CDX

The Current Drive Experiment (CDX) was a device located at PPPL. It was an upgrade of ACT-1 made to explore current drive and current profile control methods. CDX was the first tokamak to use the DC helicity injection concept (a method to continuously inject electrons to maintain the plasma current) to initiate and maintain the plasma discharge. In 1989 CDX was upgraded into CDX-U to explore the helicity injection in a small aspect ratio device.