On July 14, the Mu2e Project achieved a significant milestone with the approval of Critical Decision 3, which authorizes start of full construction.

The forthcoming Mu2e experiment at Fermilab will kidnap muons and trap them in aluminum atoms. But what exactly happens when you shoot a muon at an aluminum foil? While Mu2e is under construction, its scientists are already getting some valuable answers from a smaller accomplice: AlCap.

This model of the Mu2e solenoids was made on a 3-D printer at the University of Virginia. The Mu2e solenoids will form a continuous magnetic channel that captures pions from a production target, form a secondary muon beam and provide a constant field for momentum analysis of 100-MeV electrons. The magnetic field varies from nearly 5 Tesla (at the far right) to 1 Tesla (at the far left). The Mu2e tracker and calorimeter reside inside the solenoid at the far left. 3-D printing technology makes it possible to fabricate detailed models for a fraction of the cost of a traditional scale model.