Articolo in rivista, 2021, ENG, 10.1088/1741-4326/abfb14

The role of 3D fields on runaway electron mitigation in ASDEX Upgrade: a numerical test particle approach

Gobbin M.; Marrelli L.; Valisa M.; Li L.; Liu Y.Q.; Papp G.; Pautasso G.; McCarthy P.J.; the ASDEX Upgrade Team; the EUROfusion MST1 Team

CNR ISTP, Istituto per la Scienza e Tecnologia dei Plasmi, Sede di Padova - Consorzio RFX, Padova (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Italy; College of Science, Donghua University, Shanghai, China; General Atomics, San Diego, CA 92186-5608, United States of America; Max-Planck-Insitute for Plasma Physics, Garching, Germany; Department of Physics, University College Cork, Cork, Ireland.

The data collected during ASDEX Upgrade experiments in which external 3D fields have been deployed in the attempt of mitigating runaway electrons (RE) are interpreted by a numerical test particle approach. To this end the Hamiltonian guiding center code ORBIT has been used, with the implementation of the magnetic perturbation spectrum modeled by the code MARS-F, which also takes into account the plasma response to the applied 3D fields. In agreement with the observed phenomenology, ORBIT simulations show that the configuration of the currents in the top/bottom arrays of error field coils, which maximizes the plasma response to the external perturbations, is the one that most affects the high energy test electron trajectories in the edge region, thus leading to an enhancement of the energetic electron losses. This occurs in particular during the disruption, i.e. taking into account the increased toroidal electric field associated with the fast plasma cooling. Used in a predictive way, the numerical results suggest which coil configuration could further improve the RE mitigation.

Nuclear fusion 61 (6), pp. 066037-1–066037-14

Keywords

runaways, 3D fields, plasma response, particle trajectories

CNR authors

Marrelli Lionello, Gobbin Marco, Valisa Marco

CNR institutes

ISTP – Istituto per la Scienza e Tecnologia dei Plasmi

ID: 454809

Year: 2021

Type: Articolo in rivista

Creation: 2021-06-17 16:26:39.000

Last update: 2022-03-29 09:35:46.000

External IDs

CNR OAI-PMH: oai:it.cnr:prodotti:454809

DOI: 10.1088/1741-4326/abfb14

Scopus: 2-s2.0-85107160899

ISI Web of Science (WOS): 000655328600001