"The "focused doughnut", a single-cycle electromagnetic perturbation of toroidal topology with inseparable time and spatial dependencies propagates at the speed of light in vacuum, as was shown by Hellwarth and Nouchi in 1996. While normal incidence reflection and refraction of conventional electromagnetic pulses in isotropic media do not lead to polarization changes, "focused doughnut" pulses ...

The first sustainment of toroidal plasma current of 50 kA at up to 3 times the injected currents, added in quadrature, using steady inductive helicity injection is described. Separatrix currents-currents not linking the helicity injectors-are sustained up to 40 kA. Decreases in the n=1 toroidal mode of the poloidal magnetic field at higher current amplifications indicate more quiescent, direct ...

It is shown that when tokamaks are perturbed the kinetic energy principle is closely related to the neoclassical toroidal torque by the action invariance of particles. Especially when tokamaks are perturbed from scalar pressure equilibria, the imaginary part of the potential energy in the kinetic energy principle is equivalent to the toroidal torque by the Neoclassical Toroidal Viscosity (NTV)....

Understanding the properties of the internal magnetic field of neutron stars remains a theoretical challenge. Over the last years, twisted-torus geometries have been considered both in Newtonian and general-relativistic equilibrium models, as they represent a potentially good description of neutron star interiors. All of these works have found an apparent intrinsic limitation to geometries that...

Abstract A three-mode model for the resistive wall modes based on the toroidally coupled resistive wall tearing modes is developed. The linear neoclassical tearing mode response is used at the singular surfaces to enhance plasma inertia and reduce the toroidal rotation speed for stability. The dispersion relation is obtained from the determinant of a 6×6 matrix. The toroidal rotation profile fo...

I gave two talks on some of my results on toroidal Lie algebras in the conference Functional Analysis VIII held in Dubrovnik, Croatia in June 2003. But these results have been submitted to research journals and will appear soon. So I decided to write an expository article on Toroidal Lie Algebras covering my results for the proceedings of Functional Analysis VIII. I will introduce the definitio...

Ah&z&-Diagonal and toroidal mesh are degree-4, point to point intercoimection models suitable for connecting communication elements in parallel computers, particularly multicomputers. The two networks have a similar structure. The toroidai mesh is popular and well-studied whereas tbe diagonal mesh is relatively new. In this paper, we show that the diagonal mesh has a smaller diameter and a larg...

In this paper we propose transformer-based solutions to several power quality problems. Elsewhere we have shown how to solve the acoustical noise emission problems. In this paper we introduce toroidal transformers with reduced inrush currents, transformers with reduced electromagnetic emissions, and other transformers useful to reduce the transfer of harmonics. With the low-inrush transformers ...

Resistive MHD is used to examine bulk plasma flows in the limiter shadow region of Alcator C. Expressions for the Pfirsch-SchlUter perpendicular plasma flow velocities are obtained for a toroidal system in which the pressure profile depends on radius only. Data from Langmuir probe measurements in the shadow of the limiter is used to estimate the magnitude of this plasma convection. Because of t...

Predictive transport simulations of tokamak discharges are continuously improving thanks to increasing computational resources available and to the efforts made in code development. As an example of the progress, a recent work [1] with the Elmfire code demonstrates the ability of global gyrokinetic full f electrostatic particle simulations, including both neoclassical and turbulence physics, to...