Browsing Fusion Research Center (FRC) by Subject "Tokamak devices"
Now showing items 118 of 18

Analysis of neutral particle recycling and pedestal fueling in a Hmode DIIID discharge
(Georgia Institute of TechnologyAmerican Institute of Physics, 20100223)A detailed analysis of neutral atom recycling and pedestal fueling in a DIIID _J. Luxon, Nucl. Fusion 42, 614 _2002__ highconfinement mode discharge is presented. Experimental data and twodimensional _2D_ edge plasma ... 
Applications of the Miller equilibrium to extend tokamak computational models
(Georgia Institute of TechnologyAmerican Institute of Physics, 20081211)An analytical model for the equilibrium flux surface geometry, widely known as the Miller equilibrium model, has been exploited to improve a variety of simplified tokamak computation models that incorporate an approximate ... 
An edge pedestal model based on transport and atomic physics
(Georgia Institute of TechnologyAmerican Institute of Physics, 200109)A model is presented for the calculation of the characteristic scale lengths from transport considerations in the edge pedestal region of high confinement (Hmode) plasmas. The model is based on the requirements of heat ... 
The Effect of Ion Orbit Loss and XLoss on the Interpretation of Ion Energy and Particle Transport in the DIIID Edge Plasma
(Georgia Institute of TechnologyAmerican Institute of Physics, 20111014)Calculation models are presented for treating ion orbit loss effects in interpretive fluid transport calculations for the tokamak edge pedestal. Both standard ion orbit loss of particles following trapped or passing orbits ... 
The effects of rotation, electric field, and recycling neutrals on determining the edge pedestal density profile
(Georgia Institute of TechnologyAmerican Institute of Physics, 20100519)The 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 ... 
Experimentally inferred thermal diffusivities in the edge pedestal between edgelocalized modes in DIIID
(Georgia Institute of TechnologyAmerican Institute of Physics, 20071211)Using temperature and density profiles averaged over the same subinterval of several successive interedgelocalizedmode (ELM) periods, the ion and electron thermal diffusivities in the edge pedestal were inferred between ... 
Extension and comparison of neoclassical models for poloidal rotation in tokamaks
(Georgia Institute of TechnologyAmerican Institute of Physics, 20080118)Several neoclassical models for the calculation of poloidal rotation in tokamaks were rederived within a common framework, extended to include additional physics and numerically compared. The importance of new physics ... 
Force Balance and Ion Particle Transport Differences in High and Low Confinement Tokamak Edge Pedestals
(Georgia Institute of TechnologyAmerican Institute of Physics, 20101122)The various terms in the radial force balance in the edge plasma are evaluated using experimental data from the low (L) and high (H) confinement phase of a DIIID [J. Luxon, Nucl. Fusion 42, 614 (2002)] discharge in order ... 
Interpretation of edge pedestal rotation measurements in DIIID
(Georgia Institute of TechnologyAmerican Institute of Physics, 20080125)A novel methodology for inferring experimental toroidal angular momentum transfer rates from measured toroidal rotation velocities and other measured quantities has been developed and applied to analyze rotation measurements ... 
Interpretation of particle pinches and diffusion coefficients in the edge pedestal of DIIID Hmode plasmas
(Georgia Institute of TechnologyAmerican Institute of Physics, 20091015)A procedure is described for evaluating particle pinches to be used in interpreting particle diffusion coefficients from measured density and temperature profiles in the edge pedestal of tokamak plasmas. Application to the ... 
Investigation of background edge thermal transport in ELMing and ELMsuppressed Hmodes in DIIID
(Georgia Institute of TechnologyAmerican Institute of Physics, 20061117)Thermal diffusivities are inferred in the plasma edge of a matched pair of DIIID [J. Luxon, Nucl. Fusion 42, 614 (2002)] high confinement mode discharges, one with edge localized modes (ELMs) present and the other with ... 
An investigation of some effects of drifts and magnetic field direction in the scrapeoff layer and divertor of tokamak plasmas
(Georgia Institute of TechnologyAmerican Institute of Physics, 20090403)Various effects of particle drifts in the scrapeoff layer (SOL) and divertor of tokamaks have been calculated. The predictions are consistent with several experimentally observed phenomena, e.g., the double reversal of ... 
Neoclassical theory for rotation and impurity transport in tokamaks with neutral beam injection
(Georgia Institute of TechnologyAmerican Institute of Physics, 200101)A selfconsistent, firstprinciples neoclassical theory for rotation and impurity transport in tokamaks is presented. The implications of this theory for impurity transport in a tokamak are illustrated by a model problem ... 
Poloidal rotation and density asymmetries in a tokamak plasma with strong toroidal rotation
(Georgia Institute of TechnologyAmerican Institute of Physics, 199210)A 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 ... 
Poloidal rotation, density asymmetries, and momentum confinement in tokamak experiments
(Georgia Institute of TechnologyAmerican Institute of Physics, 199306)Poloidal rotation speeds and density asymmetries are calculated for the deuterium and dominant carbon (oxygen) impurity ions in discharges in the Axially Symmetric Divertor Experiment (ASDEX) [Proceedings of the 13th ... 
Representation of the plasma fluid equations in "Miller equilibrium" analytical flux surface geometry
(Georgia Institute of TechnologyAmerican Institute of Physics, 20090803)The plasma fluid equations are represented explicitly in the magnetic flux surface coordinate system resulting from the analytical “Miller equilibrium” solution of the Grad–Shafranov equation. The magnetic geometry is ... 
Rotation velocities in the plasma edge driven viscously by scrapeoff layer flows
(Georgia Institute of TechnologyAmerican Institute of Physics, 20090625)Scrapeoff layer parallel flows and the viscous fluxes in the plasma edge driven thereby are calculated from neoclassical theory for a model problem representative of a present experiment, using an analytical model for ... 
Thermal transport analysis of the edge region in the low and high confinement stages of a DIIID discharge
(Georgia Institute of TechnologyAmerican Institute of Physics, 20070104)The ion and electron thermal diffusivities have been inferred from measured density and temperature profiles in the edge of a DIIID [ J. Luxon, Nucl. Fusion 42, 614 (2002) ] discharge with a low confinement (Lmode) stage ...