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

And below my scope pictures of this rear event:

Let's do the random coincidence cosmic ray test again.

But now the distance between PS1 and PS2 is about 5 cm. And let's look on the coincidence signal between PS1 and PS2:

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

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

PS1 and PS2 are parallel to each other and are faced to the source.

the CF252 source in the middle

the distance between PS1(PS2) and source is 6 cm

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

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

Second the set up is like:

PS1 and PS2 are perpendicular to each other and are faced to the source.

the CF252 source in the middle

the distance between PS1(PS2) and source is 6 cm

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

	total counts	time	counts/min	counts/sec
PS1	[math]\displaystyle{ 250116\pm500.1 }[/math]	10 min	[math]\displaystyle{ 25011.6\pm50.0 }[/math]	[math]\displaystyle{ 416.86\pm0.83 }[/math]
PS1	[math]\displaystyle{ 414774\pm644.0 }[/math]	10 min	[math]\displaystyle{ 64.4\pm64.9 }[/math]	[math]\displaystyle{ 691.29\pm1.07 }[/math]
PS1+PS2	[math]\displaystyle{ 1359\pm36.9 }[/math]	10 min	[math]\displaystyle{ 135.9\pm3.7 }[/math]	[math]\displaystyle{ 2.26\pm0.06 }[/math]