A mechanism for magnetic field stochastization and energy release during an edge pedestal collapse. (27th February 2015)

• Record Type: Journal Article
• Authors: Rhee, T.; Kim, S.S.; Jhang, Hogun; Park, G.Y.; Singh, R.
• Is Part Of: Nuclear fusion. Volume 55:Number 3(2015:Mar.)
• Publication Date: 2015-02-27
• Subjects: ELM -- nonlinear -- tearing modes -- stochastization -- energy loss -- collisionless diffusion; 05.45.-a -- 52.25.Gj -- 52.35.Mw -- 52.35.Py; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/0029-5515/55/3/032004
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: On the basis of three-dimensional nonlinear magnetohydrodynamic simulations, we propose a new dynamical process leading to the stochastization of magnetic fields during an edge pedestal collapse. Primary tearing modes are shown to grow by extracting kinetic energy of unstable ballooning modes, eventually leading to the island overlap. Secondary tearing modes, which are generated through a coherent nonlinear interaction between adjacent ballooning modes, play a key role in this process, mediating the energy transfer between primary ballooning and tearing modes. Calculations show that the parallel energy loss through the stochastic fields, which has been identified in early nonlinear simulations, could be a dominant thermal energy release mechanism during an edge pedestal collapse.