Resolving the wave–particle–plasma interaction: advances in the diagnosis, interpretation and self-consistent modelling of waves, particles and the plasma configuration

Abstract

The purpose of this review is to present the state-of-the-art in diagnosis, interpretation and modelling of waves, particles and the magnetic configuration in fusion plasmas. Knowledge of the magnetic configuration underpins all confinement, stability and transport physics, as well as being an essential prerequisite for the inference of plasma parameters from many diagnostics. As the effect of fast particles become important enough to modify the macroscopic variables of the plasma, the macroscopic fluid equations for equilibrium need to be modified to encapsulate the effects of pressure anisotropy, particle and heat flow. We present a review of such modifications in tokamak geometry, and review probabilistic validation techniques of different equilibrium models. In the last decade new spectral tools have also emerged to characterize the linear behaviour of waves and wave-modes, such as SVD, Fourier-SVD, data-mining and the bispectrum. An emerging trend is the use of statistics to characterize the nonlinear wave population of the plasma from wave field data. Finally, progress is reported on developments in understanding the physics of wave-particle resonant interactions, and the emerging science of the wave-particle-plasma interaction.

Observation of quasi-periodic frequency sweeping in electron cyclotron emission of nonequilibrium mirror-confined plasma

“…Over the years, the hole and clump mechanism has been extensively examined to study and interpret the Alfvén wave turbulence driven by high-energy beam ions or alpha particles in toroidal magnetic traps [17,[19][20][21][23][24][25][26][27][28], as well as some other MHD processes, such as fishbone [17] and ion-acoustic [29] instabilities, have been considered.…”

Trace Impurity Transport in Multi-Species Plasmas with Large Particle Fluxes

“…). (12) Note that, at t t ramp , tanh 4 ( t tramp ) → 1. This analytic result predicts a similar density profile as in the no potential case: the bulk species gradient is in the direction of the particle source despite the non-zero potential.…”

“…Cross-field transport of multiple ion species is a complex and important phenomenon in plasma science [1][2][3][4][5][6]. Its applications range widely and include controlled fusion devices, such as tokamaks [7][8][9][10][11][12][13], stellarators [14][15][16][17], and magnetized inertial fusion devices, such as MagLIF [18][19][20]. Furthermore, non-fusion devices such as plasma mass filters [21][22][23][24][25][26][27][28][29][30][31][32][33] and non-neutral particle traps [34][35][36][37][38][39] also utilize cross-field transport predictions in separating plasma components.…”

Interpretation of quasi-periodic frequency sweeping in electron cyclotron emission of nonequilibrium mirror-confined plasma sustained by high-power microwaves

“…Their subsequent convective motion in phase space is synchronized to the change in wave frequency, thus leading to complex chirping patterns in a dynamical spectrum of unstable waves. This model, commonly referred to as the Berk-Breizman theory, has been used to study the Alfven wave turbulence driven by high-energy ions in toroidal magnetic traps [12,[15][16][17][18][19][20][21][22][23]; as well as some other MHD processes, such as fishbone [12] and ion-acoustic [24] instabilities, have been considered. This paper was motivated by the first laboratory observations of potentially the same mechanism acting in a much higher electron cyclotron (EC) frequency domain reported in [25].…”