We will upgrade some of the CSP and the CMX, but the BSU is all brand new. The scintillating chemicals used to dope the plastic muon detectors release photons when energized by a high-energy muon passing through the detector. Over time the passage of the photons to the PMT decreases due to loss of transparency of the plastic of which the muon detector is made. Trigger 1 Muons LED Fiber Figure 1. The first test we do is to find out if there are any light leaks in the scintillator by using a picoammeter to measure the dark current.
Dark current is the electric current caused by background noise.
If there are any light leaks there will be large dark currents in our system. The four other tests are known as the pedestal, calibration, attenuation, and plateau tests. The pedestal refers to background noise produced by the experimental setup, and by recording the magnitude of the pedestal we can subtract it from measurements to find the results we wish to obtain, without any effects from the background noise. Having found out the background noise, we then proceed to calibrate our system. Since each PMT will have different characteristics, there will be a need to calibrate each one separately.