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torus
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A torus is shown with three labeled loops: one encircling the central hole (a), one passing through the hole (b), and one small loop on the surface (c), illustrating concepts in general topology.
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torus

physics
Also known as: doughnut
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A torus is shown with three labeled loops: one encircling the central hole (a), one passing through the hole (b), and one small loop on the surface (c), illustrating concepts in general topology.
The torus is not simply connected. While the small loop c can be shrunk to a point without breaking the loop or the torus, loops a and b cannot because they encompass the torus's central hole.

In physics, a torus is a doughnut-shaped surface generated by rotating a circle around an axis in its plane that does not intersect the circle. This shape is also referred to as a toroid. The term "toroidal" describes something that is related to, or shaped like, a torus.12

In the context of fusion reactors, toroidal confinement is a key concept. Devices like tokamaks use a toroidal magnetic field, which has components spiraling both the long and short way around the torus, to contain plasma. This helical magnetic field is essential for maintaining the plasma in a stable equilibrium, preventing it from drifting to the walls of the machine.3

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4 Britannica Sources
  1. torus
  2. fusion reactor - Toroidal confinement
  3. tori
  4. toroidal

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