Bootstrap Fraction

The share of plasma current the plasma generates itself, reducing external drive.

Bootstrap fraction

15.2%

The bootstrap fraction is the portion of the plasma current driven by the plasma's own pressure gradient rather than external systems. A higher fraction cuts the auxiliary power the machine needs. HYPERION's bootstrap fraction is 15.2% of its 9.66 MA.

Raising it is a standard efficiency lever, bounded by stability.

A higher bootstrap fraction means less external current drive and therefore lower recirculating power, so it is a direct efficiency lever bounded by stability. HYPERION's 15.2% bootstrap fraction reduces but does not eliminate the drive it needs, which is why it also relies on efficient beam and RF current drive for steady state.