stellator

A stellator is a type of device used in plasma physics and nuclear fusion research designed to confine hot plasma using magnetic fields. Unlike tokamaks, which rely on a toroidal magnetic field produced by a central solenoid, stellators generate their magnetic confinement fields entirely through external coils arranged in complex configurations. Their primary purpose is to achieve controlled nuclear fusion reactions by maintaining plasma stability at extremely high temperatures.

The term "stellator" originates from the Latin word "stella," meaning star, referencing the star-shaped arrangements of magnetic coils that generate the confining magnetic field. These coils are typically arranged in intricate patterns around the plasma chamber, creating a helical magnetic field that twists around the plasma. This configuration helps reduce the need for a large, central solenoid and enhances the device's stability against certain plasma instabilities.

Stellators are valued for their ability to provide steady, continuous operation without the need for pulsing, which is common in tokamaks. Their design allows for better control over magnetic field geometries, potentially improving plasma confinement and reducing energy losses. However, the complexity of coil arrangements makes their construction and maintenance more challenging compared to simpler fusion devices.

Research into stellators has contributed to understanding magnetic confinement principles and improving fusion reactor designs. Notable variations include the stellarator and the heliotron, which are both types of stellator devices with different coil configurations and magnetic field structures. While not yet commercially viable, stellators continue to be an important area of investigation in pursuit of sustainable fusion energy.