RT Journal Article
T1 Analysis of Alfven eigenmode destabilization in ITER using a Landau closure model
A1 Varela, Jacobo
A1 Spong, Donald
A1 García Gonzalo, Luis
AB Alfvén eigenmodes (AE) can be destabilized during ITER discharges driven by neutral beam injection (NBI) energetic particles (EP) and alpha particles. The aim of the present study is to analyze the AE stability of different ITER operation scenarios considering multiple energetic particle species. We use the reduced magneto-hydrodynamic (MHD) equations to describe the linear evolution of the poloidal flux and the toroidal component of the vorticity in a full 3D system, coupled with equations of density and parallel velocity moments for the EP species including the effect of the acoustic modes. The AEs driven by the NBI EP and alpha particles are stable in the configurations analyzed, only MHD-like modes with large toroidal couplings are unstable, although both can be destabilized if the EP  increases above a threshold. The threshold is two times the model  value for the NBI EP and alpha particles in the reverse shear (RS) case, leading to the destabilization of Beta induced AE (BAE) near the magnetic axis with a frequency of  kHz and toroidal or elliptical AE (TAE/EAE) in the RS region with a frequency of  kHz, respectively. On the other hand, the hybrid and steady state configurations show a threshold 3 times larger with respect to the model  for the alpha particle and 40 times for the NBI EP, also destabilizing BAE and TAE between the inner and middle plasma region. In addition, a extended analysis of the RS scenario where the  of both alpha particles and NBI EP are above the AE threshold, multiple EP damping effects are also identified as well as optimization trends regarding the resonance properties of the alpha particle and NBI EP with the bulk plasma.
PB IOP Publishing
SN 0029-5515
YR 2019
FD 2019-07
LK https://hdl.handle.net/10016/32567
UL https://hdl.handle.net/10016/32567
LA eng
NO This material based on work is partially supported both by the U.S. Department of Energy, Office of Science, under Contract DE-AC05-00OR22725 with UT-Battelle, LLC and U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, using the DIII-D National Fusion Facility, a DOE Office of Science user facility, under Award No. DE-FC02-04ER54698. DIII-D data shown in this paper can be obtained in digital format by following the links at https://fusion.gat.com/global/D3D_DMP. This research was sponsored in part by the Ministerio of Economia y Competitividad of Spain under project no. ENE2015-68265-P. The authors would like to thanks Y. Todo for fruitful discussions.
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RD 1 sept. 2024