Author: Carl Ernest Wagner
Publisher:
ISBN:
Category :
Languages : en
Pages : 232
Book Description
Experimental Observations of Microinstabilities in Hot-electron Plasmas
Characteristics of Microinstabilities in a Hot Electron Plasma
Experimental Investigation of Plasma Micro-instabilities in Crossed Magnetic and AC Electric Fields
Author: Alexandros J Anastassiades
Publisher:
ISBN:
Category : Electric waves
Languages : en
Pages : 298
Book Description
Publisher:
ISBN:
Category : Electric waves
Languages : en
Pages : 298
Book Description
High-frequency Microinstabilities in Hot-electron Plasmas
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Instabilities with frequencies in the neighborhood of the electron cyclotron frequency are of interest in determining stable operating regimes of hot-electron plasmas in EBT devices and in tandem mirrors. Previous work used model distributions significantly different than those suggested by recent Fokker-Planck studies. We use much more realistic model distributions in a computer code that solves the full electromagnetic dispersion relation governing longitudinal and transverse waves in a uniform plasma. We allow for an arbitrary direction of wave propagation. Results for the whistler and upper-hybrid loss-cone instabilities are presented.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Instabilities with frequencies in the neighborhood of the electron cyclotron frequency are of interest in determining stable operating regimes of hot-electron plasmas in EBT devices and in tandem mirrors. Previous work used model distributions significantly different than those suggested by recent Fokker-Planck studies. We use much more realistic model distributions in a computer code that solves the full electromagnetic dispersion relation governing longitudinal and transverse waves in a uniform plasma. We allow for an arbitrary direction of wave propagation. Results for the whistler and upper-hybrid loss-cone instabilities are presented.
Experimental Investigation of Plasma Micro-instabilities in Crossed Magnetic and AC Electric Fields
Author: Alexandros J. Anastassiades
Publisher:
ISBN:
Category : Controlled fusion
Languages : en
Pages : 0
Book Description
An anisotropic electron velocity distribution was produced in a magnetized plasma by means of an intense AC electric field near the cyclotron resonance. Unstable electrostatic waves associated with such a distribution were investigated theoretically and confirmed experimentally using the combination scattering technique. In particular, waves near the second harmonic of the electron motion imposed by the AC field were studied in detail. Their dependence on the plasma density was measured and very good agreement with the theory was obtained. Experimental observations showed that the waves were stimulated by the external AC power at least in low plasma densities. At higher plasma densities there was evidence of self-excitation. The growth rates were measured. Cyclotron harmonic electrostatic waves associated with the Maxwellian distribution, (in the absence of the AC field), were observed by means of the same technique. They were excited near the second harmonic by an extraordinary electromagnetic wave which was weakly coupled to the plasma and therefore did not perturb the thermal distribution. Qualitative agreement with the theory and other related experiments was obtained in this case. (Author).
Publisher:
ISBN:
Category : Controlled fusion
Languages : en
Pages : 0
Book Description
An anisotropic electron velocity distribution was produced in a magnetized plasma by means of an intense AC electric field near the cyclotron resonance. Unstable electrostatic waves associated with such a distribution were investigated theoretically and confirmed experimentally using the combination scattering technique. In particular, waves near the second harmonic of the electron motion imposed by the AC field were studied in detail. Their dependence on the plasma density was measured and very good agreement with the theory was obtained. Experimental observations showed that the waves were stimulated by the external AC power at least in low plasma densities. At higher plasma densities there was evidence of self-excitation. The growth rates were measured. Cyclotron harmonic electrostatic waves associated with the Maxwellian distribution, (in the absence of the AC field), were observed by means of the same technique. They were excited near the second harmonic by an extraordinary electromagnetic wave which was weakly coupled to the plasma and therefore did not perturb the thermal distribution. Qualitative agreement with the theory and other related experiments was obtained in this case. (Author).
Electron Cyclotron Heating of Plasmas
Author: Gareth Guest
Publisher: John Wiley & Sons
ISBN: 9783527627899
Category : Science
Languages : en
Pages : 264
Book Description
Authored by a highly regarded plasma scientist, this book fills the gap for a topical reference and source with a professional audience in mind. While the use of this critical method at the international fusion reactor, ITER, is covered in detail, the monograph also includes planetary magnetospheres and plasma sources for commercial applications. With exercises and solutions for additional use as course reading.
Publisher: John Wiley & Sons
ISBN: 9783527627899
Category : Science
Languages : en
Pages : 264
Book Description
Authored by a highly regarded plasma scientist, this book fills the gap for a topical reference and source with a professional audience in mind. While the use of this critical method at the international fusion reactor, ITER, is covered in detail, the monograph also includes planetary magnetospheres and plasma sources for commercial applications. With exercises and solutions for additional use as course reading.
Assessment of Hot-electron Microstability in the Initial TMX-U Experiments
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
During the initial TMX-U experiments, we investigated the sloshing-ion and hot-electron distributions. We require these components to ultimately construct a thermal barrier for improved tandem mirror confinement. The plasma parameters we achieved approach values required for thermal barrier operation but have been limited by the power available. This report is concerned with the stability of the hot electron distribution formed. Nonthermal microwave emissions near the electron-cyclotron frequency f/sub ce/ of the minimum end-cell magnetic field indicate the presence of electron microinstabilities, which we have tentatively identified by their frequencies. We observed the upper-hybrid loss-cone mode (f/f/sub ce/ approx. 1.1) during high density operation with a relatively small fraction of hot electrons. At lower density operation with a higher hot electron fraction, we observed emissions consistent with the whistler instability. During emission bursts at 12.5 GHz (f/f/sub ce/ approx. 0.9) we observed a rapid rise in the high frequency thermal emissions, indicating a spreading of the distribution. Some of the more violent bursts are correlated with enhanced end loss currents.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
During the initial TMX-U experiments, we investigated the sloshing-ion and hot-electron distributions. We require these components to ultimately construct a thermal barrier for improved tandem mirror confinement. The plasma parameters we achieved approach values required for thermal barrier operation but have been limited by the power available. This report is concerned with the stability of the hot electron distribution formed. Nonthermal microwave emissions near the electron-cyclotron frequency f/sub ce/ of the minimum end-cell magnetic field indicate the presence of electron microinstabilities, which we have tentatively identified by their frequencies. We observed the upper-hybrid loss-cone mode (f/f/sub ce/ approx. 1.1) during high density operation with a relatively small fraction of hot electrons. At lower density operation with a higher hot electron fraction, we observed emissions consistent with the whistler instability. During emission bursts at 12.5 GHz (f/f/sub ce/ approx. 0.9) we observed a rapid rise in the high frequency thermal emissions, indicating a spreading of the distribution. Some of the more violent bursts are correlated with enhanced end loss currents.
Theory of Space Plasma Microinstabilities
Author: S. Peter Gary
Publisher: Cambridge University Press
ISBN: 9780521431675
Category : Science
Languages : en
Pages : 206
Book Description
This book describes the linear theory of waves and instabilities that propagate in a collisionless plasma.
Publisher: Cambridge University Press
ISBN: 9780521431675
Category : Science
Languages : en
Pages : 206
Book Description
This book describes the linear theory of waves and instabilities that propagate in a collisionless plasma.
Experimental Comparison Between Two Magnetically Confined, Hot Electron Plasmas
Author: Charles Peter DeNeef
Publisher:
ISBN:
Category : Plasma dymanics
Languages : en
Pages : 326
Book Description
Publisher:
ISBN:
Category : Plasma dymanics
Languages : en
Pages : 326
Book Description