Krypton can be a tool to refine and analyse the H-L power threshold in detail, as a proxy for L-H threshold, taking into account radiative losses in the region where the H-L transition takes place and, thus, decouple the power flux over the pedestal top to the one over the separatrix. The commonly used ITPA 2008 L-H threshold scaling does not account for radiation but it is often assumed that it should be compared to the net power crossing the separatrix. Yet, dedicated analyses are still lacking. At ASDEX Upgrade, krypton radiates dominantly at the very edge of the confined plasma (ρ pol between 0.97 and 1.01). Recent results show that L-H and H-L transitions are initiated close to ρ pol = 0.98. As such, the bulk of krypton radiation is between the separatrix and a potential source location for the transition. Scans in krypton seeding level and heating power have been performed to study and compare the influence of the powers radiated from inside the separatrix and the pedestal top on...

David, P., Bernert, M., Cavedon, M., Harrer, G., Eich, T. (2022). Influence of pedestal radiation on the H-L transition using krypton seeded discharges at ASDEX Upgrade. NUCLEAR FUSION, 62(10) [10.1088/1741-4326/ac8942].

Influence of pedestal radiation on the H-L transition using krypton seeded discharges at ASDEX Upgrade

Cavedon M.;
2022

Abstract

Krypton can be a tool to refine and analyse the H-L power threshold in detail, as a proxy for L-H threshold, taking into account radiative losses in the region where the H-L transition takes place and, thus, decouple the power flux over the pedestal top to the one over the separatrix. The commonly used ITPA 2008 L-H threshold scaling does not account for radiation but it is often assumed that it should be compared to the net power crossing the separatrix. Yet, dedicated analyses are still lacking. At ASDEX Upgrade, krypton radiates dominantly at the very edge of the confined plasma (ρ pol between 0.97 and 1.01). Recent results show that L-H and H-L transitions are initiated close to ρ pol = 0.98. As such, the bulk of krypton radiation is between the separatrix and a potential source location for the transition. Scans in krypton seeding level and heating power have been performed to study and compare the influence of the powers radiated from inside the separatrix and the pedestal top on...
Articolo in rivista - Articolo scientifico
impurities; L-H transition; power scaling; radiation;
English
30-ago-2022
2022
62
10
106012
none
David, P., Bernert, M., Cavedon, M., Harrer, G., Eich, T. (2022). Influence of pedestal radiation on the H-L transition using krypton seeded discharges at ASDEX Upgrade. NUCLEAR FUSION, 62(10) [10.1088/1741-4326/ac8942].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/403229
Citazioni
  • Scopus 5
  • ???jsp.display-item.citation.isi??? 5
Social impact