Description of a reference design tokamak for the Technology Test Assembly

Early conceptual studies for the Technology Test Assembly involved a reference conceptual design for a tokamak with superconducting toroidal field magnets. The TF magnet conductors are NbTi filaments in a copper matrix. The 24 TF coils and associated structure operate at 4--5 K and a maximum field (at the windings) of 75 kG. Principal dimensions of the machine are: TF coil bore, 1.8 x 2.4 m (oval); major radius, 2.25 m; plasma minor radius, 0.6 m. A preliminary but detailed cost estimate for the reference machine was prepared to serve as an anchor point for cost scaling for larger machines in subsequent TTA parameter studies