Confining Charged Particles with Alternating Electrostatic Fields

[Drakkith]

Is it possible to use an alternating/rotating electrostatic method to confine charged particles?

For example, if you want to confine electrons inside a cube, could you use a negative charge that is alternated between each side at a time, on a timescale of nanoseconds between each alternation?

 

[Andrew Mason]

Is it possible to use an alternating/rotating electrostatic method to confine charged particles?

For example, if you want to confine electrons inside a cube, could you use a negative charge that is alternated between each side at a time, on a timescale of nanoseconds between each alternation?

Why not put negative charge on all sides of the cube?

AM

 

[Drakkith]

Why not put negative charge on all sides of the cube?

AM

From what i understand, it would be similar to a charged hollow sphere, and the combined charge all at once would cancel itself out inside the sphere. The closer a particle gets to a wall, the more of the sphere or cube is on the other side of it, which cancels out the field on the other side. At least, that's they way I understood from reading it somewhere.

 

[Andrew Mason]

From what i understand, it would be similar to a charged hollow sphere, and the combined charge all at once would cancel itself out inside the sphere. The closer a particle gets to a wall, the more of the sphere or cube is on the other side of it, which cancels out the field on the other side. At least, that's they way I understood from reading it somewhere.

That is correct - for a sphere. But a cube is not a sphere. The force inside a cube that has a uniform surface charge density is the superposition of the forces between three sets of uniformly charged plates positioned at right angles to each other. I would think that the force would be 0 only in the middle.

AM

 

[Drakkith]

That is correct - for a sphere. But a cube is not a sphere. The force inside a cube that has a uniform surface charge density is the superposition of the forces between three sets of uniformly charged plates positioned at right angles to each other. I would think that the force would be 0 only in the middle.

AM

I think the corners would be the weak point in this. As a particle gets close to the corner, there is more and more of the cube on the other side of it, similar to what happens in a sphere. Does that sound correct?

 

[Aezi]

There is a way to confine a charged particle by using a "magnetic bottle". I can't find any good online sources regarding it, but basically a compound magnetic field created by two coils can make charged particles with proper velocities simply spiral repeatedly from one end to the other.

 

[Drakkith]

There is a way to confine a charged particle by using a "magnetic bottle". I can't find any good online sources regarding it, but basically a compound magnetic field created by two coils can make charged particles with proper velocities simply spiral repeatedly from one end to the other.

Yep. I'm wondering about an electrostatic field though.