05/12/2011

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The powers are:

PS1 and PS2:  -1000 V (the old 2-channel TENNELEC TC952)
n's: -1100 V (the new 2-channel C.A.E.N N471)

The thresholds are:

PS1 and PS2:  -80 mV
n's: -200 mV

The discriminator widths are:

PS1: -20 ns
PS2: -10 ns
n's: -20 ns

Let's do the random coincidence cosmic ray test. PS1 and PS2 is about 30 cm away from each other. And let's look on the coincidence signal between PS1 and PS2:

	total counts	time	counts/min	counts/sec
PS1	[math]10247\pm101.2[/math]	70 min	[math]146.4\pm1.44[/math]	[math]2.44\pm0.02[/math]
PS1	[math]12969\pm113.9[/math]	70 min	[math]185.3\pm1.63[/math]	[math]3.09\pm0.03[/math]
PS1+PS2	[math]3\pm1.7[/math]	70 min	[math]0.043\pm0.024[/math]	[math]0.0007\pm0.0004[/math]

And below my scope pictures of this rear event:

Let's do the 2n correlation test with CF252 source. The voltages and thresholds are the same. Set up is like that:

the distance between PS1 and PS2 is 12.5 cm and they faced to the source

the CF252 source in the middle

Below are the total number of events (2n fission events + random coincident):

	total counts	time	counts/min	counts/sec
PS1	[math]255977\pm505.9[/math]	10 min	[math]25597.7\pm50.6[/math]	[math]426.63\pm0.84[/math]
PS1	[math]421917\pm649.5[/math]	10 min	[math]42191.7\pm64.9[/math]	[math]703.19\pm1.08[/math]
PS1+PS2	[math]1224\pm34.9[/math]	10 min	[math]122.4\pm3.5[/math]	[math]2.04\pm0.06[/math]