Fast Ion Transport During Applied 3D Magnetic Perturbations on DIII-D. PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Fast Ion Transport During Applied 3D Magnetic Perturbations on DIII-D. PDF full book. Access full book title Fast Ion Transport During Applied 3D Magnetic Perturbations on DIII-D. by . Download full books in PDF and EPUB format.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
Measurements show fast ion losses correlated with applied 3D fields in a variety of plasmas ranging from L-mode to resonant magnetic perturbation (RMP) edge localized mode (ELM) suppressed H-mode discharges. In DIII-D L-mode discharges with a slowly rotating n = 2 magnetic perturbation, scintillator detector loss signals synchronized with the applied fields are observed to decay within one poloidal transit time after beam turn-o indicating they arise predominantly from prompt loss orbits. Full orbit following using M3D-C1 calculations of the perturbed fields and kinetic profiles reproduce many features of the measured losses and points to the importance of the applied 3D field phase with respect to the beam injection location in determining the overall impact on prompt beam ion loss. Modeling of these results includes a selfconsistent calculation of the 3D perturbed beam ion birth profiles and scrape-o - layer ionization, a factor found to be essential to reproducing the experimental measurements. Extension of the simulations to full slowing down timescales, including fueling and the effects of drag and pitch angle scattering, show the applied n = 3 RMPs in ELM suppressed H-mode plasmas can induce a significant loss of energetic particles from the core. With the applied n = 3 fields, up to 8.4% of the injected beam power is predicted to be lost, compared to 2.7% with axisymmetric fields only. These fast ions, originating from minor radii> 0:7, are predicted to be primarily passing particles lost to the divertor region, consistent with wide field-of-view infrared periscope measurements of wall heating in n = 3 RMP ELM suppressed plasmas. Edge fast ion D (FIDA) measurements also con rm a large change in edge fast ion profile due to the n = 3 fields, where the effect was isolated by using short 50 ms RMP-o periods during which ELM suppression was maintained yet the fast ion profile was allowed to recover. The role of resonances between fast ion drift motion and the applied 3D fields in the context of selectively targeting regions of fast ion phase space is also discussed.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
Measurements show fast ion losses correlated with applied 3D fields in a variety of plasmas ranging from L-mode to resonant magnetic perturbation (RMP) edge localized mode (ELM) suppressed H-mode discharges. In DIII-D L-mode discharges with a slowly rotating n = 2 magnetic perturbation, scintillator detector loss signals synchronized with the applied fields are observed to decay within one poloidal transit time after beam turn-o indicating they arise predominantly from prompt loss orbits. Full orbit following using M3D-C1 calculations of the perturbed fields and kinetic profiles reproduce many features of the measured losses and points to the importance of the applied 3D field phase with respect to the beam injection location in determining the overall impact on prompt beam ion loss. Modeling of these results includes a selfconsistent calculation of the 3D perturbed beam ion birth profiles and scrape-o - layer ionization, a factor found to be essential to reproducing the experimental measurements. Extension of the simulations to full slowing down timescales, including fueling and the effects of drag and pitch angle scattering, show the applied n = 3 RMPs in ELM suppressed H-mode plasmas can induce a significant loss of energetic particles from the core. With the applied n = 3 fields, up to 8.4% of the injected beam power is predicted to be lost, compared to 2.7% with axisymmetric fields only. These fast ions, originating from minor radii> 0:7, are predicted to be primarily passing particles lost to the divertor region, consistent with wide field-of-view infrared periscope measurements of wall heating in n = 3 RMP ELM suppressed plasmas. Edge fast ion D (FIDA) measurements also con rm a large change in edge fast ion profile due to the n = 3 fields, where the effect was isolated by using short 50 ms RMP-o periods during which ELM suppression was maintained yet the fast ion profile was allowed to recover. The role of resonances between fast ion drift motion and the applied 3D fields in the context of selectively targeting regions of fast ion phase space is also discussed.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
We measured fast-ion transport caused by the combination of MHD and a mock-up test-blanket module (TBM) coil in the DIII-D tokamak. The primary diagnostic is an infrared camera that measures the heat flux on the tiles surrounding the coil. The combined effects of the TBM and four other potential sources of transport are studied: neoclassical tearing modes, Alfvén eigenmodes, sawteeth, and applied resonant magnetic perturbation fields for the control of edge localized modes. A definitive synergistic effect is observed at sawtooth crashes where, in the presence of the TBM, the localized heat flux at a burst increases from 0.36±0.27 to 2.6±0.5 MW/m-2.
Author: Michael Hanson Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
We report a DIII-D database study of the H-mode power threshold over a wide range of plasma conditions and in the presence of resonant magnetic perturbations (RMPs). This database consisting of global (i.e. averaged) quantities is first compared to the 2008 ITPA database and the resulting L-H power scaling [38]. Since ELM control is critical for ITER, and applied 3D fields will likely be present prior to the transition into the H-mode, this study is important for assessing the impact of RMP ELM suppression on the L-H power threshold. The L-H transition has been studied extensively and is dependent on the physical and magnetic divertor geometry, shear flows, and drifts, among other parameters, some of which are altered by RMP fields. In order to understand the effects of RMPs on the L-H threshold, we attempt to make a robust empirical model, using only DIII-D data, that includes magnitudes and the toroidal modes of various resonant and non-resonant 3D fields. In addition, we assess the validity of previous assumptions about fast ion losses, as well as the usefulness of 0-D database regressions for extrapolation to ITER. Results from this database study show the standard 0-D parameters to be insufficient for capturing the complex L-H transition physics at a level high enough to provide an extrapolation to ITER with reasonable certainty.
Author: Publisher: ISBN: Category : Languages : en Pages : 9
Book Description
The application of resonant magnetic perturbations (RMP) to DIII-D plasmas at low collisionality has achieved ELM suppression, primarily due to a pedestal density reduction. The mechanism of the enhanced particle transport is investigated in 3D MHD simulations with the NIMROD code. The simulations apply realistic vacuum fields from the DIII-D I-coils, C-coils and measure intrinsic error fields to an EFIT reconstructed DIII-D equilibrium, and allow the plasma to respond to the applied fields while the fields are fixed at the boundary, which lies in the vacuum region. A non-rotating plasma amplifies the resonant components of the applied fields by factors of 2-5. The poloidal velocity forms E x B convection cells crossing the separatrix, which push particles into the vacuum region and reduce the pedestal density. Low toroidal rotation at the separatrix reduces the resonant field amplitudes, but does not strongly affect the particle pumpout. At higher separatrix rotation, the poloidal E x B velocity is reduced by half, while the enhanced particle transport is entirely eliminated. A high collisionality DIII-D equilibrium with an experimentally measured rotation profile serves as the starting point for a simulation with odd parity I-coil fields that can ultimately be compared with experimental results. All of the NIMROD results are compared with analytic error field theory.
Author: Publisher: ISBN: Category : Aeronautics Languages : en Pages : 652
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: Publisher: ISBN: Category : Languages : en Pages :
Book Description
DIII-D has made significant advances in the scientific basis for fusion energy. The physics mechanism of resonant magnetic perturbation (RMP) edge localized mode (ELM) suppression is revealed as field penetration at the pedestal top, and reduced coil set operation was demonstrated. Disruption runaway electrons were effectively quenched by shattered pellets; runaway dissipation is explained by pitch angle scattering. Modest thermal quench radiation asymmetries are well described NIMROD modeling. With good pedestal regulation and error field correction, low torque ITER baselines have been demonstrated and shown to be compatible with an ITER test blanket module simulator. However performance and long wavelength turbulence degrade as low rotation and electron heating are approached. The alternative QH mode scenario is shown to be compatible with high Greenwald density fraction, with an edge harmonic oscillation demonstrating good impurity flushing. Discharge optimization guided by the EPED model has discovered a new super H-mode with doubled pedestal height. Lithium injection also led to wider, higher pedestals. On the path to steady state, 1 MA has been sustained fully non inductively with [beta]N = 4 and RMP ELM suppression, while a peaked current profile scenario provides attractive options for ITER and a [beta]N = 5 future reactor. Energetic particle transport is found to exhibit a critical gradient behavior. Scenarios are shown to be compatible with radiative and snowflake diverter techniques. Physics studies reveal that the transition to H mode is locked in by a rise in ion diamagnetic flows. Intrinsic rotation in the plasma edge is demonstrated to arise from kinetic losses. New 3D magnetic sensors validate linear ideal MHD, but identify issues in nonlinear simulations. Detachment, characterized in 2D with sub-eV resolution, reveals a radiation shortfall in simulations. As a result, future facility development targets burning plasma physics with torque free electron heating, the path to steady state with increased off axis currents, and a new divertor solution for fusion reactors.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
New phase space mapping and uncertainty analysis of energetic ion loss data in the DIII-D tokamak provides experimental results that serve as valuable constraints in first-principles simulations of energetic ion transport. Beam ion losses are measured by the fast ion loss detector (FILD) diagnostic system consisting of two magnetic spectrometers placed independently along the outer wall. Monte Carlo simulations of mono-energetic and single-pitch ions reaching the FILDs are used to determine the expected uncertainty in the measurements. Modeling shows that the variation in gyrophase of 80 keV beam ions at the FILD aperture can produce an apparent measured energy signature spanning across 50-140 keV. As a result, these calculations compare favorably with experiments in which neutral beam prompt loss provides a well known energy and pitch distribution.
Author: B. Scrosati Publisher: Springer Science & Business Media ISBN: 9401119163 Category : Science Languages : en Pages : 375
Book Description
The main motivation for the organization of the Advanced Research Workshop in Belgirate was the promotion of discussions on the most recent issues and the future perspectives in the field of Solid State lonics. The location was chosen on purpose since Belgirate was the place were twenty years ago, also then under the sponsorship of NATO, the very first international meeting on this important and interdisciplinary field took place. That meeting was named "Fast Ion Transport in Solids" and gathered virtually everybody at that time having been active in any aspect of motion of ions in solids. The original Belgirate Meeting made for the first time visible the technological potential related to the phenomenon of the fast ionic transport in solids and, accordingly, the field was given the name "Solid State lonics". This field is now expanded to cover a wide range of technologies which includes chemical sensors for environmental and process control, electrochromic windows, mirrors and displays, fuel cells, high performance rechargeable batteries for stationary applications and electrotraction, chemotronics, semiconductor ionics, water electrolysis cells for hydrogen economy and other applications. The main idea for holding an anniversary meeting was that of discussing the most recent issues and the future perspectives of Solid State lonics just twenty years after it has started at the same location on the lake Maggiore in North Italy.
Author: 
Author: 
Author: 
Author: ![Fast-ion Transport in Qmin]2, High- [beta] Steady-state Scenarios on DIII-D. PDF](https://books.google.com/books/content/images/frontcover/y4dJAQAACAAJ?fife=w80-h100)
Author: 
Author: Michael Hanson
Author: 
Author: 
Author: 
Author: 
Author: B. Scrosati