Below are some nice pictures the ATLAS detector took of muons created in the atmosphere that passed through Meyrin, Switzerland on July 21, 2008 (or technically “Event Displays from M8 Week”). The lines are the paths the muons took through the ATLAS detector, according to the reconstruction software. You can see the detector elements that actually recorded something are lit up along those paths. The reconstruction software “connects the dots”.
In each image are several views from different perspectives, or projections. The top projection in each image is the view down the beam axis, sort of what will be the “proton’s eye view” during collisions. The one below that is the view from alongside the detector.