The color of magnets

Artists Nathalie Kalbach and Urii Guchenia at the Chicagoland Nathalie Studio created stained-glass artwork as a representation of the magnetic field inside the Muon g-2 experiment at Fermilab. The centerpiece of Muon g-2 is a 15-meter-diameter ring-shaped magnet through which particles called muons shoot round at high speed.

To do the experiment, scientists have to keep the magnetic field throughout the whole ring extremely uniform and check it regularly so they can make tweaks. Earlier this year, the scientists took one of many measurements of just how uniform the field was. Slices from around the whole ring were squashed into a 2-D map, and it’s this very map that is now immortalized in glass.

The different colors of glass represent the amount of imperfection in the field, with the red and blue areas showing the greatest nonuniformities. Although it looks as though there are huge variations in the field between the center and the edges, even the darkest colors in the map represent a discrepancy from the desired field strength of just two parts per million. And it’s getting even better.