August 15, 2007 - Cosmic Telescope

Since we have now mapped out the Bases and their opperating ranges, we will proceed to find the best High Voltage opperating ranges of the Scintillators. We have set the Thresholds at 275 mV each and they wer set at a distance of 2cm apart. The Top Scintillator is connected to Base 1 and the bottom scintillator is connected to base 2. We began by setting both scintillators at a High Voltage of 1300 and measuring the counts. After this was done, one scintillator was set at a voltage of 1300 and the other's voltage was changed at increments of 50 down to 1100 and up to 1400. This opperation was performed for both scintillators.

Plateau of Top Scintillator
Time	HV on top scint.	HV on bottom scint.	Singles Count (on top)	Coinc. Counts	Coinc. per minute
30 min	1400	1300
30 min	1350	1300
90 min	1300	1300	7265	233	2.59
30 min	1300	1300	2462	87	2.33
30 min	1250	1300	1817	70	2.3
30 min	1200	1300	1129	69	2.37
30 min	1150	1300	535	71	2.37
30 min	1100	1300	174	21	0.07

Plateau of Bottom Scintillator
Time	HV on top scint.	HV on bottom scint.	Singles Count (on top)	Coinc. Counts	Coinc. per minute
30 min	1300	1300	2462	87	2.77
90 min	1300	1250	1817	70	2.36
30 min	1300	1200	1129	69	1.23
30 min	1300	1150	535	71	0.267
90 min	1300	1100	174	21	0.0667