(TH/P8-3) Extended Magnetohydrodynamic Simulations of Edge Localized Modes in Existing and Future Tokamak Devices

C.R. Sovinec1), A.Y. Pankin2), S.E. Kruger3), D.P. Brennan4), P.B. Snyder5), D.D. Schnack1), E.D. Held6), D.C. Barnes7), G. Bateman2), A.H. Kritz2), S.C. Jardin9), J. Breslau9)
 
1) University of Wisconsin-Madison, Madison, Wisconsin, USA
2) Lehigh University, Bethlehem, Pennsylvania, USA
3) Tech-X Corporation, Boulder, Colorado, USA
4) Tulsa University, Tulsa, Oklahoma, USA
5) General Atomics, San Diego, California, USA
6) Utah State University, Logan, Utah, USA
7) Los Alamos National Laboratory, Los Alamos, New Mexico, USA
8) University of Colorado, Boulder, Colorado, USA
9) PPPL, Princeton, New Jersey, USA

Abstract.  Studies of ELMs using the nonlinear, initial-value code NIMROD code are presented. Linear studies of ELMs show the the effects of diffusivities do not qualitatively change the linear mode spectrum as compared to linear ideal MHD studies. Two-fluid effects change the linear spectrum by stabilizing high-n modes. Nonlinear simulations presented in this work are the first to show significant plasma-wall interactions as a result of an ELM instability over a global computational domain. The nonlinear evolution of the linear modes drives a rapid loss of internal energy with approximately 70 kJ (10%) of the internal energy being lost within 60 ms. The computation finds that the primary loss channel is convective (n$ \vec{{V}} $T) rather than conductive ($ \vec{{q}} $), which is not inconsistent with laboratory measurements. The ability to reproduce these important laboratory measurements suggests that nonlinear fluid simulations have potential to provide significant insight into how ELMs evolve and deposit heat onto the wall. We also present how a combination of linear and nonlinear results can be used for integrated modeling of future reactors.

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