Author: Anders ÖdblomPublisher:
ISBN: 9789171971647
Category :
Languages : en
Pages : 23
Book Description
Sawteeth-induced Transport in Tokamak Plasmas
Author: Anders ÖdblomPublisher:
ISBN: 9789171971647
Category :
Languages : en
Pages : 23
Book Description
Sawteeth-induced Impurity Transport in Tokamak Plasmas
Author: A. ÖdblomPublisher:
ISBN:
Category : Plasma (Ionized gases)
Languages : en
Pages : 19
Book Description
Sawteeth and Other Transport Phenomena Induced by ExB-drifts in Tokamaks
Author: Andreas OedblomPublisher:
ISBN: 9789171975959
Category :
Languages : en
Pages : 9
Book Description
Sawtooth Driven Particle Transport in Tokamak Plasmas
Author: Timothée NicolasTheory of Tokamak Plasmas
Author: R.B. WhitePublisher: North Holland
ISBN:
Category : Science
Languages : en
Pages : 388
Book Description
This is a graduate textbook on tokamak physics, designed to provide a basic introduction to plasma equilibrium, particle orbits, transport, and those ideal and resistive magnetohydrodynamic instabilities which dominate the behavior of a tokamak discharge, and to develop the mathematical methods necessary for their theoretical analysis.
Velocity-space Resolved Fast-ion Measurements in the DIII-D Tokamak
Author: Christopher Michael MuscatelloPublisher:
ISBN: 9781267260550
Category :
Languages : en
Pages : 150
Book Description
Superthermal ions in tokamak plasmas play a critical role in heating and current drive, and their confinement within the core of the plasma is crucial for obtaining ignition and sustaining burn in future reactors. At the DIII-D tokamak, a suite of fast-ion measurements is available to diagnose various properties of the superthermal population. This thesis work involves a contribution to DIII-D's fast-ion diagnostic collection: the 2nd generation fast-ion deuterium alpha (2G FIDA) detector. FIDA works on the principle of measuring the light that is emitted from neutralized fast ions that undergo charge exchange events with injected neutral atoms. 2G FIDA complements the other FIDA installations on DIII-D with its unique velocity-space sampling volume. Output from a synthetic diagnostic code (FIDAsim) that predicts FIDA emission levels is compared with measurements from 2G FIDA. We find that, while the predicted and measured shapes of the FIDA spectra agree well, the absolute magnitude of the spectral amplitudes are inconsistent. Results from various FIDAsim trials are presented adjusting several parameters, and it is hypothesized that mischaracterization of the diagnostic neutral beams is a major source of error. Instabilities in tokamaks can cause fast-ion transport. The sawtooth instability is particularly important because the crash phase has been observed to cause reductions up to 50% in the central fast-ion density. Passing ions of all energies are redistributed, but only low energy trapped ions suffer redistribution. The observations are consistent with transport by flux-attachment. Comparisons with theory suggest that the intensity of sawtooth-induced transport depends on the magnitude of toroidal drift. Instabilities characterized by toroidal and poloidal mode numbers and real frequency can coherently interact with energetic particles through mode-particle resonances. During a sawtooth crash, even fast ions whose energies are above the threshold for flux-attachment can experience transport if their orbits satisfy the bounce-precessional resonance condition. On DIII-D, a spatially localized population of beam ions accelerated above the injection energy by ion-cyclotron radio frequency (ICRF) heating is diminished at a sawtooth crash. Furthermore, fast-ion losses concurrent with sawtooth crashes are observed. Calculations show that mode-particle resonances could be responsible. Transport of energetic particles by resonant interactions pertains to many types of instabilities; other examples besides sawteeth will also be presented. Analysis shows that large amplitude modes cause significant resonant transport of fast particles. Even small amplitude modes can resonantly drive transport if multiple harmonics exist.
Lecture Series on Turbulent Transport in Tokamaks
Author: Ronald E. WaltzPublisher:
ISBN:
Category : Plasma turbulence
Languages : en
Pages : 210
Book Description
Sawteeth and Transport in Tokamaks
Author: D. J. WardPublisher:
ISBN:
Category : Electron transport
Languages : en
Pages : 5
Book Description
Scientific and Technical Aerospace Reports
Author: Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 488
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Author: