Alpha particle redistribution due to experimentally reconstructed internal kink modes

Farengo, Ricardo; Ferrari, Hugo; Firpo, Marie-Christine; García-Martínez, Pablo; Lifschitz, Agustín

doi:10.1088/0741-3335/54/2/025007

Cited by 13 publications

(31 citation statements)

References 14 publications

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“…One group includes those studies that assume full reconnection and employ a phenomenological description of the evolution of the flux surfaces, generally including only the dominant (1,1) kink mode. The other group includes the studies that directly employ the information about the spatial and temporal evolution of the modes present in a sawtooth to calculate the trajectories of the alpha particles [14,15]. The approach employed in the studies included in the first group appears to be better suited for sawteeth that exhibit full reconnection while the one used in those included in the second group provides a more accurate description of the dynamics of alpha particles in sawteeth with partial reconnection and can include the effect of field line stochasticity.…”

Section: Introductionmentioning

confidence: 99%

“…The second approach requires knowing the space and time dependence of the electric and magnetic fields associated with the modes present in sawteeth and calculating the trajectories of a large number of particles. It has been employed by Zhao and White [14] and Farengo et al [15] and it is used in this study. The electric and magnetic fields can be obtained from theoretical calculations and/or numerical simulations, or from the experimental information.…”

Section: Introductionmentioning

confidence: 99%

“…The electric and magnetic fields can be obtained from theoretical calculations and/or numerical simulations, or from the experimental information. A method to employ the experimental information was introduced in [15] and is used here. The main assumptions and advantages of our method, and the differences with [14], are discussed in [15].…”

Section: Introductionmentioning

confidence: 99%

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Redistribution of high energy alpha particles due to sawteeth with partial reconnection

Farengo¹,

Ferrari²,

García-Martínez³

et al. 2013

Nucl. Fusion

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The redistribution of high energy alpha particles due to internal kink modes is studied in plasmas with ITER-like parameters. The exact particle trajectories in the total fields, equilibrium plus perturbation, are calculated. The equilibrium magnetic field is obtained by analytically solving the Grad–Shafranov equation and the perturbed electric and magnetic fields are reconstructed using ideal MHD and the experimental information about the displacement eigenfunction. The (1, 1), (2, 2) and (2, 1) modes are included and the effect of changing their amplitude and frequency is determined. The results show that if the conditions are similar to those reported in Igochine et al (2007 Nucl. Fusion 47 23), the peak density of counter-passing particles decreases between 25% and 40% (depending on the energy); the peak of the trapped particles density shifts outwards by approximately 10% of the minor radius and the total on axis density decreases by more than 25%. This redistribution occurs inside the q = 1 surface. The addition of a (2, 1) mode, which can produce the stochastization of the magnetic field, significantly increases particle redistribution and allows particles to spread beyond the q = 1 surface. Different groups of particles (co-passing, counter-passing, trapped) respond differently to the perturbations.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Redistribution of high energy alpha particles due to sawteeth with partial reconnection

Farengo¹,

Ferrari²,

García-Martínez³

et al. 2013

Nucl. Fusion

View full text Add to dashboard Cite

show abstract

“…Research on this subject has been mostly restricted to analytical estimations, with the exception of a few numerical studies [47,56,57,58]. The orbit parameters have been estimated solely relying on the main magnetic field components, excluding the rest of the spectrum.…”

Section: Characteristics Of Banana Orbits: τ and ∆Wmentioning

confidence: 99%

Statistical description of collisionlessα-particle transport in cases of broken symmetry: from ITER to quasi-toroidally symmetric stellarators

Gogoleva¹,

Tribaldos²,

Reynolds-Barredo³

et al. 2020

Nucl. Fusion

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Nuclear fusion has the potential to provide humanity with a safe, clean, abundant, efficient and reliable energy source for the generations to come, but up to date finding a viable fusion reactor concept remains an ongoing area of research. One of the main difficulties to attain economically viable magnetically controlled thermonuclear fusion reactors is the confinement of α-particles. These α-particles are responsible of sustaining the extreme temperatures required for nuclear reactions, and their loss poses a serious threat to the reactor operational control and to its plasma-facing components.viii RESUMEN tre los exponentes de Hurst, estimados por las técnicas Lagrangiana y Euleriana, muestra que a medida que el nivel de simetría aumenta, el transporte se vuelve fuertemente subdifusivo. Aunque, la validez del modelo fraccionario en sí mismo se vuelve dudosa en los casos limítes de alta y baja simetría.El trabajo presentado en esta tesis puede extenderse naturalmente para estudiar la validez del modelo de transporte fraccionario en otros tipos de campos magnéticos confinantes y estudiar varios efectos relacionados con las partículas α, como colisiones, perfiles de nacimiento de las partículas α, etc.

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“…Improving solely the modeling of sawteeth would be also useful for studying many effects occurring in the sawteeth regime such as the behavior of alpha particles. 4,5 In this respect, relying on a purely numerical approach may not be the most relevant approach or, at least, should be taken with care. Indeed, the numerical modeling of sawteeth is well known to be a considerably difficult task.…”

Section: Motivationsmentioning

confidence: 99%

Development of magnetohydrodynamic modes during sawteeth in tokamak plasmas

et al. 2013

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International audienceA dynamical analysis applied to a reduced resistive magnetohydrodynamics model is shown to explain the chronology of the nonlinear destabilization of modes observed in tokamak sawteeth. A special emphasis is put on the nonlinear self-consistent perturbation of the axisymmetric m=n=0 mode that manifests through the q-profile evolution. For the very low fusion-relevant resistivity values, the q-profile is shown to remain almost unchanged on the early nonlinear timescale within the central tokamak region, which supports a partial reconnection scenario. Within the resistive region, indications for a local flattening or even a local reversed-shear of the q-profile are given. The impact of this ingredient in the occurrence of the sawtooth crash is discussed

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Alpha particle redistribution due to experimentally reconstructed internal kink modes

Cited by 13 publications

References 14 publications

Redistribution of high energy alpha particles due to sawteeth with partial reconnection

Redistribution of high energy alpha particles due to sawteeth with partial reconnection

Statistical description of collisionlessα-particle transport in cases of broken symmetry: from ITER to quasi-toroidally symmetric stellarators

Development of magnetohydrodynamic modes during sawteeth in tokamak plasmas

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