The two hemispheres are electrically connected to each other and to an AC power supply, the ring is connected to the same AC supply but 180 degrees out of phase. Particles are charged and then injected into the trap, they are then alternately attracted to the ring and hemispheres causing them to oscillate and become trapped! As...
I must admit that the details of how the fields are coupled went over my head, but I found the rest of the video quite accessible. Professor Copeland is a joy to listen to, and Brady asks great questions as usual....