Introduction
1. There is an easy way to fuse atoms. It is called a fusor. The Polywell is a re-imagined fusor.
2. The fusor uses to wire cages, one inside the other, to fuse atoms.
3. A negative voltage is applied between the cages.
4. When positive ions enter the cage they fall towards the center. If they hit in the center, they can fuse. The electric field is doing work on the ions heating them to fusion conditions.
Part 1: The Machine
1. The Polywell is a new kind of fusor. Instead of a cage, it traps electrons using six electromagnets in a box.
2. There are four interesting points in these machines: the axis (pause) the corner (pause) the joint (pause) and the center.
3. Each ring is a coil of copper wiring inside a smooth steel shell. These are electromagnets. Each has a north and south pole.
4. Each pole faces into the center.
5. This is an image of the magnetic field.
6. This creates a magnetic field pressure inside the rings. This pressure can contain electrons and ions. Tokomaks use similar fields.
7. Outside the rings is a cage.
8. This cage is charged negative to the rings.
9. When everything is switched on there is a magnetic and electric field inside the machine.
Part 2: Operation
1. Once the fields are working, electrons are released. They fly towards the rings.
2. The magnetic fields overpower the electric fields and the electrons are caught.
3. They start to corkscrew along the magnetic field lines and pass into the center. In the center there is a null point which can scatter them. They head to the corners and hit a dense field. They are reflected and trapped.
4. Electrons move back and forth inside the rings. They move straight through the null point in the center. As they move they lose energy as light.
5. Overtime electrons are lost. Extending trapping is key challenge.
6. When billions of electrons are trapped they make a negative cloud in the center. This cloud may look like a 14 point star. Each "spike" in the star would be pointed to the sides and corners of the rings.
7. This cloud makes a large electric field. This field accelerates ions to fusion conditions. When the ions hit in the center they can fuse.
8. Once electrons are trapped, Deuterium gas is puffed in. Because it is uncharged, the gas crosses to the rings without problems.
9. When it reaches the edge of the cloud it exchanges energy with the electrons. It ionizes. The ion falls towards the center. When they hit, they can fuse. The electric field is doing work on the ions. It heats them to fusion conditions.
Part 3: Considerations
1. The machine loses energy by conduction. This is when mass touches a metal surface and is conducted away. The energy leaves with the mass.
2. The machine losses energy by radiation. This is when energy leaves the center as light.
3. As the plasma heats up it loses more energy as light.
4. One way to reduce radiation losses is keeping the electrons cold and the ions hot. But how this will work is unknown.
5. Energy can be captured using the heat cycle or direct conversion. Direct conversion is a new way to capture energy. It has shown a 48% efficiency.
6. Each of these rates can be combined into the equation for net power. This equation will drive these machines.
7. This idea is very new. Many problems and unknowns remain. Much more research is needed.
8. We need to control ion focus, acceleration or formation. A millimeter to the left or right and the ion experiences a completely different acceleration. Methods for control are not fully understood.
9. A third problem is well preservation. The positives and negatives like to mix together. This makes it hard to concentrate all the charge in one place. This means holding the electric field needed for fusion is hard to do, overtime.
Part 4: Frequently Asked Questions
Question: Won't the ions and electrons recombine?
Answer: The ionization energy of deuterium is 16 eV. As long as the plasma is hotter than that it will remain fully ionized.
Question: Is there a limit to how much charge you can fit in the center?
Answer: Yes, there is. It is called the Brillouin limit. It places a limit as to how many net electrons we can pack in the center. But so far, these machine have not come close to the limit.
5. Question: Why can’t you simulate this?
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6. Answer: billions of electrons behave very differently than a single electron. Simulations need to be improved to deal with this.
Part 5: Conclusions
1. These and many other problems face the Polywell. Lots of work is needed to figure out if this can be a cheap source for green energy. Thanks for watching!