Temporal characteristics of ELMs on the COMPASS divertor

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F23%3A00574103" target="_blank" >RIV/61389021:_____/23:00574103 - isvavai.cz</a>

Result on the web

<a href="https://iopscience.iop.org/article/10.1088/1741-4326/acdd10" target="_blank" >https://iopscience.iop.org/article/10.1088/1741-4326/acdd10</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1741-4326/acdd10" target="_blank" >10.1088/1741-4326/acdd10</a>

Result language

angličtina

Original language name

Temporal characteristics of ELMs on the COMPASS divertor

Original language description

The presented work shows a systematic study of the temporal characteristics of ELM events on the COMPASS divertor obtained with high temporal resolution probe measurements (∼1 μs). The resulting temporal evolution of the total ELM power on the outer target provides the values of rise (τ rise) and decay (τ decay) times for each single ELM event. It has been found that τ rise values are in the range of about 50 μs-100 μs. These values are comparable to the time of the ELM parallel propagation (τ ||) given by the sound speed and the connection length between the outer midplane and the outboard divertor. This comparison indicates that the magnetic field lines in the SOL region are not significantly ergodized during the pedestal crash on COMPASS. It also implies that the peak ELM energy fluence on the outboard divertor is dominated by the ELM parallel transport, which is confirmed by a good agreement with model prediction. In addition, the values of the ratio of τ decay and τ rise for each ELM event fit very well to the boundaries 1.5 < τ decay/τ rise < 4, as already shown on JET as well as on the HL-2A tokamak, using IR measurements. The ratio does not show any clear dependence on the relative ELM energy or line averaged electron density. It was also found that the ELM energy fluence decay length (λϵmid) is clearly linked to this ratio.

Czech name

—

Czech description

—

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

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

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

Name of the periodical

Nuclear Fusion

ISSN

0029-5515

e-ISSN

1741-4326

Volume of the periodical

63

Issue of the periodical within the volume

8

Country of publishing house

US - UNITED STATES

Number of pages

7

Pages from-to

086009

UT code for WoS article

001011391800001

EID of the result in the Scopus database

2-s2.0-85163375448