The Centre-Column Challenge

Why the slim central column is the defining engineering problem of a spherical tokamak.

Aspect ratio

2.5

Challenge

Slim, highly-loaded centre column

A spherical tokamak's low aspect ratio (A = 2.5) leaves very little room at the machine centre for the toroidal-field conductor, central solenoid, and shielding. Fitting the field, current and neutron protection into that slim column — while carrying huge forces — is the defining engineering challenge Kronos's breeder design confronts head-on.

It is a real, named focus of the design rather than an afterthought.