Difference between revisions of "Yields and Asymmetry for different detectors configurations."

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As we can see:
 
As we can see:
  
−
*The best case is of cause <math>4\pi</math> geometry. The 2n correlation yield is about 2.13 % with 2 MeV energy cuts .
+
*The best case is of cause <math>4\pi</math> geometry. Here:
−
*The next good case is detectors located in the plane perpendicular to the beam. The 2n correlation yield is about 0.92 % with 2 MeV energy cuts.
+
**with no energy cuts. Total yield is  100 %. Asymmetry yield is about 13 %. Asymmetry of 2n correlations is about 9.
 +
**2 MeV energy cuts. Total yield is  about 12 %. Asymmetry yield is about 2 %. Asymmetry of 2n correlations is about 65.
 +
*The next good case is detectors located in the plane perpendicular to the beam.
 +
**Total yield is about 3 %. Asymmetry yield is about 0.9 %. Asymmetry of 2n correlations is about 81.
 
*The worst case is detectors located in the plane parallel to the beam. The 2n correlation yield is about 0.05 % with 2 MeV energy cuts.
 
*The worst case is detectors located in the plane parallel to the beam. The 2n correlation yield is about 0.05 % with 2 MeV energy cuts.
 +
**Total yield is about 0.08 %. Asymmetry yield is about 0.05 %. Asymmetry of 2n correlations is about 30.
 +
  
 
===And let see how the 2n correlations looks like for different cuts===
 
===And let see how the 2n correlations looks like for different cuts===
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*2 MeV energy cuts. Total yield is 12 %. Asymmetry yield is about 2 %. Asymmetry of 2n correlations is about 65.
+
*2 MeV energy cuts. Total yield is about 12 %. Asymmetry yield is about 2 %. Asymmetry of 2n correlations is about 65.
  
 
[[File:Cos theta 2n cut1.png | 700px]]
 
[[File:Cos theta 2n cut1.png | 700px]]
  
  
−
*2 Mev energy cuts.  Plus angle cuts for each neutrons <math>|cos(\Theta_{a,b})<0.42|</math>. Total yield is 3 %. Asymmetry yield is about 0.9 %. Asymmetry of 2n correlations is about 81.
+
*2 Mev energy cuts.  Plus angle cuts for each neutrons <math>|cos(\Theta_{a,b})<0.42|</math>. Total yield is about 3 %. Asymmetry yield is about 0.9 %. Asymmetry of 2n correlations is about 81.
  
 
[[File:Cos theta 2n cut2.png | 700px]]
 
[[File:Cos theta 2n cut2.png | 700px]]
  
  
−
*2 MeV energy cuts.  Plus angle cuts for each neutrons <math>|cos(\Theta_{a,b})<0.9|</math>. Total yield is 0.08 %. Asymmetry yield is about 0.05 %. Asymmetry of 2n correlations is about 30.
+
*2 MeV energy cuts.  Plus angle cuts for each neutrons <math>|cos(\Theta_{a,b})<0.9|</math>. Total yield is about 0.08 %. Asymmetry yield is about 0.05 %. Asymmetry of 2n correlations is about 30.
  
 
[[File:Cos theta 2n cut3.png | 700px]]
 
[[File:Cos theta 2n cut3.png | 700px]]

Revision as of 18:01, 14 June 2011

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Follow are some Monte Carlo simulations of 2n correlations. One neutron are from one FF, two neutrons per fission. No accidental neutron was considered, all neutrons are correlated. Total 10M events was simulated. Every neutron was sampled up to 10 MeV. The polarization of gammas are zero.


Below is cos(Theta) of neutrons a and b in LAB frame. No energy cuts was made.

The spectrum is a convolution of the "initial" spectrum which the FF emits, and the kinematic effects due to the fragment recoil

Cos theta 1n nocut.png


Below is the same spectrum, but made with 2 MeV energy cuts.

Cos theta 1n cut1.png


Lets do some geometry cuts

Geometry of different cuts

Some results of 2n simulations for different cuts.

Table 2n yields.png

In the table above are:

  • cut1: 2 Mev energy cuts
  • cut2: 2 Mev energy cuts. Plus angle cuts for each neutrons [math]|cos(\Theta_{a,b})\lt 0.42|[/math]. That is detectors located in the plane perpendicular to the beam
  • cut3: 2 Mev energy cuts. Plus angle cuts for each neutrons [math]|cos(\Theta_{a,b})\gt 0.9|[/math]. That is detectors located in the plane parallel to the beam


  • cnts_nn_180: counts with angle between two neutrons are: [math]cos(\Theta_{nn})\lt -0.9[/math]. Anti-parallel neutrons.
  • cnts_nn_0: counts with angle between two neutrons are: [math]cos(\Theta_{nn})\gt 0.9[/math]. Parallel neutrons.


As we can see:

  • The best case is of cause [math]4\pi[/math] geometry. Here:
    • with no energy cuts. Total yield is 100 %. Asymmetry yield is about 13 %. Asymmetry of 2n correlations is about 9.
    • 2 MeV energy cuts. Total yield is about 12 %. Asymmetry yield is about 2 %. Asymmetry of 2n correlations is about 65.
  • The next good case is detectors located in the plane perpendicular to the beam.
    • Total yield is about 3 %. Asymmetry yield is about 0.9 %. Asymmetry of 2n correlations is about 81.
  • The worst case is detectors located in the plane parallel to the beam. The 2n correlation yield is about 0.05 % with 2 MeV energy cuts.
    • Total yield is about 0.08 %. Asymmetry yield is about 0.05 %. Asymmetry of 2n correlations is about 30.


And let see how the 2n correlations looks like for different cuts

  • No energy cuts. Total yield is 100 %. Asymmetry yield is about 13 %. Asymmetry of 2n correlations is about 9.

Cos theta 2n nocut.png


  • 2 MeV energy cuts. Total yield is about 12 %. Asymmetry yield is about 2 %. Asymmetry of 2n correlations is about 65.

Cos theta 2n cut1.png


  • 2 Mev energy cuts. Plus angle cuts for each neutrons [math]|cos(\Theta_{a,b})\lt 0.42|[/math]. Total yield is about 3 %. Asymmetry yield is about 0.9 %. Asymmetry of 2n correlations is about 81.

Cos theta 2n cut2.png


  • 2 MeV energy cuts. Plus angle cuts for each neutrons [math]|cos(\Theta_{a,b})\lt 0.9|[/math]. Total yield is about 0.08 %. Asymmetry yield is about 0.05 %. Asymmetry of 2n correlations is about 30.

Cos theta 2n cut3.png

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