05/13/2011 coincidence test

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Revision as of 16:35, 16 May 2011 by Shaproma (talk | contribs)
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Set up like that:

Detector1.png


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

PMT voltage, V threshold, mV discr. width, ns
PS1 -1000 -100 50
PS1 -1000 -100 50
n's -1500 -200 10



First let's do the PS1+PS2 coincidence test. The distance between PS and n's PMT is about 80 cm

The distance between PS and n's PMT is about 80 cm
counts time counts/sec
PS1 [math]2823\pm53.1[/math] 20 min [math]2.35\pm0.04[/math]
PS2 [math]3091\pm55.6[/math] 20 min [math]2.58\pm0.05[/math]
PS1+PS2 [math]93\pm9.6[/math] 20 min [math](7.7\pm0.8)\cdot 10^{-2}[/math]

The distance between PS and n's PMT is about 50 cm

counts time counts/sec
PS1 [math]7513\pm86.5[/math] 60 min [math]2.09\pm0.02[/math]
PS2 [math]9036\pm95.1[/math] 60 min [math]2.51\pm0.03[/math]
PS1+PS2 [math]251\pm15.8[/math] 60 min [math](6.9\pm0.4)\cdot 10^{-2}[/math]



The scope picture of PS1+PS2 coincidence event like:

Cosmic coinc PS1 PS2.png



Second tet's do the PS1+PS2+n's coincidence test

counts time counts/sec
PS1 [math]3229\pm56.8[/math] 20 min [math]2.69\pm0.05[/math]
PS2 [math]3192\pm56.5[/math] 20 min [math]2.66\pm0.05[/math]
PS1+PS2+n's [math]59\pm7.7[/math] 20 min [math](4.9\pm0.6)\cdot 10^{-2}[/math]


The scope picture of PS1+PS2 coincidence event like:

Cosmic coinc PS1 PS2 n.png


The ratio of (PS+PS2) rate to (PS+PS2+n's) rate is

[math]\frac{7.7}{4.9} = 1.6[/math]