Difference between revisions of "Photon flux proportionality"

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(Created page with "If we compare the photon flux from the two runs with DU target 2467 and 2506, 90 min long")
 
 
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If we compare the photon flux from the two runs with DU target
 
If we compare the photon flux from the two runs with DU target
  
2467
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run 2467 (7770 positrons total)
  
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[[File:flux_DU_r2467.png | 400 px]]
  
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and
 +
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run 2506 (30312 positrons total)
 +
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[[File:flux_DU_r2506.png | 400 px]]
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The average photon flux increased from 90 <math>e^+/min</math> to 350 <math>e^+/min</math> and the ratio is 350/90 = 3.9 .
 +
 +
In other way if we look at the ratio of the integral number of positrons produced during the runs 30312/7770 = 3.9
 +
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The number of neutrons used to do narmalization, i.e. the sum of the number of neutrons in three detectors placed at 0 deg left, 90 deg bottom and 0 deg right changed as follows:
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run 2467: SUM(0-90-0) = 518 neutrons
  
and
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run 2506: SUM(0-90-0) = 2195 neutrons
 +
 
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The neutron number ratio is 2195/518 = 4.2 .
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If we consider another run and compare with the run 2467 (see above)
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 +
run 2522 (19571 positrons total)
 +
 
 +
[[File:flux_DU_r2522.png | 400 px]]
 +
 
 +
If we look at the ratio of the integral number of positrons produced during the runs 19571/7770 = 2.52
 +
 
 +
run 2522: SUM(0-90-0) = 1271 neutrons
 +
 
 +
The neutron number ratio is 1271/518 = 2.45 .
  
2506, 90 min long
+
So the relative photon flux change is proportional to the relative number of prompt fission neutrons produced and normalization procedure using the SUM(0-90-0) is correct normalization for the asymmetry calculation.

Latest revision as of 20:22, 11 June 2013

If we compare the photon flux from the two runs with DU target

run 2467 (7770 positrons total)

Flux DU r2467.png

and

run 2506 (30312 positrons total)

Flux DU r2506.png

The average photon flux increased from 90 [math]e^+/min[/math] to 350 [math]e^+/min[/math] and the ratio is 350/90 = 3.9 .

In other way if we look at the ratio of the integral number of positrons produced during the runs 30312/7770 = 3.9

The number of neutrons used to do narmalization, i.e. the sum of the number of neutrons in three detectors placed at 0 deg left, 90 deg bottom and 0 deg right changed as follows:

run 2467: SUM(0-90-0) = 518 neutrons

run 2506: SUM(0-90-0) = 2195 neutrons

The neutron number ratio is 2195/518 = 4.2 .

If we consider another run and compare with the run 2467 (see above)

run 2522 (19571 positrons total)

Flux DU r2522.png

If we look at the ratio of the integral number of positrons produced during the runs 19571/7770 = 2.52

run 2522: SUM(0-90-0) = 1271 neutrons

The neutron number ratio is 1271/518 = 2.45 .

So the relative photon flux change is proportional to the relative number of prompt fission neutrons produced and normalization procedure using the SUM(0-90-0) is correct normalization for the asymmetry calculation.