Balmer emission measurements in JET-ILW hydrogen, deuterium, tritium and deuterium-tritium low-confinement mode plasmas

Thumbnail Image

Files

Balmer_emission_measurements_in_JET-ILW_hydrogen_deuterium_tritium_and_deuterium-tritium_low-confinement_mode_plasmas.pdf (3.94 MB)

Access rights

openAccess
CC BY-NC-ND
publishedVersion

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Unless otherwise stated, all rights belong to the author. You may download, display and print this publication for Your own personal use. Commercial use is prohibited.

Authors

Date

2025-06

Department

Department of Applied Physics

Major/Subject

Mcode

Degree programme

Language

en

Pages

7

Series

Nuclear Materials and Energy, Volume 43, pp. 1-7

Abstract

Measurements of Balmer-alpha (B-α) and Balmer-gamma (B-γ), where B = H, D, or T isotopes of hydrogen, emission across the low-field side (LFS) divertor in JET ITER-like Wall (ILW), low-confinement mode (L-mode) plasma indicate that the divertor plasma was more strongly detached in deuterium, tritium and deuterium–tritium than in hydrogen plasmas. These measurements are consistent with the lower degree of detachment in hydrogen versus tritium plasmas inferred from Langmuir probes (Groth et al., 2023) [1]. The ratio of B-γ to B-α is a suitable indicator of high density/low temperature conditions because B-α emission is dominated by electron impact excitation with a small electron–ion recombination component regardless of electron temperature and density (for conditions in tokamak plasmas) whilst for B-γ the recombination component increases and the excitation component decreases as the electron temperature decreases and the electron density increases. Within the uncertainty of the measurements, the electron density at the low-field side separatrix and the power crossing the separatrix are similar to permit these comparisons.

Description

Publisher Copyright: © 2025

Keywords

Balmer, Density limit, Detachment, Divertor, DT, JET, Spectroscopy, T

Other note

DOI

10.1016/j.nme.2025.101941

Citation

Meigs, A G, Groth, M, Rikala, V P, Lomanowski, B, Vianello, N, Wischmeier, M & JET Contributors 2025, 'Balmer emission measurements in JET-ILW hydrogen, deuterium, tritium and deuterium-tritium low-confinement mode plasmas', Nuclear Materials and Energy, vol. 43, 101941, pp. 1-7. https://doi.org/10.1016/j.nme.2025.101941

Permanent link to this item

https://urn.fi/URN:NBN:fi:aalto-202506195027

Collections

[article-cris] Perustieteiden korkeakoulu / SCI