WISRD Research & Engineering Journal

Figure 10 . Plateauing channel one using channel two as a fixed voltage (Ch 4 - .803). After plateauing the channels, the potentials across each PMT were set. The final check was made by examining histograms created from counts vs time over threshold for the counters as seen in Fig. 11; these curves indicate a result that we consider a successful calibration as they are symmetrical and centered a little over 20 ns.

Figure 11 . Histogram visualizing time over threshold for the four channels. 5. Preparing the Physical Detectors The physical detectors had to be light proofed, kept dry, and protected from the extra heat of being placed on a roof in Los Angeles, California.

Figure 12 . WISRD members designing and building weather proofed boxes for scintillators. Each scintillator with PMT was wrapped in black garbage bags, black theater spotlight paper, and black tape and placed in a box built in the lab using 2x4’s and ¼” plywood (Figs. 12 and 13). As the photomultiplier for the scintillator is extremely sensitive to light, the only light that can be allowed inside is the very low intensity light produced when the incoming muons penetrate the scintillator. This light produced by the muon needs to be isolated from all other light sources to ensure that the light observed and recorded is being produced from a muon interaction, and contamination from other light sources is excluded.

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