Results 161 to 170 of about 3,816 (192)

Ion cyclotron emission driven by axis-encircling energetic ions

Physics of Plasmas, 2019
Due to the large gyro-radius, most of the confined fusion products in modern medium-size tokamaks and beam ions in small tokamaks encircle the magnetic axis during the significant part of the drift orbit. As a result, a specific population of particles arises, which is characterized by strong density peaking due to equilibrium distribution in velocity ...
V. S. Marchenko, S. N. Reznik
openaire   +1 more source

Mode structure measurements of ion cyclotron emission and sub-cyclotron modes on DIII-D

Nuclear Fusion, 2022
Abstract We report mode structure measurements of coherent ion cyclotron emission (ICE) and sub-cyclotron modes on DIII-D. Through a dedicated experiment, we aimed to characterize a variety of modes via the upgraded ICE diagnostic in both L- and H-mode plasmas.
G.H. DeGrandchamp, J.B. Lestz, M.A. Van Zeeland, X.D. Du, W.W. Heidbrink, K.E. Thome, N.A. Crocker, R.I. Pinsker   +7 more
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Linear and nonlinear physics of the magnetoacoustic cyclotron instability of fusion-born ions in relation to ion cyclotron emission

Physics of Plasmas, 2014
The magnetoacoustic cyclotron instability (MCI) probably underlies observations of ion cyclotron emission (ICE) from energetic ion populations in tokamak plasmas, including fusion-born alpha-particles in JET and TFTR [Dendy et al., Nucl. Fusion 35, 1733 (1995)].
Carbajal, L., Dendy, R., Chapman, S., Cook, J.   +3 more
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Characterization of the fast ions distribution from ion cyclotron emission measurements

AIP Conference Proceedings, 2014
The ion cyclotron emission (ICE) is triggered by the free energy from an anisotropic distribution of fast ions in cyclotron resonance with plasma waves. Several theories have been developed in the hope of using the spectrum featured by this emission to extract information on the fast ion population [3], but the strong coupling between the fast ions ...
R. D'Inca, J-M. Noterdaeme, null ASDEX Upgrade Team   +2 more
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Sawtooth oscillations in ion cyclotron emission from JET

Nuclear Fusion, 1989
During ohmically heated high current deuterium discharges in JET, inverted sawtooth oscillations in the superthermal ion cyclotron emission (ICE) have been detected which cannot be accounted for by fluctuations in the antenna-plasma coupling efficiency.
P. Schild, G.A. Cottrell, R.O. Dendy
openaire   +1 more source

Generation and amplification of HM emissions by ion-cyclotron instabilities

Astrophysics and Space Science, 1973
This paper describes the analysis of the growth rate of hydromagnetic waves in the magnetosphere in ion-cyclotron mode considering multicomponent thermal plasma. Effects upon growth rate have been estimated due to (a) Thermal velocity of background plasma; (b) Presence of Heliumions in background plasma; (c) Beam Velocity; (d) Beam density.
S. N. Singh, R. Y. Prasad
openaire   +1 more source

Ion cyclotron emission on ASDEX upgrade

2014
This works deals with the Ion Cyclotron Emission (ICE), a plasma instability that takes place both in astrophysical plasmas and in fusion energy facilities like Tokamaks and Stellarators, when a population of high energetic ions is present. These fast ions can interact with the waves which propagate in the background thermal plasma and excite ...
openaire   +1 more source

Properties of quasi-periodical emission of electromagnetic ion cyclotron waves

2022
<p>Energetic electron scattering by electromagnetic ion cyclotron (EMIC) waves is one of the most effective mechanisms of electrons losses in the inner magnetosphere. Such resonant scattering has been traditionally considered as a controlling process for the dynamics of relativistic electron fluxes in the Earth’s radiation ...
Muhammad Shahid, M. Fraz Bashir, Anton Artemyev, Xiaojia Zhang, Vassilis Angelopoulos, Ghulam Murtaza   +5 more
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Ion Cyclotron Emission from JET D-T Plasmas

Physical Review Letters, 1999
Ion cyclotron emission (ICE) excited by collective instability of fusion $\ensuremath{\alpha}$ particles has been observed during deuterium-tritium experiments with radio-frequency heating and neutral beam injection (NBI) in the Joint European Torus. A model based on classical $\ensuremath{\alpha}$-particle confinement is broadly consistent with this ...
K. G. McClements, C. Hunt, R. O. Dendy, G. A. Cottrell   +3 more
openaire   +1 more source

Ion cyclotron wave emission at the quasi‐perpendicular bow shock

Journal of Geophysical Research: Space Physics, 1993
The power spectra of magnetic fluctuations occurring close to the ramp of the quasi‐perpendicular, low‐β bow shock indicate the presence of obliquely propagating electromagnetic waves with frequencies above the ion cyclotron frequency, Ωi. These waves appear to be associated with ion distributions consisting of a bi‐Maxwellian core and an energetic ...
R. O. Dendy, K. G. McClements
openaire   +1 more source