What happens to the cold electrons from the puffed in fuel?
Posted: Mon Sep 03, 2007 1:33 pm
Okay this is my understanding to date of how Polywell fusion fuelling works. You use an electron gun to inject electrons into the central cathode giving them enough energy to overcome its radially repulsive force.
Then you "drop" in ions from outside the cathode to fuel the device, these autmatically fall towards the centre of the virtual cathode where with luck they fuse, failing that they go back and try again.
In practice I believe this "dropping" of ions is achieved by puffing gas into the outside of the electron cloud where it is ionised by fast electrons at the edge of the magnetic trap. However for every ion that is created from neutralising a neutral atom, you will create a slow electron without enough energy to penetrate to the central cathode, these electrons might nonetheless remain magnetically trapped, and even if they travel a shorter distance before escaping because they will be moving more slowly they might still remain there for a considerable period of time.
What happens to them?
I was thinking one possibility might be that they would cool the fast electrons so that they would no longer have sufficient energy to penetrate into the centre of the device, causing the negative charge distribution to expand radially and degrading the focussing of the ions.
Then you "drop" in ions from outside the cathode to fuel the device, these autmatically fall towards the centre of the virtual cathode where with luck they fuse, failing that they go back and try again.
In practice I believe this "dropping" of ions is achieved by puffing gas into the outside of the electron cloud where it is ionised by fast electrons at the edge of the magnetic trap. However for every ion that is created from neutralising a neutral atom, you will create a slow electron without enough energy to penetrate to the central cathode, these electrons might nonetheless remain magnetically trapped, and even if they travel a shorter distance before escaping because they will be moving more slowly they might still remain there for a considerable period of time.
What happens to them?
I was thinking one possibility might be that they would cool the fast electrons so that they would no longer have sufficient energy to penetrate into the centre of the device, causing the negative charge distribution to expand radially and degrading the focussing of the ions.