Download or read book Interaction Between Energetic Particles and Sawtooth Instabilities in Tokamak Plasmas written by Yi Zhao and published by . This book was released on 1997 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sawtooth Control and the Interaction of Energetic Particles written by and published by . This book was released on 2008 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The effect of energetic particles on stability of mirror and tokamak plasmas written by Daren Price Stotler and published by . This book was released on 1986 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energetic Particle Physics with Applications in Fusion and Space Plasmas written by C. Z. Cheng and published by . This book was released on 1997 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energetic Particle Physics with Applications in Fusion and Space Plasmas written by C.Z. Cheng and published by . This book was released on 1997 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Velocity space Resolved Fast ion Measurements in the DIII D Tokamak written by Christopher Michael Muscatello and published by . This book was released on 2012 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Sawtooth Stabilization by Energetic Trapped Particles written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent experiments involving high power radio-frequency heating of a tokamak plasma show strong suppression of the sawtooth oscillation. A high energy trapped particle population is shown to have a strong stabilizing effect on the internal resistive kink mode. Numerical calculations are in reasonable agreement with experiment. 13 refs., 2 figs.
Download or read book Expulsion of Energetic Ions from the Plasma Core in the Presence of Sawtooth Oscillations in Spherical Tokamaks written by Ya. I. Kolesnichenko and published by . This book was released on 2000 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Sawtooth Oscillations on Energetic Ions written by Ya. I. Kolesnichenko and published by . This book was released on 1999 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetohydrodynamic Stability of Tokamaks written by Hartmut Zohm and published by John Wiley & Sons. This book was released on 2015-02-09 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book bridges the gap between general plasma physics lectures and the real world problems in MHD stability. In order to support the understanding of concepts and their implication, it refers to real world problems such as toroidal mode coupling or nonlinear evolution in a conceptual and phenomenological approach. Detailed mathematical treatment will involve classical linear stability analysis and an outline of more recent concepts such as the ballooning formalism. The book is based on lectures that the author has given to Master and PhD students in Fusion Plasma Physics. Due its strong link to experimental results in MHD instabilities, the book is also of use to senior researchers in the field, i.e. experimental physicists and engineers in fusion reactor science. The volume is organized in three parts. It starts with an introduction to the MHD equations, a section on toroidal equilibrium (tokamak and stellarator), and on linear stability analysis. Starting from there, the ideal MHD stability of the tokamak configuration will be treated in the second part which is subdivided into current driven and pressure driven MHD. This includes many examples with reference to experimental results for important MHD instabilities such as kinks and their transformation to RWMs, infernal modes, peeling modes, ballooning modes and their relation to ELMs. Finally the coverage is completed by a chapter on resistive stability explaining reconnection and island formation. Again, examples from recent tokamak MHD such as sawteeth, CTMs, NTMs and their relation to disruptions are extensively discussed.
Download or read book Plasma Physics and Controlled Nuclear Fusion Research written by and published by . This book was released on 1987 with total page 774 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energetic Particles in Spherical Tokamak Plasmas written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy and Water Development Appropriations for 2009 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2008 with total page 1490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Alfv n Modes and Wave particle Interaction in a Tokamak written by Meng Li and published by . This book was released on 2017 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work is motivated by the nonlinear wave-particle interaction problems. To build a self-consistent theory, we consider eigenmodes of the bulk plasma as well as the dynamics of the energetic particles. The modes of our particular interest are the Alfvén Cascades and the Toroidicity Alfven Eigenmodes (TAE), which we describe using Magnetohydrodynamic(MHD) analysis and the AEGIS codes. We investigate the stabilizing effect for the Alfvenic waves from continuum damping, especially near the TAE gap. For the kinetic description of the energetic particles, we propose new canonical straight field line coordinates to model the guiding center motion. We then formulate wave-particle interaction problem using the action-angle variables. In Chapter 2, we interpret Alfvén Cascades observed in Madison Symmetric Torus (MST). We do linear MHD calculations and find the mode frequency, structure, and stability boundary. We then perform MHD simulation using the AEGIS code, with the equilibrium reconstructed from experiment. The result is discussed and compared with the experimentally observed features. In Chapter 3, we analyze continuum damping for Alfvénic waves, especially in the extreme situation near the TAE gap. We find that the continuum tip absorption feature is actually related to the existing of TAEs in the gap. On the technical level, we improve the numerical scheme of AEGIS and resolve two closely-spaced singularities. As a result, the absorption features observed in the simulation show good agreement with our analytical calculation. In order to simulate the energetic particle guiding center motion in the Hamiltonian form, we propose a new set of straight magnetic field line coordinates. The new coordinates exist for general tokamak devices and facilitate both MHD calculations and energetic particles. The new coordinate system makes it very convenient to take the advantage of the Hamiltionian structure of the guiding center motion. We use a canonical transformation to action-angle variables to formulate the interaction model for particles. The action-angle variables allow us to resolve wave-particle resonances and describe the conserved quantities for resonance particles. The model can give us a complete picture for nonlinear stage of wave-particle interaction.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fusion Energy Update written by and published by . This book was released on 1986 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
