Model C stellarator
The Model C stellarator was the first large-scale stellarator to be built, during the early stages of fusion power research. Planned since 1952, construction began in 1961 at what is today the Princeton Plasma Physics Laboratory (PPPL). The Model C followed the table-top sized Model A, and a series of Model B machines that refined the stellarator concept and provided the basis for the Model C, which intended to reach break-even conditions. Model C ultimately failed to reach this goal, producing electron temperatures of 400 eV when about 100,000 were needed. In 1969, after  UK researchers confirmed that the USSR's T-3 tokamak was reaching 1000 eV, the Model C was converted to the Symmetrical Tokamak, and stellarator development at PPPL ended. Design parameters. The Model C had a racetrack shape. The total length (of the tube axis?) was 1.2m. The plasma could have a 5-7.5 cm minor radius. Magnetic coils could produce a toroidal field (along the tube) of 35,000 Gauss. It was only capable of pulsed operation. It had a divertor in one of the straight sections. In the other it could inject 4 MW of 25 MHz ion cyclotron  resonance heating (ICRH). It had helical windings on the curved sections. Results. An average ion temperature of 400 eV was reached in 1969. History. Construction funding/approval was announced in April 1957 with the design based on Katherine Weimer's efforts in fundamental research. It started operating March 1962. The Model C was reconfigured as a tokamak in 1969, becoming the Symmetric Tokamak (ST).