Model B-3

Model B-3 was the last device made with a figure-eight configuration in PPPL. As most of the Model Bs, it was made using 5cm diameter tubes. It was used to study confinement of ohmically heated plasmas and included helical windings, a divertor, and a gas purification system. The helical coils didn't improve the confinement and due to "pump-out", confinement time was only a few microseconds. These results confirmed that the actual confinement was lower than classical predictions and phenomena like pump-out needed further research.

The results of the Model B-3's ion-cyclotron heating and the general data gained about stellarator operating conditions led to the construction of Model B-66.