On the Simplification of the Modeling of Electron-Cyclotron Wave Propagation in Thermonuclear Fusion Plasmas

Tsironis, C.

doi:10.2528/pierb12102911

Cited by 6 publications

(8 citation statements)

References 32 publications

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“…Nevertheless, the ranges of values for and depend both on and . The dependence on is deduced through the comparison of curves with the same value of blob amplitude, and has been analysed in Tsironis (2013) for the mode and in Isliker et al. (2012) for the mode .…”

Section: Resultsmentioning

confidence: 99%

“…In this process, an additional assumption is that the effect of the resonant absorption on the wave dispersion is not significant; this is quantified by setting the antihermitian part of the dielectric tensor to the next asymptotic order with respect to its Hermitian part, thus implying the relation . The sequence reveals that in zero-order one follows the ray position and wavenumber, and in first order the amplitude transport, whereas the inclusion of higher-order equations partly describes wave interference and diffraction (for details the reader is pointed to Tsironis (2013)).…”

Section: Description Of the Physics Modelsmentioning

confidence: 99%

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Modelling effects of edge density fluctuations on electron-cyclotron current drive used for neoclassical tearing mode stabilization

et al. 2021

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In this work we study the undesired effects of electron density fluctuations (in the form of blob structures which may exist in the edge region of tokamak plasmas) to the electron-cyclotron wave propagation and current drive in connection to the efficiency of neoclassical tearing mode stabilization. Our model involves the evaluation of the driven current in the presence of density perturbations, by using a combination of a wave solver based on the transfer matrix and electromagnetic homogenization methods for the propagation part prior to and inside the region of these structures (where standard asymptotic propagation methods may not be valid due to the short-wavelength limit breakdown), with a ray tracing code including island geometry effects and current drive computation for the propagation past the perturbed region. The computed driven current is input into the modified Rutherford equation in order to estimate the consequences of the wave deformation (driven by the density fluctuations) to the mode stabilization.

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Section: Resultsmentioning

confidence: 99%

Section: Description Of the Physics Modelsmentioning

confidence: 99%

Modelling effects of edge density fluctuations on electron-cyclotron current drive used for neoclassical tearing mode stabilization

et al. 2021

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“…Such an assumption might produce errors due to some unwanted phenomena produced inside the plasma volume; the beam width size fluctuates (flattened) from the initial value. Nevertheless, the same situation is truth for the non-Gaussian beam [19]. However, in a large fusion device with its steepened edge density, i.e., (k 0 L n > 60) [32], and the narrow resonant layer, it will be adequate to apply Gaussian beam with large beam waist.…”

Section: Power Deposition Profiles Near Ecr Frequencymentioning

confidence: 93%

“…Heating scenario with single pass absorption of the O2-mode of 50 − 80% was obtained depending on the plasma parameters [18]. However, the advantages of using Gaussian beam in ECRH technique are that it has low ohmic losses in the transmission line, the ease in the coupling to waveguide modes, and the simplicity of modeling in theoretical studies [4,19].…”

Section: Power Transmission Windowmentioning

confidence: 99%

Study Electron Cyclotron Double Mode Conversion in Overdense Plasma

et al. 2019

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Double mode conversion from ordinary mode O to extraordinary mode X is used to achieve electron Bernstein wave (EBWs) for the electron cyclotron resonance heating (ECRH). The efficiency of the mode conversion depends on many parameters including the density gradient L n , magnetic field source B 0 and optimum launching angle N z. An analytical formalism together with a numerical computation have been employed, considering W7X stellarator main parameters, such as 140 GH z , k 0 = 29 cm −1 , 2.5 T and 2.4 ×10 20 m −3 , in order to investigate the efficiency of the mode conversion. The values of the density gradient Ln, obtained by numerical simulation, are from 1 to 10 cm. These values of L n correspond to the power transmission window T OSX from 88 to 29%. Moreover, the dispersion relation of the EBW mode propagation up to 10 harmonics, ω = 10ω ce , has been plotted to help a better visualization of the EBW mode heating. Finally, the power deposition profiles around the resonance layers were calculated and presented.

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“…Primarily, a realistic toroidal magnetic geometry must be introduced [23]. This has as a consequence the complication of the mathematical expression for the vector potential amplitude of the wave, beyond the expression given in Eq.…”

Section: Resultsmentioning

confidence: 99%

Analysis of the Cyclotron Radiation From Relativistic Electrons Interacting With a Radio-Frequency Electromagnetic Wave

Tsironis¹

2013

PIER B

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Abstract-The emission of electromagnetic radiation from charged particles spiraling around magnetic fields is an important effect in astrophysical and laboratory plasmas. In theoretical modeling, issues still not fully resolved are, among others, the inclusion of the recoil force on the relativistic electron motion and the detailed computation of the radiation power spectrum. In this paper, the cyclotron radiation emitted during the nonlinear interaction of relativistic electrons with a plane electromagnetic wave in a uniform magnetic field is examined, by analyzing the radiated power in both time and frequency domain. The dynamics of the instantaneous radiation and the emitted power spectrum from one particle, as well as from monoenergetic electron ensembles (towards a picture of the radiation properties independent of the initial conditions) is thoroughly studied. The analysis is performed for several values of the wave amplitude, focusing near the threshold for the onset of nonlinear chaos, in order to determine the alteration of the radiation in the transition from regular to chaotic motion.

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On the Simplification of the Modeling of Electron-Cyclotron Wave Propagation in Thermonuclear Fusion Plasmas

Cited by 6 publications

References 32 publications

Modelling effects of edge density fluctuations on electron-cyclotron current drive used for neoclassical tearing mode stabilization

Modelling effects of edge density fluctuations on electron-cyclotron current drive used for neoclassical tearing mode stabilization

Study Electron Cyclotron Double Mode Conversion in Overdense Plasma

Analysis of the Cyclotron Radiation From Relativistic Electrons Interacting With a Radio-Frequency Electromagnetic Wave

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