Download or read book Beam Ion Driven Instabilities in NSTX written by N. N. Gorelenkov and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam Ion Driven Instabilities in NSTX written by N. N. Gorelenkov and published by . This book was released on 2003 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Study of Instabilities Driven by Energetic Neutral Beam Ions in NSTX written by E. V. Belova and published by . This book was released on 2003 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Study of Instabilities Driven by Energetic Neutral Beam Ions in NSTX written by E. V. Belova and published by . This book was released on 2003 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scaling of Kinetic Instability Induced Fast Ion Losses in NSTX written by E. Fredrickson and published by . This book was released on 2005 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parametric Dependence Of Fast ion Transport Events On The National Spherical Torus Experiment written by and published by . This book was released on 2014 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutral-beam heated tokamak plasmas commonly have more than one third of the plasma kinetic energy in the non-thermal energetic beam ion population. This population of fast ions heats the plasma, provides some of the current drive, and can affect the stability (positively or negatively) of magnetohydrodynamic instabilities. This population of energetic ions is not in thermodynamic equilibrium, thus there is free-energy available to drive instabilities, which may lead to redistribution of the fast ion population. Understanding under what conditions beam-driven instabilities arise, and the extent of the resulting perturbation to the fast ion population, is important for predicting and eventually demonstrating non-inductive current ramp-up and sustainment in NSTX-U, as well as the performance of future fusion plasma experiments such as ITER. This paper presents an empirical approach towards characterizing the stability boundaries for some common energetic-ion-driven instabilities seen on NSTX.
Download or read book Physics of Intensity Dependent Beam Instabilities written by King-Yuen Ng and published by World Scientific. This book was released on 2006 with total page 795 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive treatment of intensity dependent particle beam instabilities in accelerating rings. Written for researchers, the material is also suitable for use as a textbook in an advanced graduate course for students studying accelerator physics. The presentation starts with a brief review of the basic concept of wake potentials and coupling impedances in the vacuum chamber followed by a discussion on static and dynamic solutions of their effects on the particle beams. Special emphasis is placed separately on proton and electron machines. Other special topics of interest covered include Landau damping, BalakinOCoNovokhatskyOCoSmirnov damping, Sacherer''s integral equations, Landau cavity, saw-tooth instability, Robinson stability criteria, beam loading, transition crossing, two-stream instabilities, and collective instability issues of isochronous rings. After the formulation of an instability, readers are provided a thorough description of one or more experimental observations together with a discussion of the cures for the instability. Although the book is theory oriented, the use of mathematics has been minimized. The presentation is intended to be rigorous and self-contained with nearly all the formulas and equations derived."
Download or read book Ion beam driven Lower hybrid Instability and Resultant Anomalous Beam Slowing written by Steven W. Seiler and published by . This book was released on 1978 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book MHD Induced Neutral Beam Ion Loss from NSTX Plasmas written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Bursts of ~60 kHz activity on Mirnov coils occur frequently in NSTX plasmas and these are accompanied by bursts of neutral beam ion loss over a range in pitch angles. These losses have been measured with a scintillator type loss probe imaged with a high speed (>10,000 frames/s) video camera, giving the evolution of the energy and pitch angle distributions of the lost neutral beam ions over the course of the events. The instability occurs below the TAE frequency in NSTX (~100 kHz) in high beta plasmas and may be a beta driven Alfvén acoustic (BAAE) mode.
Download or read book Nuclear Fusion written by and published by . This book was released on 2006 with total page 1144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fast Transverse Beam Instability Caused by Electron Cloud Trapped in Combined Function Magnets written by Sergey A. Antipov and published by Springer. This book was released on 2018-11-01 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents profound insights into the origins and dynamics of beam instabilities using both experimental observations and numerical simulations. When the Recycler Ring, a high-intensity proton beam accelerator at Fermi National Accelerator Laboratory, was commissioned, it became evident that the Recycler beam experiences a very fast instability of unknown nature. This instability was so fast that the existing dampers were ineffective at suppressing it. The nature of this phenomenon, alongside several other poorly understood features of the beam, became one of the biggest puzzles in the accelerator community. The author investigated a hypothesis that the instability arises from an interaction with a dense cloud of electrons accompanying the proton beam. He studied the phenomena experimentally by comparing the dynamics of stable and unstable beams, by numerically simulating the build-up of the electron cloud and its interaction with the beam, and by constructing an analytical model of an electron cloud-driven instability with the electrons trapped in combined-function dipole magnets. He has devised a method to stabilize the beam by a clearing bunch, which conclusively revealed that the instability is caused by the electron cloud, trapped in a strong magnetic field. Finally, he conducted measurements of the microwave propagation through a single dipole magnet. These measurements have confirmed the presence of the electron cloud in combined-function magnets.
Download or read book Wiggler driven Hose Instability of an Ion focused Beam written by J.-S. Kim and published by . This book was released on 1992 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurements of Beam ion Confinement During Tangential Beam driven Instabilities in PBX Princeton Beta Experiment written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: During tangential injection of neutral beams into low density tokamak plasmas with .beta.> 1% in the Princeton Beta Experiment (PBX), instabilities are observed that degrade the confinement of beam ions. Neutron, charge-exchange, and diamagnetic loop measurements are examined in order to identify the mechanism or mechanisms responsible for the beam-ion transport. The data suggest a resonant interaction between the instabilities and the parallel energetic beam ions. Evidence for some nonresonant transport also exists.
Download or read book Effects of MHD Instabilities on Neutral Beam Current Drive written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the primary tools foreseen for heating, current drive (CD) and q-profile control in future fusion reactors such as ITER and a Fusion Nuclear Science Facility is the neutral beam injection (NBI). However, fast ions from NBI may also provide the drive for energetic particle-driven instabilities (e.g. Alfvénic modes (AEs)), which in turn redistribute fast ions in both space and energy, thus hampering the control capabilities and overall efficiency of NB-driven current. Based on experiments on the NSTX tokamak (M. Ono et al 2000 Nucl. Fusion 40 557), the effects of AEs and other low-frequency magneto-hydrodynamic instabilities on NB-CD efficiency are investigated. When looking at the new fast ion transport model, which accounts for particle transport in phase space as required for resonant AE perturbations, is utilized to obtain consistent simulations of NB-CD through the tokamak transport code TRANSP. It is found that instabilities do indeed reduce the NB-driven current density over most of the plasma radius by up to ~50%. Moreover, the details of the current profile evolution are sensitive to the specific model used to mimic the interaction between NB ions and instabilities. Finally, implications for fast ion transport modeling in integrated tokamak simulations are briefly discussed.
Download or read book Filamentation Instability of Ion Acoustic Waves Driven by a Scattered Relativistic Beam written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ion-acoustic instability driven by a scattered relativistic beam propagating in a plasma of hot electrons and cold ions is investigated. We have derived a fully electromagnetic dispersion relation and its cold beam limit and discussed the general features of the growth rate spectrum. We find that this instability is sensitively damped by th beam temperature. Particle trapping and nonlinear growth are studied by using particle-in-cell simulations.
Download or read book Self consistent Equilibrium Model of Low Aspect ratio Toroidal Plasma with Energetic Beam Ions written by E. V. Belova and published by . This book was released on 2003 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Marshall Rosenbluth Summer School 2007 written by Stefan University Press Editors and published by Stefan University Press. This book was released on 2007 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
