Before revision: Quasi-isodynamic (QI) stellarators are a class of magnetic confinement fusion reactor which satisfy the property of omnigeneity, avoid the potentially hazardous toroidal bootstrap current, and have minimal neoclassical transport in the collisionless regime.
After revision: A quasi-isodynamic (QI) stellarator is a type of magnetic confinement fusion reactor that satisfies the property of omnigeneity, avoids the potentially hazardous toroidal bootstrap current, and has minimal neoclassical transport in the collisionless regime.