[Fusion] Basic concept behind the Stellarator

[Meaning]

Hey

I am starting a course on plasma physics, I don't understand the principle of Stellarators.

If there is no plasma current, how is the mhd equilibrium achieved (J \times B = grad P)?

I apologize if the answer is obvious, but I starting with this

 

[artis]

@Meaning Well the answer is by no means obvious.

Well as far as I know they achieve the MHD equilibrium with the geometry of the field. That is why the stellarator looks like a weird twisted and warped ring. This is the reason why you need toroidal and poloidal(plasma induced current) and vertical balancing fields in a symmetrical torus like a tokamak, otherwise the plasma tends to expands outward , form islands of charge and eventually hit the walls.