05/13/2011 coincidence test

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Set up like that:

the distance between PS and n's PMT is abot 80 cm

The voltages and thresholds are as below. Note: I increased my thresholds for PS1 and PS2 from 80 mV up to 100 mV according to mu previous calibration threshold line.

	PMT voltage, V	threshold, mV	discr. width, ns
PS1	-1500	-80	100
PS1	-1500	-80	100
n's	-1500	-200	10

Let's do first the coincidence test PS1+PS2

	counts	time	counts/sec
PS1	2823[math]\pm[/math]53.1	20 min	2.35[math]\pm[/math]0.04
PS2	3091[math]\pm[/math]55.6	20 min	2.57[math]\pm[/math]0.05
PS1+PS2	93[math]\pm[/math]9.6	20 min	[math](7.7\pm0.8)\cdot 10^{-2}[/math]

The scope picture of PS1+PS2 coincidence event like: