Plasma Current

The toroidal current a tokamak drives through its plasma; it confines and shapes the plasma.

Breeder current

9.66 MA

Bootstrap fraction

15.2%

The plasma current is the electric current driven around the torus; its poloidal magnetic field is essential to confinement and shaping. HYPERION runs 9.66 MA of plasma current, split between a self-generated bootstrap fraction (15.2%) and externally driven current.

The current is limited from above by stability (via the safety factor and Greenwald density) and costs auxiliary power to sustain — both captured in the design point.

The plasma current does double duty: its poloidal field is essential to confinement, and its profile shapes stability through the safety factor. Sustaining 9.66 MA indefinitely in steady state means combining the 15.2% bootstrap fraction with efficient external drive — the balance that keeps the recirculating power low.