5 fast facts about the doughnut-shaped fusion reactor

Tokamaks use powerful magnetic fields to confine plasma in a doughnut shape called a torus.

To initiate fusion, the plasma must be heated to temperatures exceeding 100 million degrees Celsius.

Net energy is hard because reactors must overcome plasma turbulence and maintain extreme stability.

The ITER central solenoid will be the largest superconducting magnet ever built.

Misconception: Many believe fusion is a runaway reaction, but it is intrinsically impossible.