ST

Symmetric Tokamak (ST) was the first tokamak in the US, designed and built at PPPL. The origin of the design of ST was the Model C stellarator. After results in T-3 revealed that heating was more successful in tokamaks than in early stellarators, the team at PPPL decided to change the stellarator configuration to a tokamak configuration.
The transformation required changes in the vacuum vessel geometry, changing from racetrack to a circular configuration. The magnetic coils were designed to produce magnetic fields between 3.5 and 4.5 T. After 5 months of extensive transformation, the ST finally started operations on May 1st, 1970. The ST quickly achieved similar results to T-3, which led to the end of the stellarator era at that time. ST achieved electron temperatures of 2.2 keV.