Princeton Large Torus

The Princeton Large Torus was a very early tokamak plasma fusion device built at the Princeton Plasma Physics Laboratory.

It was the first tokamak with a plasma current over 1 MA.

The PPPL website says:

1975:The Princeton Large Torus (PLT) begins operation on December 20. PLT experiments are expected to give a clear indication whether the tokamak concept plus auxiliary heating can form a basis for a future fusion reactor.

1978: In July, PLT sets a world record for ion temperatures of 60 million degrees C using neutral-beam heating. For the first time, ion temperatures exceed the theoretical threshold for ignition in a tokamak device.

1981:PLT produces the first tokamak discharge in which the plasma current is driven entirely by lower-hybrid radio-frequency waves.

1984:PLT uses ion-cyclotron radio-frequency heating to produce ion temperatures of 60 million degrees C, a record for this technique.

says "Largely a copy of the Russian T-10, but with addition of NBI and LH systems. Demonstrated current drive from breakdown by LH, but that LH only effective in low density plasmas. Variable minor radius by adjusting limiter position. The first machine to achieve a plasma current of 1MA. Metal limiters replaced by carbon limiters ... about 1978."

RF heating :

...
Wikipedia