  A new burn control scheme for tokamaks is described where the total fusion
power is controlled by adjusting the plasma volume fraction that is packed into
power dense regions. In an example spherical tokamak burning plasma, by
modifying the plasma edge squareness the total fusion power is doubled at
almost constant total plasma volume and fusion power density. Therefore,
increased plasma squareness could be extremely beneficial to a fusion reactor
and squareness control could be desirable for power load balancing. Experiments
have observed the impact of increased edge squareness on modified core plasma
volume, highlighting the practical relevance of this approach.
