What is cusp confinement in fusion reactors?

[David lopez]

i have researched fusion reactors. i can't find a straight answer. what is cusp confinement.

 

[sophiecentaur]

Does the context help in what you have read. Show us a passage with the term i.

 

[David lopez]

In high beta conditions, the machine may operate with cusp confinement.[16] This is an improvement over the simpler magnetic mirror.[17] The MaGrid has six point cusps, each located in the middle of a ring; and two highly modified line cusps, linking the eight corner cusps located at cube vertices. The key is that these two line cusps are much narrower than the single line cusp in magnetic mirror machines, so the net losses are less. The two line cusps losses are similar to or lower than the six face-centered point cusps.[1 this passage is from wikipedia. So what is cusp confinement?

 

[sophiecentaur]

@David lopez I know very little about containing plasmas (my only contact with that was a visit to Fulham Labs when at University and a glimpse of Zeta, in the corner of a store room. However, the basics are that you produce a non-uniform field that traps plasma particles within a range of speeds. You will have read all about the Magnetic Mirror (I would hope), if you have searched plasma containment. In the middle of the main Wiki article there is mention of cusps and there is a link to the Biconic Cusp which has a diagram.
I found that after only five minutes of searching and I am sure that, if you decide to be non-specific in your search requirements, you will be able to home in on a statement about the way cusps manage to contain plasmas.
If you want information out of the system, you need to learn the art of teasing it out. You are very unlikely to find a perfect hit at the top of your first list that Google gives you so you try and try again. PF can be helpful but it really is up to you to do the basic research first.

 

[jartsa]

Here is a demonstration that shows that a superconducting object bounces off of a permanent magnet:

And here we have two electro- magnets, one on the left and other one on the right. See the picture:
https://en.wikipedia.org/wiki/Biconic_cusp
If we put a superconducting object between those two magnets and gave it some horizontal speed, it would bounce between the magnets. If we gave it some vertical speed it would bounce up and down. I'm not sure what would happen if we gave it some speed in the diagonal direction.

A charged particle in vacuum behaves like a superconductor. Its motion is an electric current, and there is no resistance for its motion.Finally here we have three opposing magnet pairs, between which charged particles are supposed to bounce, preferably forever:
https://en.wikipedia.org/wiki/Polywell