Multi-device analysis of energy loss duration and pellet penetration with implications for shattered pellet injection in ITER

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F25%3A00648056" target="_blank" >RIV/61389021:_____/25:00648056 - isvavai.cz</a>

Result on the web

<a href="https://iopscience.iop.org/article/10.1088/1741-4326/add170" target="_blank" >https://iopscience.iop.org/article/10.1088/1741-4326/add170</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1741-4326/add170" target="_blank" >10.1088/1741-4326/add170</a>

Result language

angličtina

Original language name

Multi-device analysis of energy loss duration and pellet penetration with implications for shattered pellet injection in ITER

Original language description

A robust disruption mitigation system (DMS) requires accurate characterization of key disruption timescales, one of the most notable being the thermal quench (TQ). Recent modeling of shattered pellet injection (SPI) into ITER plasmas, using JOREK and INDEX, suggests long TQ durations (6-10 ms) and slow cold front propagation due to the large plasma size. If validated, these predictions would have an impact on the desired pellet parameters and mitigation strategies for the ITER DMS. To resolve these questions, a database of SPI experiments from several small-to-large sized devices (J-TEXT, KSTAR, AUG, DIII-D, and JET) has been compiled under the auspices of the International Tokamak Physics Activity MHD, disruptions, and control topical group. Analysis of the energy loss duration (proxy for the TQ duration) with machine size is presented for both mixed neon/deuterium (Ne/D) SPI and pure deuterium (D) SPI. Several metrics for the energy loss onset (e.g. soft x-ray signal drop, I p dip, and radiation flash) were considered as the conventional metric, electron cyclotron emission, is often cut-off during SPI. Several scalings with different onset metrics showed an increase in energy loss duration with machine size. The energy loss duration was additionally shown to be a function of the ratio between the number of SPI neon atoms injected and the stored energy. Analysis of the pellet shard position relative to the cold front found that in larger devices, pellets are typically found inboard of the q = 2 surface at the energy loss onset. Lastly, the delay between the pellet shards hitting the q = 2 surface and the energy loss onset was additionally found to increase with machine size. This suggests that the pellet shards in large devices will penetrate faster and further than the cooling front.

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

Nuclear Fusion

ISSN

0029-5515

e-ISSN

1741-4326

Volume of the periodical

65

Issue of the periodical within the volume

6

Country of publishing house

US - UNITED STATES

Number of pages

17

Pages from-to

066010

UT code for WoS article

001485467400001

EID of the result in the Scopus database

2-s2.0-105005276555