UKAEA Papers

"Adiabatic invariants and the equilibrium of magnetically trapped particles"

• RJ Hastie
• JB Taylor
• FA Haas

"Maximum plasma pressure for stability in magnetic fields with finite minima"

• JB Taylor
• RJ Hastie

"On Energy Confinement following the Onset of 'Stiff ' Transport and the Effect of Radiation"

• J W Connor
• R J Hastie
• K Richards

"Ion Landau Damping and Drift Tearing Modes"

• J W Connor
• C J Ham
• R J Hastie
• A Zocco

Kinetic treatments of drift tearing modes that match an inner, resonant layer solution to an external MHD solution, can fail to match the ideal MHD boundary condition on the parallel electric field. In this paper we demonstrate how consideration of ion sound and ion Landau damping effects achieves this, placing the theory on a firm footing. The …

"A One-Dimensional Tearing Mode Equation for ELM Studies in Tokamaks."

• JW Connor
• RJ Hastie
• C Marchetto
• CM Roach

Starting from expressions in Connor et al. (1988), we derive a one-dimensional tearing equation similar to the approximate equation obtained by Hegna & Callen (1994); Nishimura et al. (1998), but for more realistic toroidal equilibria. The intention is to use this approximation to explore the role of steep H-mode pedestals, bootstrap currents a…

"Neoclassical, Semi-collisional Tearing Mode Theory in an Axisymmetric Torus"

• J. W. Connor
• R. J. Hastie
• P. Helander

A set of layer equations for determining the stability of semi-collisional tearing modes in an axisymmetric torus, incorporating neoclassical physics, in the small ion Larmor radius limit is provided. These can be used as an inner layer module for inclusion in numerical codes that asymptotically match the layer to toroidal calculations of the teari…

"The Effect of Plasma Beta on High-n Ballooning Stability at Low Magnetic Shear"

• J.W. Connor
• C.J. Ham
• R.J. Hastie

An explanation of the observed improvement in H-mode pedestal characteristics with increasing core plasma pressure or poloidal beta, pol b , as observed in MAST and JET, is sought in terms of the impact of the Shafranov shift, D¢ , on ideal ballooning MHD stability. To illustrate this succinctly, a self-consistent treatment of the low magnetic she…

"The Role of Thermal Conduction in Tearing Mode Theory"

• J.W. Connor
• C.J. Ham
• R.J. Hastie
• Y.Q. Liu

The role of anisotropic thermal diffusivity on tearing mode stability is analysed in general toroidal geometry following similar techniques to Glasser et al [A H Glasser, et al, Phys. Fluids 18 (1975) 875], although a stronger ordering of the plasma compressibility is required. Resistive layer equations are obtained for a resistive MHD model with a…

"High-m Kink/Tearing Modes in Cylindrical Geometry"

• J.W. Connor
• R.J. Hastie
• I. Pusztai
• P.J. Catto
• M. Barnes

"Tearing mode Stability Calculations with Pressure Flattening"

• C.J. Ham
• J.W. Connor
• S.C. Cowley
• R.J. Hastie
• T.C. Hender
• Y.Q. Liu

Calculations of tearing mode stability in tokamaks split conveniently into an external region, where marginally stable ideal MHD is applicable, and a resonant layer around the rational surface where sophisticated kinetic physics is needed. These two regions are coupled by the stability parameter △'. Pressure and current perturbations local…