PBX

The Princeton Beta Experiment (PBX) was an upgrade made to PDX at PPPL. Its objective was to produce plasma with higher β values than the obtained in conventional tokamaks by reducing some instabilities presented in other devices. This reduction was achieved by shaping its plasma cross section like a kidney bean, which also increased the plasma current capacity of the plasma. PBX was able to achieve β values of 5.3%, a record at its time. In 1986, PBX was shut down to be transformed into PBX-M.