Linear Quadropole Trap Design

Levitating charged particles can be accomplished relatively easily with the use of a high-voltage AC power supply and simple electrodes1.

Simple Paul trap For the above demonstration of the principle of these "Paul" traps, I used a variac and a neon sign transformer along with two spherical brass electrodes and a copper ring. Lycopodium spores were used as a convinient charged particle, which can be seen levitating between the electrodes.

Linear Paul trap Linear trap design. See this page for. Machined plastic holds 4 off-the-shelf metal rods (from an optical cage system) as well as two brass endcap electrodes.

Paul trap endcap Encap viewed from inside.

Linear Paul trap with cables. System with cables installed.

Trapping particles in a linear Paul trap Trapping large numbers of charged particles (lycopodium spores). Click for larger image.

Manipulating trapped particles in a linear Paul trap. Particles manipulated into a cloud with a q-tip and plastic pipet.

Linear chain of particles in a linear Paul trap. Trapping a linear chain of particles. The particles have a small periodic motion due to the oscillating trapping fields.

Vortex forming in a linear Paul trap. When the density of the particles is high, dynamics vortices can form, spinning rapidly.

  1. Winter, H., & Ortjohann, H. W. (1991). Simple demonstration of storing macroscopic particles in a ‘‘Paul trap’’. American Journal of Physics, 59(9), 807-813.