Question about Magnetism, Gravity and Fusion Reactors

[JohnSSM]

Regarding the Tokamak reactors they are using in Germany to create fusion, I had a couple questions.

If fusion, in stars, is catalyzed by huge gravitational pressures within objects massive enough to create fusion, are they using magnetic fields to essentially contain that amount of pressure in the Tokamaks? Is this how the plasma is enabled to reach the temperatures it needs to become a plasma? They have to contain it, yes? And not only contain it, but contain it with the same amount of force that you would encounter within the gravitational pressures of stars? And they do this with magnetic fields in specific geometrical shapes?

Does that at all describe what is happening within these fusion reactors?

Amendments, corrections or additions? Thanks much.

[mathematic]

https://en.wikipedia.org/wiki/Tokamak

 

See above

[Enthalpy]

Essentially, yes. The plasma must have some density so that collisions of D and T happen often enough:

- So often that the produced fusion energy exceeds the heat radiated by the plasma

- So long that the produced energy exceeds what was invested to heat the plasma first

it can be thought in words of pressure, even "magnetic pressure", but this isn't very fertile.

 

In stars, the plasma density is much higher than a Tokamak can achieve. As well, a star takes for instance 10 billion years to burn a part of its hydrogen, which Sapiens won't wait with their reactors. So Tokamaks use a much higher temperature (10⁷K rather than 10⁶K) to achieve a faster reaction despite the lower density, and seek the easiest reaction: D-T (despite we have no abundent tritium at hand).

 

A true Tokamak does it with rather simple shapes of magnetic field. To my eyes (I'm no expert for that!) it resembles a storage rig with dipoles only.

 

The Wendel-X in Germany is a bit different, called a Stellarator. Its magnetic field has an intricated shape, as the coils already tell. I imagine (again, no expert!) that some components of this field have the same function as the quadrupoles of a storage ring: they bring back to the torus' center the particles that oscillate too much away.

 

Please take with mistrust. I don't even know how the lateral oscillation of the particles is damped in a storage ring: the quadrupoles would only bring them to the center but not reduce their transverse speed. If someone knows, thanks! Fusion reactors may well have similar features already.