Initial TCV operation with a baffled divertor

Reimerdes, H.; Duval, B. P.; Elaian, H.; Fasoli, A.; Février, O.; Theiler, C.; Bagnato, F.; Baquero-Ruiz, M.; Blanchard, P.; Brida, D.; Colandrea, C.; Oliveira, H. De; Galassi, D.; Gorno, S.; Henderson, S.; Komm, M.; Linehan, B.; Martinelli, L.; Maurizio, R.; Moret, J.M.; Perek, A.; Raj, Harshita; Sheikh, U.; Testa, D.; Toussaint, M.; Tsui, C.; Wensing, M.

doi:10.1088/1741-4326/abd196

Cited by 39 publications

(49 citation statements)

References 19 publications

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“…Those observations were general for TCV before baffles were installed. Newer discharges with baffles installed do indicate inner target detachment during a density ramp [37]. The formation of a higher density region, near the x-point, is observed as the outer target detaches.…”

Section: Experimental Results On Tcvmentioning

confidence: 94%

A study of the influence of plasma–molecule interactions on particle balance during detachment

Verhaegh

Lipschultz

Harrison

et al. 2021

Nuclear Materials and Energy

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This paper shows experimental results from the TCV tokamak that indicate plasma-molecule interactions involving D + 2 and possibly D − play an important role as sinks of energy (through hydrogenic radiation as well as dissociation) and particles during divertor detachment if low target temperatures (< 3 eV) are achieved. Both molecular activated recombination (MAR) and ion source reduction due to a power limitation effect are shown to be important in reducing the ion target flux during a core density ramp. In contrast, the electron-ion recombination (EIR) ion sink is too small to play an important role in reducing the ion target flux. MAR or EIR do not occur during N 2 seeding induced detachment as the target temperatures are not sufficiently low.The impact of D + 2 is shown to be underestimated in present (vibrationally unresolved) SOLPS-ITER simulations, which could result from an underestimatedThe converged SOLPS-ITER simulations are post-processed with alternative reaction rates, resulting in considerable contributions of D + 2 to particle and power losses as well as dissociation below the D 2 dissociation area. Those findings are in quantitative agreement with the experimental results.

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Section: Experimental Results On Tcvmentioning

confidence: 94%

A study of the influence of plasma–molecule interactions on particle balance during detachment

Verhaegh

Lipschultz

Harrison

et al. 2021

Nuclear Materials and Energy

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show abstract

“…An important caveat regarding this analysis is that the divertor simulations for TCV used in this analysis did not have baffles installed. At this time, TCV has the option to install divertor baffles [33]. That should increase the higher neutral molecule and atom densities and may bring the TCV trends of figure 10 more in line with those shown for MAST-U.…”

Section: Understanding the Impact Of Plasma-molecule Interactions On ...mentioning

confidence: 99%

Spectroscopic investigations of detachment on the MAST Upgrade Super-X divertor

Verhaegh,

Lipschultz,

Harrison

et al. 2022

Preprint

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We present the first analysis of the atomic and molecular processes at play during detachment in the MAST-U Super-X divertor using divertor spectroscopy data. Our analysis indicates detachment in the MAST-U Super-X divertor can be separated into four sequential phases: First, the ionisation region detaches from the target at detachment onset leaving a region of increased molecular densities downstream. The plasma interacts with these molecules, resulting in molecular ions (D + 2 and/or D − 2 → D + D − ) that further react with the plasma leading to Molecular Activated Recombination and Dissociation (MAR and MAD), which results in excited atoms and significant Balmer line emission. Second, the MAR region detaches from the target leaving a sub-eV temperature region downstream. Third, an onset of strong emission from electron-ion recombination (EIR) ensues. Finally, the electron density decays near the target, resulting in a density front moving upstream.The analysis in this paper indicates that plasma-molecule interactions have a larger impact than previously reported and play a critical role in the intensity and interpretation of hydrogen atomic line emission characteristics on MAST-U. Furthermore, we find that the Fulcher band emission profile in the divertor can be used as a proxy for the ionisation region and may also be employed as a plasma temperature diagnostic for improving the separation of hydrogenic emission arising from electron-impact excitation and that from plasma-molecular interactions.We provide evidences for the presence of low electron temperatures (< 0.5 eV) during detachment phases III-IV based on quantitative spectroscopy analysis, a Boltzmann

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“…In the future, we plan to address three aspects to extend the flexibility and applicability of GBS. First, GBS will be adapted to account for the complex geometry of the tokamak wall, which may include baffles, such as those installed in TCV [70], or a complex divertor region. Second, by leveraging the relatively simple numerical scheme used in the version of GBS presented here, GBS will be ported to GPU, allowing for efficient simulations of large scale magnetic fusion devices, such as ITER and DEMO.…”

Section: Discussionmentioning

confidence: 99%

The GBS code for the self-consistent simulation of plasma turbulence and kinetic neutral dynamics in the tokamak boundary

Giacomin,

Ricci,

Coroado

et al. 2021

Preprint

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Initial TCV operation with a baffled divertor

Cited by 39 publications

References 19 publications

A study of the influence of plasma–molecule interactions on particle balance during detachment

A study of the influence of plasma–molecule interactions on particle balance during detachment

Spectroscopic investigations of detachment on the MAST Upgrade Super-X divertor

The GBS code for the self-consistent simulation of plasma turbulence and kinetic neutral dynamics in the tokamak boundary

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