Spectroscopic camera analysis of the roles of molecularly assisted reaction chains during detachment in JET L-mode plasmas

Karhunen, J. and Ben Yaala, M., JET Contributors (2023) Spectroscopic camera analysis of the roles of molecularly assisted reaction chains during detachment in JET L-mode plasmas. Nuclear Materials and Energy, 34. 101314. ISSN 2352-1791 (https://doi.org/10.1016/j.nme.2022.101314)

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Abstract

The roles of the molecularly assisted ionization (MAI), recombination (MAR) and dissociation (MAD) reaction chains with respect to the purely atomic ionization and recombination processes were studied experimentally during detachment in low-confinement mode (L-mode) plasmas in JET with the help of experimentally inferred divertor plasma and neutral conditions, extracted previously from filtered camera observations of deuterium Balmer emission, and the reaction coefficients provided by the ADAS, AMJUEL and H2VIBR atomic and molecular databases. The direct contribution of MAI and MAR in the outer divertor particle balance was found to be inferior to the electron–atom ionization (EAI) and electron–ion recombination (EIR). Near the outer strike point, a strong atom source due to the D2+-driven MAD was, however, observed to correlate with the onset of detachment at outer strike point temperatures of Te,osp=0.9–2.0 eV via increased plasma-neutral interactions before the increasing dominance of EIR at Te,osp< 0.9 eV, followed by increasing degree of detachment. The analysis was supported by predictions from EDGE2D-EIRENE simulations which were in qualitative agreement with the experimental observations.

ORCID iDs

Karhunen, J. and Ben Yaala, M. ORCID logoORCID: https://orcid.org/0000-0002-6754-0875;
  • Item type:Article
    ID code:86590
    Dates:
    Date
    Event
    31 March 2023
    Published
    11 December 2022
    Published Online
    24 November 2022
    Accepted
    Subjects:Science > Physics
    Department:Faculty of Engineering > Biomedical Engineering
    Depositing user: Pure Administrator
    Date deposited:29 Aug 2023 15:25
    Last modified:11 Nov 2024 14:04
    URI:https://strathprints.strath.ac.uk/id/eprint/86590
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