The S-shaped Mu2e transport solenoid is divided into two halves. Muons travel down the first half of the curvy corridor, where they are separated by charge. At the solenoid’s midway point, they encounter a special device that permits only negatively charged muons to pass through to the second curved section. The negative muons then exit the transport solenoid and enter the next big magnet, the detector solenoid (the larger cylinder on the right). There, they stop in a second target. Image: Mu2e