Fractional Resonances between Waves and Energetic Particles in Tokamak Plasmas

Kramer, G. J.; Chen, L.; Fisher, R. K.; Heidbrink, W. W.; Nazikian, R.; Pace, D. C.; Zeeland, M. A. Van

doi:10.1103/physrevlett.109.035003

Cited by 30 publications

(39 citation statements)

References 9 publications

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“…, . Fast ion losses by energetic particle driven geodesic acoustic modes through the higher-order resonance were observed in DIII-D experiments (Kramer et al 2012). Fig.…”

Section: Energetic Particle Transport By Alfvén Eigenmodesmentioning

confidence: 84%

Introduction to the interaction between energetic particles and Alfven eigenmodes in toroidal plasmas

Todo

2018

Rev. Mod. Plasma Phys.

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This article is a tutorial review of the interaction between energetic particles and Alfvén eigenmodes (AEs) which is one of the important research issues for fusion burning plasmas. The destabilization mechanism of AEs is a kind of inverse Landau damping through the resonant interaction with energetic particles. The important properties of the AE instability, such as resonance condition, conserved variable during the interaction, and particle trapping by the AE, are explained. The time evolution of AEs is classified into various types, steady state, frequency splitting, frequency chirping, and recurrent bursts. Berk and Breizman presented both a onedimensional weakly nonlinear theory for marginal stability and a reduced simulation model that qualitatively explain the various types of time evolution. Berk-Breizman's theory and reduced simulation model are introduced, and their limitations and the future works are discussed in this article. In addition, energetic particle transport by AEs is illustrated with surface-of-section plots. The particle trapping by the AE creates phase space islands and leads to the local flattening of the energetic particle spatial profile. The resonance overlap of multiple AEs and the overlap of higherorder resonances of a single AE lead to the emergence of stochasticity in phase space and the global transport of energetic particles.

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“…, . Fast ion losses by energetic particle driven geodesic acoustic modes through the higher-order resonance were observed in DIII-D experiments (Kramer et al 2012). Fig.…”

Section: Energetic Particle Transport By Alfvén Eigenmodesmentioning

confidence: 84%

Introduction to the interaction between energetic particles and Alfven eigenmodes in toroidal plasmas

Todo

2018

Rev. Mod. Plasma Phys.

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“…Averaging is non-zero only for EPs near the resonances when the phase of EP-wave interaction accumulates (changes) integer number times 2π . In fact, even when this phase is a rational fraction of 2π there is a possibility for weak 'resonance'-like interaction [192,193]. For resonant particles the resonance condition is thus (for generality we added the cyclotron frequency…”

Section: Mhd and Kinetic Descriptionsmentioning

confidence: 99%

Energetic particle physics in fusion research in preparation for burning plasma experiments

2014

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The area of energetic particle (EP) physics in fusion research has been actively and extensively researched in recent decades. The progress achieved in advancing and understanding EP physics has been substantial since the last comprehensive review on this topic by Heidbrink and Sadler (1994 Nucl. Fusion 34 535). That review coincided with the start of deuterium-tritium (DT) experiments on the Tokamak Fusion Test Reactor (TFTR) and full scale fusion alphas physics studies. Fusion research in recent years has been influenced by EP physics in many ways including the limitations imposed by the 'sea' of Alfvén eigenmodes (AEs), in particular by the toroidicity-induced AE (TAE) modes and reversed shear AEs (RSAEs). In the present paper we attempt a broad review of the progress that has been made in EP physics in tokamaks and spherical tori since the first DT experiments on TFTR and JET (Joint European Torus), including stellarator/helical devices. Introductory discussions on the basic ingredients of EP physics, i.e., particle orbits in STs, fundamental diagnostic techniques of EPs and instabilities, wave particle resonances and others, are given to help understanding of the advanced topics of EP physics. At the end we cover important and interesting physics issues related to the burning plasma experiments such as ITER (International Thermonuclear Experimental Reactor).

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“…The effect of the increased number of resonances and the broadening is that the resonances can overlap more easily, leading to chaotic particle orbits and enhanced fast-ion transport [36,37].…”

Section: Single Partice Resonancesmentioning

confidence: 99%

A description of the full-particle-orbit-following SPIRAL code for simulating fast-ion experiments in tokamaks

Kramer

Budny

Bortolon

et al. 2013

Plasma Phys. Control. Fusion

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The numerical methods used in the full particle-orbit following SPIRAL code are described and a number of physics studies performed with the code are presented to illustrate its capabilities. The SPIRAL code is a test-particle code and is a powerful numerical tool to interpret and plan fast-ion experiments in tokamaks. Gyro-orbit effects are important for fast ions in low-field machines such as NSTX and to a lesser extent in DIII-D. A number of physics studies are interlaced between the description of the code to illustrate its capabilities. Results on heat loads generated by a localized error-field on the DIII-D wall are compared with measurements. The enhanced Triton losses caused by the same localized error-field are calculated and compared with measured neutron signals. Magnetohydrodynamic (MHD) activity such as tearing modes and toroidicity-induced Alfvén eigenmodes (TAEs) have a profound effect on the fast-ion content of tokamak plasmas and SPIRAL can calculate the effects of MHD activity on the confined and lost fast-ion population as illustrated for a burst of TAE activity in NSTX. The interaction between ion cyclotron range of frequency (ICRF) heating and fast ions depends solely on the gyro-motion of the fast ions and is captured exactly in the SPIRAL code. A calculation of ICRF absorption on beam ions in ITER is presented. The effects of high harmonic fast wave heating on the beam-ion slowing-down distribution in NSTX is also studied.

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Fractional Resonances between Waves and Energetic Particles in Tokamak Plasmas

Cited by 30 publications

References 9 publications

Introduction to the interaction between energetic particles and Alfven eigenmodes in toroidal plasmas

Introduction to the interaction between energetic particles and Alfven eigenmodes in toroidal plasmas

Energetic particle physics in fusion research in preparation for burning plasma experiments

A description of the full-particle-orbit-following SPIRAL code for simulating fast-ion experiments in tokamaks

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