Circular Orbit e/m

This kit lets students see the effect of electric and magnetic fields on an electron stream.

The large orbital electron path is circular, providing good visibility and accuracy (±5%). Helmholtz coils are built into the casing. The beam tube has a built-in, engraved glass rod with a centimeter scale along its central axis that eliminates parallax when making diameter readings of the electron orbit.
clearly marked connecting posts for the filament, heater and, coils eliminate student error. A provided hood can be slipped over the apparatus, so you can work without darkening the room.

The tube is 13 cm dia. 13 cm and uses helium. The kit has an accelerating potential of 100-550V, and heater has 6.3V. Power supplies are required but not included.