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

Result code in 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>

Result on the web

<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>

Result language

angličtina

Original language name

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

Original language description

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.

Czech name

—

Czech description

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Type

J_imp - 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

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

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

Name of the periodical

Plasma Physics and Controlled Fusion

ISSN

0741-3335

e-ISSN

1361-6587

Volume of the periodical

67

Issue of the periodical within the volume

4

Country of publishing house

US - UNITED STATES

Number of pages

9

Pages from-to

045015

UT code for WoS article

001444272500001

EID of the result in the Scopus database

2-s2.0-105000040110