UKAEA Papers

"Adiabatic invariants and the equilibrium of magnetically trapped particles"

• RJ Hastie
• JB Taylor
• FA Haas

"The stability of a circular toroidal plasma under average magnetic well conditions with finite plasma pressure"

• AA Ware
• FA Haas

"An Error Analysis of Dimensionless Confinement Scaling Experiments"

• J.G. Cordey

Recently several tokamak experiments have been completed to try and elucidate the scaling of the confinement with the key dimensionless parameters ρ*, ν* and β. It has been shown theoretically that these 3 parameters are fundamental in determining the scaling of the energy confinement [1-3]. The experimental results, which consist of single scan…

"DATA VALIDATION, ANALYSIS, AND APPLICATIONS FOR FUSION PLASMAS"

• S. A. Arshad
• J. G. Cordey
• D. C. Mcdonald
• J. Farthing
• E. Joffrin
• M. Von Hellermann
• C. M. Roach
• J. Svensson

Principal techniques and trends in the validation and analysis of data in magnetic fusion research are described and examples of applications are given. Wellestablished methods to obtain key physical quantities are outlined, as well as newer techniques employing integrated analysis of multiple diagnostics to improve quality and extract additional i…

"A nonlinear dynamic model of relaxation oscillations in tokamaks"

• A. Thyagaraja
• F. A. Haas
• D. J. Harvey

Tokamaks exhibit several types of relaxation oscillations such as sawteeth, fishbones and Edge Localized Modes (ELMs) under appropriate conditions. Several authors have introduced model nonlinear dynamic systems with a small number of degrees of freedom which can illustrate the generic characteristics of such oscillations. In these models, one focu…

"Two novel applications of bootstrap currents: Snakes and jitter stabilization"

• A. Thyagaraja
• F. A. Haas

Both neoclassical theory and certain turbulence theories of particle transport in tokamaks predict the existence of bootstrap (i.e., pressure-driven) currents. Two new applications of this form of noninductive current are considered in this work. In the first, an earlier model of the nonlinearly saturated m= 1 tearing mode is extended to include th…

"Toroidal effects on the nonlinearly saturated m=1 island in tokamaks"

• K. Avinash
• F. A. Haas
• A. Thyagaraja

This Brief Communication investigates the influence of toroidal effects (due to the coupling of various poloidal harmonics) on the nonlinear saturation of the m = 1 island. Bounds are obtained relating the aspect ratio, the shear at the q= 1 surface, and the saturated island width. Provided these bounds are satisfied, it is then found that the cyli…

"The relationship between q profiles, transport, and sawteeth in tokamaks"

• F. A. Haas
• A. Thyagaraja

The purpose of this paper is to investigate the possible relationships between transport properties such as thermal diffusivity and resistivity on the one hand, and the magnetic properties such as q profile and toroidal flux change on the other, in tokamaks that exist under macroscopically quasistationary conditions. It is experimentally well estab…

"Proposal for measuring magnetic fluctuations in tokamaks by Thomson scattering"

• F. A. Haas
• D. E. Evans