Compact magnetic confinement fusion: Spherical torus and compact torus

Abstract

The spherical torus (ST) and compact torus (CT) are two kinds of alternative magnetic confinement fusion concepts with compact geometry. The ST is actually a sub-category of tokamak with a low aspect ratio; while the CT is a toroidal magnetic configuration with a simply-connected geometry including spheromak and field reversed pinch. The ST and CT have potential advantages for ultimate fusion reactor; while at present they can also provide unique fusion science and technology contributions for mainstream fusion research. However, some critical scientific and technology issues should be extensively investigated.

Development of a compact torus injection system for the Keda Torus eXperiment

“…The CT penetration condition expressed in equation (1) indicates that a high density and high velocity CT is required. In order to achieve breakdown and form high density CTs, high gas pressure in the formation region is required.…”

“…A compact torus (CT) is a donut-shaped plasmoid confined by nested helical magnetic field lines surrounding the torus, similar to the field line structure in a spheromak plasma [1]. The toroidal and poloidal magnetic field components of similar magnitudes are induced entirely by the helical plasma current flowing in the plasma itself.…”

Adiabatic plasma rotations and symmetric magnetohydrodynamical stationary equilibria: analytical and semi-numerical solutions

“…The analytical and semi-numerical solutions we obtained in this work can be regarded as simplified models for compact tori. Unfortunately neither can model a spherical tokamak, though, since the toroidal field is not generated by external coils, nor spheromaks since the toroidal fields do not vanish at the plasma edge [27]. Therefore the configurations we considered could be more aptly called 'plasmoids', according to the general usage of this term.…”