CNR ExploRA

Articolo in rivista, 2022, ENG, 10.1088/1741-4326/ac9634

Simulated effects of W dust ablation and deposition on the pedestal edge in JET D and DT experiments

Lazzaro E.; Causa F.; Gervasini G.; Ghezzi F.; Borodin D.; Borodkina I.; Douai D.; Huber A.; Pawelec E.; Solano E.; Sertoli M.; Widdowson A.

CNR ISTP - Istituto per la Scienza e Tecnologia dei Plasmi, Milano, Italy; Forschungszentrum Julich GmbH, Institut fur Energie-und Klimaforschung-Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), Julich, Germany; Institute of Plasma Physics of the CAS, Prague, Czech Republic; CEA, IRFM, Saint-Paul-Lez-Durance, France; Institute of Physics, University of Opole, Poland; Laboratorio Nacional de Fusion, Madrid, Espana; Tokamak Energy Ltd, Abingdon, Oxfordshire, United Kingdom; Culham Science Centre, Abingdon, Oxfordshire, United Kingdom.

A modelling analysis is performed on JET D and DT discharges, where W dust influx across the separatrix, in the pedestal edge region may affect L-H-L mode transition. The experimental basis of the proposed approach stems from the observation that transient impurity events (TIEs) are often associated with the presence of a shower of particles seen in the camera images and with strong optical emission. If the localised source of radiation is a number of heated or ablated large dust particles, then the questions addressed here are: how far will the ablated dust material penetrate and what effect will this have on the edge of the pedestal in relevant JET D and in a high fusion yield D-T discharges. The methodology is based on the use of an upgraded version of the ballistic code DUSTTRACK and a new code PELLYTIX for dust ablation modelling. Considering a reasonable amount of dust released from the tiles, the analysis shows that the ablation-penetration depth is visible in the density profiles modification, but not disastrous for tokamak operation in high regimes.

Nuclear fusion 62 (12), pp. 126037-1–126037-15