Typical Histograms

A typical beam spot should be centered near (0,0), representing a muon beam traveling through the middle of the detector. Figures 1 and 2 show upstream and downstream beam spots which are concentrated a little below the center of the detector. This is due to the alignment of the detector ~2mm above the magnet center. The beam spot contains events caused by all particles. Upstream, the well defined center is created by the dominance of incoming muons with relatively straight tracks. Downstream, the beam is less concentrated as a large percentage of the particles are positrons following helical tracks. The grated look occurring at positions larger than ~5cm is an effect of the multiplexed PC planes used to create the beam spot histograms.