Since 18 of December 2019 conferences.iaea.org uses Nucleus credentials. Visit our help pages for information on how to Register and Sign-in using Nucleus.

17–22 Oct 2016
Kyoto International Conference Center
Japan timezone

Role of explosive instabilities in high-beta disruptions in tokamaks

18 Oct 2016, 08:30
4h
Kyoto International Conference Center

Kyoto International Conference Center

Takaragaike, Sakyo-ku, Kyoto 606-0001 Japan
Poster THS - Magnetic Confinement Theory and Modelling: Stability Poster 1

Speaker

Dr Ahmet Aydemir (National Fusion Research Institute, Daejeon, Korea)

Description

Explosive growth of a ballooning finger is demonstrated in nonlinear magnetohydrodynamic calculations of high-beta disruptions in tokamaks. The explosive finger is formed by an ideally unstable n=1 mode, dominated by an m/n=2/1 component. The quadrupole geometry of the 2/1 perturbed pressure field provides a generic mechanism for the formation of the initial ballooning finger and its subsequent transition from exponential to explosive growth, without relying on secondary processes. The explosive ejection of the hot plasma from the core and stochastization of the magnetic field occur in Alfvenic time scales, accounting for the extremely fast growth of the precursor oscillations and the rapidity of the thermal quench in some high-beta disruptions.
Country or International Organization South Korea
Paper Number TH/P1-17

Primary author

Dr Ahmet Aydemir (National Fusion Research Institute, Daejeon, Korea)

Co-authors

Dr Byoungho Park (National Fusion Research Institute) Dr Hyungho LEE (National Fusion Research Institute) Dr JaeChun Seol (National Fusion Research Institute) Dr Sang Gon Lee (National Fusion Research Institute) Dr Yongkyoon In (National Fusion Research Institute)

Presentation materials