Plasma and Fusion Research

Volume 13, 1203104 (2018)

Rapid Communications

Triggering of Neoclassical Tearing Mode by Error Field Penetration
Seiya NISHIMURA and Ryusuke NUMATA1)
Department of Electric and Electronic Engineering, Hosei University, Koganei 184-8584, Japan
Graduate School of Simulation Studies, University of Hyogo, Kobe 650-0047, Japan
(Received 27 June 2018 / Accepted 22 July 2018 / Published 10 August 2018)


We conduct the first simulation study of the neoclassical tearing mode (NTM) triggered by error field penetration. A series of processes including the error field penetration, formation of seed islands, and the triggering of the NTM occurs, when the plasma flow and the electron diamagnetic drift approximately cancel out each other. The excited NTM is the born-locked mode, which is locked from the beginning. In the case where the plasma flow and the electron diamagnetic drift completely cancel out each other, a vacuum island width necessary for triggering the born-locked NTM is much smaller than a seed island width necessary for triggering the original NTM. This tendency is consistent with a theoretical prediction. Thus, whether the born-locked NTM is excited depends on both the plasma flow velocity and the error field amplitude.


neoclassical tearing mode, error field, plasma flow, perturbed bootstrap current, forced magnetic reconnection

DOI: 10.1585/pfr.13.1203104


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