Concepts

Induction, superconductivity, magnetic fields from currents

Overview

A pair of superconducting slugs embedded in a styrofoam train will float above a magnetic track when the slugs are cooled to the boiling point of liquid nitrogen. The train moves around the track with only air friction slowing it down.

Details

Equipment

• [1] Superconducting train
• [1] Magnetic track
• [1] Small dewar of liquid nitrogen
• [1] Styrofoam cup
• [1] Aluminum plate
• [1] Sheet of paper

Safety Equipment

• [1] Safety goggles
• [2] Safety glove

Classroom Assembly

1. Place the track somewhere visible and away from ferromagnetic objects.
2. Put the aluminum plate on the magnetic track.
3. Put the superconducting train on top of the plate.

Important Notes

• Liquid nitrogen can cause frostbite, blindness, and asphixiation. Handle with care in well-ventilated areas.
• The superconductor is a ceramic containing heavy metals, which are poisonous. Wash your hands after use.
• Cooling the train at a slightly elevated position is essential.
• The magnets are strong. Handle with care.

Script

1. Put on your safety goggles and gloves.
2. Pour some liquid nitrogen from the dewar to the cup.
3. Use the styrofoam cup to cool the superconductors with liquid nitrogen until rapid boiling in the train stops.
4. Top up the liquid nitrogen level in the train.
5. Give the train a gentle tap to make it go around the track.
6. Remove the aluminum plate.
7. Place a sheet of paper underneath the train to show it is floating on the track.

Additional Resources