wall. We show that the observed non-monotonic dependence of the free electron density with the measured neutral pressure is due to plasma re-ionization induced by runaway electron impact ionization. At higher neutral pressures, more target particles are present in the plasma for runaway electrons to collide with and ionize. Parameter scans are conducted to clarify the role of the runaway electron density and energy on the free electron density, and it is found that only the runaway electron density has a noticeable impact. While the free electron density is shown to be related to the spread of heat fluxes at termination, the exact cause for the upper neutral pressure limit remains undetermined and an object for further study.

Název v anglickém jazyce

An upper pressure limit for low-Z benign termination of runaway electron beams in TCV

Popis výsledku anglicky

We present a model for the particle balance in the post-disruption runaway electron plateau phase of a tokamak discharge. The model is constructed with the help of, and applied to, experimental data from TCV discharges investigating the so-called ‘low-Z benign termination’ runaway electron mitigation scheme. In the benign termination scheme, the free electron density is first reduced in order for a subsequently induced MHD instability to grow rapidly and spread the runaway electrons widely across the wall. We show that the observed non-monotonic dependence of the free electron density with the measured neutral pressure is due to plasma re-ionization induced by runaway electron impact ionization. At higher neutral pressures, more target particles are present in the plasma for runaway electrons to collide with and ionize. Parameter scans are conducted to clarify the role of the runaway electron density and energy on the free electron density, and it is found that only the runaway electron density has a noticeable impact. While the free electron density is shown to be related to the spread of heat fluxes at termination, the exact cause for the upper neutral pressure limit remains undetermined and an object for further study.

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

2025

Kód důvěrnosti údajů

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

Název periodika

Plasma Physics and Controlled Fusion

ISSN

0741-3335

e-ISSN

1361-6587

Svazek periodika

67

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

045015

Kód UT WoS článku

001444272500001

EID výsledku v databázi Scopus

2-s2.0-105000040110