Georgia Tech Fusion Research Center Annual Report 2011

The Georgia Tech wor kon interpretation of the DIII-D experiment and on the development of the fission-fusion hybrid burner reactor (SABR) concept is described

The effects of rotation, electric field, and recycling neutrals on determining the edge pedestal density profile

© 2010 American Institute of Physics. The electronic version of this article is the complete one and can be found online at: http://link.aip.org/link/PHPAEN/v17/i5/p052506/s1DOI: 10.1063/1.3431092The edge density profile is calculated from the continuity and momentum balance equations, using experimental electric field and rotation velocities and a calculated recycling neutral source, to evaluate the relative importance of these quantities in determining the observed structure of the edge density profile in a DIII-D _J. Luxon, Nucl. Fusion 42, 614 _2002__ high-confinement mode discharge

Fusion studies program

Issued as Financial status reports [nos. 1-3], and Reports [nos. 1-5], Project E-25-63

Poloidal rotation and density asymmetries in a tokamak plasma with strong toroidal rotation

© 1992 American Institute of Physics. The electronic version of this article is the complete one and can be found online at: http://link.aip.org/link/PFBPEI/v4/i10/p3302/s1DOI: 10.1063/1.860476A neoclassical model for calculating poloidal rotation and poloidal density asymmetries in a tokamak plasma with vϕ∼vth and E/Bθ∼O(1) is developed. Application is made to the analysis of a deuterium plasma with a dominant carbon impurity. The dependences of the results on collisionality, the anomalous radial deuterium flux and the toroidal rotation speed are evaluated. The implications of the calculated poloidal velocities and density asymmetries for the magnitude of the gyroviscous torque are discussed

Neoclassical calculation of poloidal rotation and poloidal density asymmetries in tokamaks

© 2002American Institute of Physics. The electronic version of this article is the complete one and can be found online at: http://link.aip.org/link/PHPAEN/v9/i9/p3874/s1DOI: 10.1063/1.149737A previous model for the calculation of poloidal velocities and poloidal density asymmetries in the core of a tokamak plasma is refined and extended by the inclusion of terms which are important for the calculation of these quantities in the plasma edge. Agreement of predictions of the model with experiment is demonstrated. The effects of edge pressure gradient, collisionality, neutral density and up–down flux surface asymmetry on the edge poloidal rotation velocities are illustrated by a series of model problem calculations

Commentaries on Criticisms of Magnetic Fusion

This report provides brief commentaries on a representative set of the criticisms of magnetic fusion which have been published over the years and includes annexes which summarize technical information in support of the commentaries

Effect on the divertor and scrape-off layer plasma properties of the distribution of power and particle influxes from the core

© 2009 American Institute of Physics. The electronic version of this article is the complete one and can be found online at: http://link.aip.org/link/PHPAEN/v16/i3/p032506/s1DOI: 10.1063/1.3094856Calculations of the profiles along the field lines within the divertor and scrape-off layer (SOL) of differences in the plasma ion density, temperature, parallel current, parallel flow velocity, and electrostatic potential, which result from using different poloidal distributions of the particle and heat influxes crossing the separatrix from the core plasma into the SOL, are presented and discussed vis-à-vis experimental observations. The calculations show that the stronger outboard than inboard particle and heat fluxes into the SOL caused by the geometric compression/expansion of flux surfaces predicted by magnetohydrodynamic equilibrium calculations lead to a prediction of higher plasma temperature at the outboard divertor than at the inboard divertor, a result that is consistent with experimental observation and that confirms a previous prediction (made without accounting for drifts) of a possible cause of the observed in-out divertor power asymmetry. The calculations also illustrate the effect of the poloidal distribution of particle and power influx into the SOL on the flow velocity, parallel current, and electrostatic potential distributions in the SOL and divertor

Experimentally inferred thermal diffusivities in the edge pedestal between edge-localized modes in DIII-D

© 2007 American Institute of Physics. The electronic version of this article is the complete one and can be found online at:http://link.aip.org/link/PHPAEN/v14/i12/p122504/s1DOI: 10.1063/1.2817969Using temperature and density profiles averaged over the same subinterval of several successive inter-edge-localized-mode (ELM) periods, the ion and electron thermal diffusivities in the edge pedestal were inferred between ELMs for two DIII-D [ J. Luxon, Nucl. Fusion 42, 614 (2002) ] discharges. The inference procedure took into account the effects of plasma reheating and density buildup between ELMs, radiation and atomic physics cooling, neutral beam heating and ion-electron equilibration, and recycling neutral and beam ionization particle sources in determining the conductive heat flux profiles used to infer the thermal diffusivities in the edge pedestal. Comparison of the inferred thermal diffusivities with theoretical formulas based on various transport mechanisms was inconclusive insofar as identifying likely transport mechanisms

Higher Order Approximations of the TEP Method for Neutral Particle Transport in Edge Plasmas

Reprinted by permission of American Institute of Physics, http://journals.aip.orgHigher order approximations, which take into account the effects of angular anisotropy, spatial non-uniformity and energy dependence of the distribution of neutral particles, have been developed and implemented to extend the range of validity of the Transmission and Escape Probabilities (TEP) method for the calculation of neutral particle transport in plasmas. Comparisons with Monte Carlo calculations of model test problems and DIII-D L- and H- mode discharges show that these new extensions significantly improve the accuracy and extend the range of validity of the TEP methodology