Stellarator

Stellarator is a type of plasma confinement device used in fusion power to trap high temperature plasma using magnetic fields. The stellarator is one of the earliest controlled fusion devices, invented by Lyman Spitzer in 1951 and built the following year at what later became the Princeton Plasma Physics Laboratory.

History

The stellarator was invented by Lyman Spitzer in 1951 and built the following year at what later became the Princeton Plasma Physics Laboratory. The name "stellarator" comes from the Latin word for star, "stella". The device was named for its ability to confine star-like plasma.

Design

The stellarator attempts to create a natural magnetic bottle configuration using only external magnetic fields. Its design uses a series of twisted coils to generate a toroidal (doughnut-shaped) magnetic field across the plasma, effectively confining it.

Operation

In a stellarator, the plasma is confined in a toroidal shape (a doughnut shape) but with a twist. The twist is necessary to prevent plasma from escaping from the magnetic confinement. The plasma is heated to high temperatures, and the pressure of the hot plasma is balanced by the magnetic field.

Advantages and Disadvantages

The main advantage of the stellarator design is its steady state operation. Unlike the tokamak, which requires a large current drive and pulsed operation, the stellarator can operate continuously. This makes it a strong candidate for a practical fusion power plant.

However, the complex coil design makes the stellarator more difficult and expensive to build and maintain than other designs. The plasma confinement is also less efficient than in a tokamak, leading to higher losses and lower performance.

Examples

Examples of stellarators include the Wendelstein 7-X in Germany, the largest stellarator in the world, and the Helically Symmetric Experiment (HSX) in the United States.

See also

• Magnetic confinement fusion
• Tokamak
• Fusion power
• Plasma physics