Alfven Cyclotron Instability and Ion Cyclotron Emission

Alfven Cyclotron Instability and Ion Cyclotron Emission PDF Author: N. N. Gorelenkov
Publisher:
ISBN:
Category : Alpha rays
Languages : en
Pages : 23

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Alfven Cyclotron Instability and Ion Cyclotron Emission

Alfven Cyclotron Instability and Ion Cyclotron Emission PDF Author: N. N. Gorelenkov
Publisher:
ISBN:
Category : Alpha rays
Languages : en
Pages : 23

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Alfven Cyclotron Instability and Ion Cyclotron Emission

Alfven Cyclotron Instability and Ion Cyclotron Emission PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 24

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Two-dimensional solutions of compressional Alfven eigenmodes (CAE) are studied in the cold plasma approximation. For finite inverse aspect ratio tokamak plasmas the two-dimensional eigenmode envelope is localized at the low magnetic field side with the radial and poloidal localization on the order of a/√m and a/(fourth root of m), respectively, where m is the dominant poloidal mode number. Charged fusion product driven Alfven Cyclotron Instability (ACI) of the compressional Alfven eigenmodes provides the explanation for the ion cyclotron emission (ICE) spectrum observed in tokamak experiments. The ACI is excited by fast charged fusion products via Doppler shifted cyclotron wave-particle resonances. The ion cyclotron and electron Landau dampings and fast particle instability drive are calculated perturbatively for deuterium-deuterium (DD) and deuterium-tritium (DT) plasmas. Near the plasma edge at the low field side the velocity distribution function of charged fusion products is localized in both pitch angle and velocity. The poloidal localization of the eigenmode enhances the ACI growth rates by a factor of √m in comparison with the previous results without poloidal envelope. The thermal ion cyclotron damping determines that only modes with eigenfrequencies at multiples of the edge cyclotron frequency of the background ions can be easily excited and form an ICE spectrum similar to the experimental observations. Theoretical understanding is given for the results of TFTR DD and DT experiments with [upsilon]{sub {alpha}0}/[upsilon]{sub A} 1 and JET experiments with [upsilon]{sub {alpha}0}/[upsilon]{sub A} 1.

Alfvén/ion Cyclotron Waves

Alfvén/ion Cyclotron Waves PDF Author: Barry Hulett Mauk
Publisher:
ISBN:
Category : Cyclotron waves
Languages : en
Pages : 328

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Excitation of Alfven Cyclotron Instability by Charged Fusion Products in Tokamaks

Excitation of Alfven Cyclotron Instability by Charged Fusion Products in Tokamaks PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The spectrum of ion cyclotron emission (ICE) observed in tokamak experiments shows narrow peaks at multiples of the edge cyclotron frequency of background ions. A possible mechanism of ICE based on the fast Alfven Cyclotron Instability (ACI) resonantly excited by high energy charged products ([alpha]-particles or protons) is studied here. The two-dimensional ACI eigenmode structure and eigenfrequency are obtained in the large tokamak aspect ratio limit. The ACI is excited via wave-particle resonances in phase space by tapping the fast ion velocity space free energy. The instability growth rates are computed perturbatively from the perturbed fast particle distribution function, which is obtained by integrating the high frequency gyrokinetic equation along the particle orbit. Numerical examples of ACI growth rates are presented for TFTR plasmas. The fast ion distribution function is assumed to be singular in pitch angle near the plasma edge. The results are employed to understand the ICE in Deuterium-Deuterium (DD) and Deuterium-tritium (DT) tokamak experiments.

Alfven-ion-cyclotron Instability in Mirror Machines

Alfven-ion-cyclotron Instability in Mirror Machines PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Electrostatic instabilities occurring in mirror-confined ion velocity-distributions have been thoroughly investigated. The electromagnetic instability of greatest concern is the Alfven-ion-cyclotron (AIC) mode. In this work we investigate both convective and absolute growth, both in homogeneous plasma and in finite machines, for a variety of ion velocity-distributions. Good agreement is found with the results from the particle simulation code ''Superlayer''. Quasilinear effects are outlined and a rough criterion found for the importance of Dupree-type broadening.

Proceedings of the Workshop on the Current-Driven Electrostatic Ion-Cyclotron Instability, July 9/10, 1987, Innsbruck, Austria

Proceedings of the Workshop on the Current-Driven Electrostatic Ion-Cyclotron Instability, July 9/10, 1987, Innsbruck, Austria PDF Author: R. Schrittwieser
Publisher: World Scientific Publishing Company
ISBN:
Category : Science
Languages : en
Pages : 188

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Saturation and Post-saturation Behavior of the Alfvén Ion-cyclotron Instability

Saturation and Post-saturation Behavior of the Alfvén Ion-cyclotron Instability PDF Author: Niels Fujio Otani
Publisher:
ISBN:
Category :
Languages : en
Pages : 19

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The Alfvén Ion-cyclotron Instability

The Alfvén Ion-cyclotron Instability PDF Author: Niels Fujio Otani
Publisher:
ISBN:
Category :
Languages : en
Pages : 26

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Alfven-ion-cyclotron Instability in the Central Cell of TMX.

Alfven-ion-cyclotron Instability in the Central Cell of TMX. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The central cell of TMX may require hot-ion injection. The resulting velocity-space anisotropy together with the length of the central homogeneous region raise the possibility of convective AIC instability. In this report we demonstrate that the Rosenbluth criterion of less than a thousand-fold amplitude amplification per pass can be satisfied by ion distributions which nevertheless have sufficient anisotropy to be confined within the central cell.

Whistler and Alfvén Mode Cyclotron Masers in Space

Whistler and Alfvén Mode Cyclotron Masers in Space PDF Author: V. I︠U︡ Trakhtengert︠s︡
Publisher: Cambridge University Press
ISBN: 0521871980
Category : Science
Languages : en
Pages : 355

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Book Description
This book describes whistler and Alfvén cyclotron masers for researchers and graduates in space science, solar-terrestrial physics, and plasma physics.